AIR RESOURCES BOARD

HEAVY-DUTY VEHICLE SELECTIVE CATALYTIC REDUCTION

TECHNOLOGY FIELD EVALUATION

May 2011

This report has been reviewed by the staff of the California Air Resources 

Board and approved for publication. Approval does not signify that the 

contents necessarily reflect the views and policies of the Air Resources 

Board, nor does mention of trade names or commercial products constitute 

endorsement or recommendation for use.
TABLE OF CONTENTS

EXECUTIVE SUMMARY............................................................................................................................... i

I. Introduction......................................................................................................................................... 1

II. Investigation Plan............................................................................................................................... 3

A. DEF AVAILABILITY SURVEY ...........................................................................................................................3

1. First Survey, March 2010...........................................................................................................................3

2. Second Survey, August 2010.......................................................................................................................5

3. Conclusion..................................................................................................................................................6

B. DEF QUALITY TAMPERING SURVEY................................................................................................................7

1. DEF Quality Analysis.................................................................................................................................8

2. Driver Warning Indicators.........................................................................................................................9

3. Driver’s Questionnaire...............................................................................................................................9

4. Conclusion................................................................................................................................................10

C. EVALUATION OF SCR DRIVER INDUCEMENTS ...............................................................................................10

1. Test Vehicle 1 ...........................................................................................................................................15

2. Test Vehicle 2 ...........................................................................................................................................21

3. Test Vehicle 3 ...........................................................................................................................................29

III. Overall Conclusions......................................................................................................................... 39

IV. Appendix A – Field Survey Forms.................................................................................................. 42

V. Appendix B – SCR Test Plan (2R1004)........................................................................................... 46
i

EXECUTIVE SUMMARY

The California Air Resources Board (ARB) and the United States Environmental 

Protection Agency (U.S. EPA) adopted a 0.20 gram per brake horsepower-hour oxides 

of nitrogen (NOx) standard for heavy duty diesel (HDD) 2010 model year (MY) engines. 

The majority of engine manufacturers chose selective catalytic reduction (SCR) 

technology to attain this standard. For SCR systems to operate properly, unlike most 

emission control systems, the operator needs to periodically replenish the reductant 

used to catalyze the NOx conversion. The 2010 MY engines equipped with SCR all 

used a liquid urea solution as the reductant, known commonly as diesel exhaust fluid 

(DEF). Using DEF adds a nominal operational cost to businesses, theoretically creating 

an incentive for operators to find ways to circumvent the SCR system and reduce costs 

by minimizing DEF usage. Concerns were raised during the original rulemaking efforts 

that because SCR relies on the availability of DEF and truck operators periodically 

refilling their DEF tanks, SCR could be construed as not being an effective emission 

reduction strategy. In addition, since the use of DEF would likely be seen as an 

increase in operational cost, the threat of tampering existed. 

To minimize the likelihood of improper maintenance and tampering, the U.S. EPA 

provided manufacturers certification guidance for SCR-equipped engines in the 2007 

calendar year, in February 2009, and again in December of 2009 (U.S. EPA reference 

numbers CISD-07-07 dated March 27, 2007 and CISD-09-04 dated February 18, 2009 

and CISD-09-04 REVISED dated December 30, 2009). While the guidance documents 

were not considered policy by the ARB, ARB provided comments during the 

development of the February 2009 U.S. EPA Guidance and consulted the February 

2009 Guidance during its 2010 certification reviews for California. Most manufacturers 

were already certified for the 2010 MY when the December 2009 U.S. EPA Guidance 

was released. 

The February 2009 U.S. EPA Guidance document provided advisory information to 

manufacturers of SCR-equipped engines that addressed driver warning systems, driver 

inducement strategies, identification of incorrect reducing agents (also known as DEF), 

tamper resistant design, and freeze protection. 

ARB consulted the February 2009 document during its 2010 MY certification review and 

expected at a minimum that engines seeking ARB certification would have attributes 

consistent with the February 2009 U.S. EPA Guidance. In addition, as a condition of 

certification, ARB requires manufacturers to demonstrate that all emission control 

systems are tamper resistant. In the case of SCR, which requires the routine addition of 

DEF, most manufacturers utilized driver inducements to demonstrate tamper resistance 

when certifying their vehicles. Consistent with the February 2009 U.S. EPA Guidance, 

these inducements first alert the driver that the DEF supply is low, followed by a 

reduction in truck performance or other inducement to encourage the DEF supply to be 

refilled. Ultimately, if DEF is not refilled, or if an inappropriate fluid is added, or if 
ii

hardware is tampered, the vehicle is immobilized. The ARB certified 2010 MY engines 

that had strategies consistent with the February 2009 U.S. EPA Guidance. 

One manufacturer that did not use SCR, Navistar, claimed in a July 2010 public 

workshop, based on their own test program that the warning and driver inducements 

used for the 2010 MY engines were not effective in deterring drivers from not refilling 

DEF or otherwise tampering with the DEF dispensing system. In response to the 

concerns of DEF availability, SCR tampering, and effectiveness of SCR inducement 

strategies, ARB initiated field investigations to evaluate the first year implementation of 

SCR - the 2010 MY. The investigation included: (1) two surveys of DEF availability 

within the State of California; (2) a survey to determine whether truck operators driving 

2010 MY SCR-equipped trucks on California roadways have tampered with SCR 

components or are not using DEF; (3) an examination of the types and effectiveness of 

SCR driver inducements employed on 2010 MY HDD vehicles; and (4) an examination 

of the emission impacts of HDD SCR-equipped vehicles when DEF has been depleted, 

diluted or the SCR system has been tampered. 

A summary of the findings follows.

1. Availability of DEF – Two surveys of DEF availability were performed, one in March 

2010 and the second in August 2010. Both surveys indicated that DEF was readily 

available at major diesel truck stop refueling stations, 85% and 92%, respectively. In 

addition, both surveys indicated that 30% of retailers that normally supply parts and 

equipment for light-, medium-, and HDD vehicles and trucks had DEF available. ARB 

anticipates that as the demand for DEF increases, it’s availability at retailers will 

increase. 

2. Is DEF being used? Are SCR systems being tampered with? – During the first 

two weeks of September 2010, the staff pulled over as many identifiable SCR-equipped 

trucks as possible at seven California Highway Patrol commercial vehicle weigh stations 

and performed roadside inspections on each vehicle to determine if DEF was being 

used and if other indications of tampering (warning lights or messages) were present. 

The results indicated that all 69 vehicles inspected were using the proper DEF solution, 

no tampering was present, and no DEF-related warning lights or audible alerts had 

been initiated. 

A survey of the operators indicated that 60 of the 69 drivers had no problem locating 

DEF while nine drivers indicated they had experienced problems. Of these nine drivers, 

four had problems locating DEF out-of-state and the other five had problems locating 

DEF in California (i.e., the owner could not purchase DEF at a particular diesel refueling 

station or the station had run out of supply). However, 68 drivers stated that they never 

ran out of DEF while operating their vehicles and only 1 driver indicated that he drove 

for only 10 miles with an empty DEF tank as indicated by the driver’s gauge. 
iii

3. Evaluation of SCR inducements: - ARB procured three 2010 trucks that use SCRequipped engines for more thorough evaluation. Before testing the vehicles, ARB staff 

examined the vehicle owner’s manuals and the February 2009 U.S. EPA Guidance to 

ascertain the expected inducement strategies for each vehicle in the ARB evaluation 

program. Typically, these include a sequence of visual and/or audible warnings on the 

instrument panel (e.g. warning lights, chimes, and/or text message displays) indicating 

DEF supply was low or a problem had been identified. As additional mileage is 

accumulated without remedying the problem or refilling the DEF supply, further driver 

inducements should occur, such as power de-rates or speed limits (which allow 

continued operation of the truck). Ultimately, if the problem is not corrected a severe 

inducement or final immobilization in the form of a no-start condition, or 5 mile per hour 

(mph) maximum speed limit, or idle-only operation should be triggered once the vehicle 

reaches a safe harbor (e.g. when diesel refueling occurred, or the engine was turned 

off, or the vehicle was parked or idled for an extended period of time). The specific 

inducements for each engine evaluated are discussed below.

The evaluation focused on three vehicles with 2010 MY engines equipped with SCR 

systems. The vehicles evaluated included a 2011 Freightliner Cascadia equipped with 

a 2010 MY12.8 liter Detroit Diesel DD13 engine (Test Vehicle 1), a 2011 MY Kenworth 

T800 equipped with a 2010 MY 14.9 liter Cummins ISX15 engine (Test Vehicle 2), and 

a 2011 MY Dodge Cab Chassis D5500 equipped with a 2010 MY 6.7 liter Cummins ISB 

engine (Test Vehicle 3). Each vehicle was operated under the following test conditions 

to determine when driver inducements were initiated, how effective they were, how they 

compared to what was expected from reviewing the vehicle owner’s manuals, and 

consistency with the February 2009 U.S. EPA Guidance.

• DEF Depletion Cycle –The vehicle would be operated until the DEF tank was 

depleted and the vehicle experienced a no-start condition, or 5 mile per hour (mph) 

maximum speed limit, or idle-only operation. According to the February 2009 U.S. 

EPA Guidance the following scenarios should occur. As DEF depletes, visual 

and/or audio alerts should warn the driver that the tank needed refilling. As DEF 

continues to deplete to empty, the driver may experience an engine power de-rate 

condition ranging between 25% to 40% depending on the vehicle type and DEF 

tank capacity. Typically, the first level inducement should begin at a 2.5% DEF 

level known as the DEF Trigger and should be in the form of either a 25% engine 

power de-rate or some maximum speed limit chosen by the manufacturer, and at 

that point the search for severe inducement should begin. The severe inducement 

or final immobilization should occur once a safe harbor event (diesel refuel, 

park/idle, engine restart) was reached any time after the 2.5% DEF Trigger. It is 

important to note that vehicle gauge levels may be calibrated to read lower than 

actual DEF tank level to build in reserve tank volume, e.g., 2.5% actual DEF level 

might read as 0% on the driver's gauge. Thus in some cases the DEF is still being 

injected into the SCR when the DEF gauge reads empty.
iv

• DEF Contamination Cycle – The vehicle would be operated with water instead of 

DEF until the vehicle experienced a no-start condition, or 5 mile per hour (mph) 

maximum speed limit, or idle-only operation. According to the February 2009 U.S. 

EPA Guidance the following scenarios should occur. The detection of poor DEF 

quality should trigger initial visual and/or audible warnings. If no remedy occurred, 

an engine power de-rate should occur at 500 miles or 10 hours after initial 

detection, and severe inducement or final immobilization should occur once a safe 

harbor event (diesel refuel, park/idle, engine restart) was reached following 1,000 

miles or 20 hours after the initial detection and warning. 

• DEF System Tampering Cycle – Following the disabling of the DEF system by 

ARB staff, the vehicle would be operated until it experienced a no-start condition,

or 5 mile per hour (mph) maximum speed limit, or idle-only operation. According to 

the February 2009 U.S. EPA Guidance, the following scenarios should occur. The 

detection of tampering should occur quickly depending on the particular tampering 

event triggering visual and/or audible warnings. If no remedy is sought, an initial 

25% engine torque power de-rate should occur at 500 miles or 10 hours after the 

initial detection, and severe inducement or final immobilization should occur once a 

safe harbor event (diesel refuel, park/idle, engine restart) was reached following 

2,000 miles or 40 hours after initial detection and warning. 

DDC 12.8L (Test Vehicle 1): Based on the vehicle owner’s and engine service 

manuals, the vehicle was expected to have escalating visual warnings, vehicle speed 

limited to 55 mph combined with a 25% reduction in engine torque, and a severe

inducement limiting vehicle speed to 5 mph once a safe harbor event (in this case a 

diesel refueling event, or 350 gallons of diesel fuel consumed and engine stop) was 

encountered. 

During the DEF Depletion Cycle, the vehicle performed as expected per the vehicle 

owner’s and engine service manuals. The cycle began with the DEF gauge illuminating 

one green square gauge light (DEF gauge only shows increments of approximately 25% 

through the use of four squares) indicating sufficient DEF was present to not trigger any 

warnings or alerts. Visual warnings (a solid amber circle lit up and one solid green 

square changed to amber) began 185 miles after starting the cycle, presumably, when 

the DEF level should have dropped below 10% DEF (based on the vehicle manuals). 

The SCR system escalated the driver warning sequence 77 miles after the initial 

warnings with a flashing amber circle, a flashing red square, and illumination of the 

amber text check engine light, consistent with the vehicle manuals 5% DEF level 

indicators. The visual warnings were accompanied by the driver noticing the vehicle 

speed was limited to about 55 mph, which would be consistent or ahead of the U.S. 

EPA Guidance 2.5% DEF Trigger for first level inducement. The driver experienced an 

engine power de-rate when negotiating a steep grade 33 miles later and the engine 

manufacturer diagnostic (EMD) malfunction indicator light (MIL) began flashing 

periodically. Staff drove for another 233 miles at which point the EMD MIL came on and 

stayed on. After another 40 miles, staff stopped the vehicle to refuel with 57.8 gallons 
v

of diesel fuel. Upon restart the red text stop engine light illuminated and the vehicle 

would not operate above 5 mph; all accumulated visual warnings continued to 

illuminate. The inducement strategies used on this truck to detect DEF depletion 

appear to be consistent with both the vehicle manuals and the February 2009 U.S. EPA 

Guidance.

To initiate the DEF Contamination Cycle, staff added about three gallons of water, 

which cleared the depletion inducements. Within an hour (41 miles of driving) of adding 

water to the DEF tank, the visual warnings (flashing amber DEF circle, amber text check 

engine light, amber EMD MIL) occurred indicating the detection of poor quality DEF. 

After driving an additional 345 miles with the continuance of visual warnings, the truck 

experienced an engine power de-rate coupled with a 55 mph maximum speed limit 

(consistent with the February 2009 U.S. EPA Guidance of 500 miles to trigger de-rate 

post detection). The vehicle was driven for another 504 miles until a diesel refueling 

was needed. After turning off the engine, and filling the diesel tank with 101 gallons of 

diesel, the vehicle was restarted and staff encountered the 5 mph severe inducement 

condition (consistent with the February 2009 U.S. EPA Guidance of 1,000 miles to 

trigger final immobilization post detection). The inducement strategies used on this 

truck appeared to be consistent with both the vehicle manuals and the February 2009 

U.S. EPA Guidance. Staff siphoned out the water and added twelve and a half gallons 

of DEF to clear the inducements but this was not successful; therefore, the vehicle was 

taken to a repair center where they reset the engine control unit (ECU) removing all 

inducement conditions. ARB was charged $240 for this service. 

On the DEF System Tampering Cycle, staff disconnected the DEF injection pump and 

upon starting the vehicle visual warnings (amber text check engine light and EMD MIL) 

were immediately illuminated. After driving 56 miles the engine power de-rate condition 

occurred (consistent with both the vehicle manuals and February 2009 U.S. EPA 

Guidance). Due to time constraints, ARB had to terminate testing of this vehicle and did 

not complete the final stages of inducements for this test cycle.

Regarding the effectiveness of the inducement strategies, ARB staff reported that visual 

warnings were effective in drawing the driver’s attention to the need for SCR-related 

service. Also, driving this vehicle once the initial inducement occurred (engine power 

de-rate and 55 mile per hour speed limit) was neither acceptable nor tolerable when 

trying to accelerate or driving uphill, and would likely cause a driver to refill with DEF or 

correct the SCR problem. In addition, once the vehicle entered into a 5 mph limited 

speed condition under a DEF contamination event, the only way to resume normal 

operation was to have the vehicle serviced, drain water out of the system and refill the 

vehicle with DEF, followed by a reset of the system by an authorized service technician; 

therefore, the driver would be stranded until proper servicing. The ARB staff concludes 

the inducements were effective for this vehicle because the constant inducement 

strategies and risk of costly repairs were not worth the lost time and financial business 

losses when DEF could simply be added to ensure proper vehicle operation. 
vi

Cummins 14.9L (Test Vehicle 2): Based on the vehicle owner’s manual, the vehicle 

was expected to have visual warnings, a 25% reduction in engine torque for the initial 

de-rate, and a severe inducement limiting vehicle speed to 5 mph once a safe harbor 

(key-off/restart, or 20 hour idle) event was encountered. 

During the DEF Depletion Cycle, the first visual warnings (solid DEF gauge light, low 

DEF message) occurred when the DEF gauge level fell below 1/8th tank level. After 

driving 44 additional miles, the red DEF light began to flash. The check engine light 

also illuminated 24 miles later when the DEF gauge read empty and was followed in 

another 130 miles by an engine torque reduction as experienced by the driver. Even

after driving an additional 559 miles after encountering an engine torque de-rate, 

repeated key-on/key-off events did not trigger the 5 mph inducement. It should be 

noted since taking delivery of this vehicle from the dealer, the on-board diagnostic 

(OBD) MIL and the stop engine light intermittently illuminated that was later determined 

to be related to a throttle position sensor problem. While the vehicle’s early warning 

and first level inducements were consistent with the February 2009 U.S. EPA Guidance, 

the severe inducement never occurred. Staff investigation found that approximately one 

quart of DEF remained in the DEF tank; therefore, the vehicle never triggered the zero 

DEF inducement. When the remaining DEF was siphoned out, the 5 mph inducement 

was triggered immediately. Further discussion of the intermittent throttle position sensor 

problem and residual DEF issue is provided below.

To initiate the DEF Contamination Cycle, staff added water to the DEF tank. After 

driving 57 miles with water in the DEF tank, the vehicle returned to normal operation 

and all visual warnings cleared. Poor quality DEF was detected after driving an 

additional 582 miles with illumination of an OBD MIL. An engine power de-rate was felt 

by the driver 225 miles later. Staff drove the vehicle for another 686 miles with 

intermittent engine power de-rate fluctuations and visual warnings. However, the 

vehicle never triggered the 5 mph severe inducement after driving 911 miles (and more 

than 30 hours) since the first warning occurred and with multiple key off events. The 

inducement strategies demonstrated for this cycle were inconsistent with the February 

2009 U.S. EPA Guidance and the vehicle owner’s manual. After the DEF gauge read 

near empty, staff added DEF several times over the next 143 miles until the DEF gauge 

read almost full, yet staff was unable to clear the OBD MIL or engine power de-rate 

conditions. The vehicle was taken to a Cummins dealer, who in their investigation of 

the problem confirmed the DEF tank was contaminated with water and declined any 

warranty coverage for the repair, which was verbally estimated to be $800. ARB 

declined the service, but requested that the dealer reset the computer and clear any 

trouble codes which cost $125. 

While at the dealer, it was also discovered that the vehicle had a defective throttle 

position sensor and that it caused numerous OBD MIL illuminations along with the red 

engine stop light, causing an associated engine power de-rate. The engine de-rate 

condition as a result of the throttle position sensor problem was different than the SCR 

inducement engine de-rate because the OBD MIL and de-rate event could be quickly 
vii

cleared by snapping the accelerator throttle. The throttle position sensor was replaced 

under warranty at a second dealer visit and the Contamination Cycle halted. 

For the DEF Tampering Cycle, the DEF system was flushed, appropriate DEF was 

added, and staff disconnected the DEF doser valve. Immediately upon engine start, the 

check engine light was illuminated and after driving 97 miles (consistent with the 

February 2009 U.S. EPA Guidance detection time and 500 mile triggers) additional 

visual warnings occurred (flashing DEF light, stop engine light, and low DEF fluid) along 

with a perceived engine power de-rate. However, as with the DEF Contamination 

Cycle, despite 2,552 additional miles driven and multiple key-off/restarts, the 5 mph 

speed limit could not be initiated, which is inconsistent with the final immobilization as 

outlined in the February 2009 U.S. EPA Guidance and the vehicle owner’s manual.

Regarding the effectiveness of the inducements for this vehicle, ARB staff reported that 

visual warnings were effective in drawing the driver’s attention to the need for DEF 

service. However, since the throttle position sensor was suspected of causing engine

power fluctuations during the DEF Depletion and Contamination Cycles, staff could not 

objectively rate the effectiveness of the engine power de-rate under those cycles 

because it was not clear if de-rate occurred because of a detected SCR problem or was 

the result of the defective throttle position sensor. However, even after the throttle 

position sensor was repaired, the engine power de-rate caused the vehicle to lose 

power and reduce vehicle speed when negotiating uphill or accelerating, but was 

seldom noticed when driving on level ground. The drivers reported that the Cummins 

engine power de-rate was not as noticeable as the DDC vehicle engine power de-rate 

at similar power and engine speeds.

ARB staff contacted Cummins regarding the failure of the vehicle to initiate the 5 mph 

speed limit severe inducement under the depletion, contamination and tampering 

scenarios. Cummins had already implemented a change to correct the failure to initiate 

the severe inducement on their engine production line in the second quarter of 2010 

and had launched a voluntary recall (Cummins Campaign C1036) in August of 2010. 

Staff confirmed that the ARB test vehicle had not yet been recalled and fixed per 

C1036. Since completing this test program, Test Vehicle 2 has been outfitted with the 

Cummins’ recall fix and ARB is currently re-evaluating these cycles. 

Cummins 6.7L (Test Vehicle 3): Based on the vehicle owner’s manual, the vehicle was 

expected to have escalating visual warnings and audible chimes, followed by a 500 mile

countdown counter if no action is taken. Once the counter reaches zero miles and no 

action has been taken, the vehicle should not start upon its next key-off/key-on event. 

For the DEF Depletion Cycle, the 500 mile countdown should start 500 miles before

DEF is depleted, while for the DEF Contamination and DEF Tampering Cycles the 500 

mile countdown sequence should begin if no remedy is sought after operating 250 miles 

after detection. For all cycles a no-start event should occur once the counter reaches

zero and the vehicle is turned off. For this vehicle, the manufacturer chose not to 

implement a first level inducement as outlined in the February 2009 U.S. EPA Guidance 
viii

with the aim of meeting the severe inducement or final immobilization point using a 

countdown counter. 

 

During the DEF Depletion Cycle, a visual text message “Low DEF Refill Soon” came on 

for the first time at approximately 16% DEF gauge level and displayed periodically with 

an audible chime as the DEF level declined. After driving 195 miles since the first low 

DEF message appeared, the EMD MIL illuminated (due to a DEF heater malfunction, 

see below). A new test message "Refill DEF Engine Will Not Restart in 500 Miles” 

displayed 739 miles after the EMD MIL was first observed and triggered the 500 mile 

countdown. At this time, with the EMD MIL illuminated again (EMD MIL went on and off 

throughout this cycle) the DEF gauge read 0%. During the 500 mile countdown 

sequence a message continuously displayed "Refill DEF Engine Will Not Restart in XXX 

Miles" and the audible chimes became more frequent as the countdown progressed. 

The vehicle was shut down overnight 97 miles into the countdown. Upon restarting the 

vehicle the next day, the DEF gauge showed 1%, compared to 0% the night before, and 

the countdown had been cleared. Mileage accumulation began again and after driving 

35 miles the DEF gauge again reached 0% triggering the 500 mile countdown sequence 

once more. Upon locating a safe harbor location 497 miles after the countdown 

sequence began the second time, the vehicle underwent a key-off/key-on event and a 

no-start condition resulted. The truck’s inducements appeared to be generally 

consistent with the vehicle owner's manual; however, the mileage accumulation seemed 

excessive for the amount of DEF consumed. Upon investigation, it was discovered that 

a DEF heater malfunction was causing suspension of DEF dosing under certain 

conditions, thus extending the miles driven before DEF depletion occurred. While the 

vehicle was, in general, consistent with the intentions of the February 2009 U.S. EPA 

Guidance, the mileage accumulation was too high for the appropriate DEF consumption 

rate expected; however, this was related to the DEF heater glitch (DEF engine coolant 

control valve). Staff is unclear as to why the vehicle reset the 500 mile counter when 

the DEF gauge changed from 0% to 1% after an overnight park and is following up with 

Cummins’ personnel on this issue. 

To initiate the DEF Contamination Cycle, the DEF tank was filled with water, which 

cleared the no-start condition. Detection of water in the DEF tank occurred after 

accumulating 12 miles of driving, which caused a visual warning “Service DEF System -

See Dealer” and the EMD MIL illuminated on the instrument panel. Two hundred forty 

nine (249) miles later, the 500 mile countdown initiated alerting the driver that the 

vehicle will not start after 500 miles, accompanied by periodic chimes as the countdown 

progressed. After driving another 497 miles, the countdown indicated zero remaining 

miles. At the first safe opportunity, the vehicle was keyed-off and attempts to restart the 

vehicle failed. The vehicle had been driven a total of 746 miles after initial detection of 

poor quality DEF. Since the manufacturer chose to use a countdown to no-start 

inducement strategy versus a power de-rate or speed limiter as the first level 

inducement we cannot compare directly with the first inducement level in the February 

2009 U.S. EPA Guidance. However, the vehicle reached the no-start event well before 
ix

the February 2009 U.S. EPA Guidance 1,000 mile after detection severe inducement

trigger point. 

 

In order to initiate the DEF System Tampering cycle, staff drained the water from the 

DEF tank, filled the tank with appropriate DEF, cleared the diagnostic trouble codes and 

the no-start condition using a scan tool, and disconnected the DEF doser injector to 

represent tampering. The tampering was detected immediately upon starting the 

engine and the driver was alerted of the problem through the illumination of the EMD 

MIL, an audible chime, and the displayed message “Service DEF System - See Dealer.” 

After 250 miles of driving, the message changed to "Service DEF System Engine Will 

Not Start in 500 miles – See Dealer". Another 496 miles were driven before the 

countdown expired. At the first safe opportunity, the vehicle was keyed-off and attempts 

to restart the truck failed. In total, the vehicle was driven 746 miles after the initial 

detection of DEF tampering. The inducement strategies used on this vehicle to detect 

DEF system tampering were consistent with the February 2009 U.S. EPA Guidance and 

well within its 2,000 mile after detection severe inducement trigger point. 

Regarding the effectiveness of the inducement strategies, ARB staff reported that visual 

and audible warnings/alerts were effective in drawing the driver’s attention for the need 

of SCR-related service. Although this sequence was different than the other two trucks 

evaluated in this report, the 500 mile countdown to a no-restart condition was an 

effective strategy in motivating the driver to pay attention to SCR required service. 

However, the DEF heater malfunction caused more miles than expected to be 

consumed before final immobilization was encountered during the DEF Depletion event. 

Therefore, while the inducement strategies were consistent with the February 2009 U.S. 

EPA Guidance for the majority of the testing, further evaluation is warranted on this 

vehicle once the DEF heater malfunction is corrected. 

Cummins was already aware of the DEF heater issue and has addressed this problem 

through a service campaign (Technical Service Bulletin No. 25-002-10). Another issue 

identified by staff was that this system could be reset with a generic scan tool, which 

allowed the vehicle to continue operation. ARB has discussed the scan tool issue with 

all manufacturers, pointing out that this capability is not acceptable and has indicated to 

manufacturers that it must be corrected as soon as possible, but in no case later than 

the 2013 model year. 

4. NOx emissions evaluation – To determine the impact on NOx emissions, Test 

Vehicle 3 was outfitted with a Sensors, Inc., Semtech-DS Portable Emissions 

Measurement System allowing for real-time emissions readings as the vehicle was 

operated through the different DEF test cycles noted above. Measurements from Test 

Vehicle 3 showed that NOx emissions were within control limits when operating with 

DEF and tampering was not present. When staff used water in place of DEF and 

tampered with the SCR system, the NOx emissions were about four times higher than 

under normal operation. 
x

Conclusion

The widespread availability of DEF was uncertain prior to the first year of sale in the 

U.S. of SCR-equipped engines (2010). The EPA guidance accommodated this 

uncertainty by allowing the engine to be designed to allow for some operation of the 

truck after the warning system indicated DEF was soon to be depleted. The purpose of 

this provision was to allow the truck operator several opportunities to procure DEF 

before the more disabling inducements were initiated. As the ARB survey showed, a 

small percentage of operators found DEF unavailable during 2010. The survey also 

showed, however, that DEF was widely available, and only 1 of 69 truck operators 

operated their truck without DEF because of DEF unavailability. 

For the three vehicles evaluated in this study, ARB staff found that the warnings and 

inducement strategies incorporated by the engine manufacturers were consistent with 

the February 2009 U.S. EPA Guidance. However, the large Cummins engine had a 

programming error that caused the intended severe inducement (5 mph maximum 

operating speed) to not occur. Cummins has recalled the affected engines and has also 

made the change in production. The test vehicle also had a defective throttle position 

sensor which made assessing the effectiveness of the power de-rate strategy difficult to 

assess. The smaller Cummins engine had a defective DEF heater which caused the 

truck to operate longer than anticipated before DEF depletion was detected. This has 

been addressed by Cummins with a service campaign. 

Changes for 2011 Models

With DEF widely available in California, ARB has worked with the U.S. EPA and engine 

manufacturers to improve the effectiveness of the SCR monitoring system of 2011 

models. In July 2010, ARB held a joint public workshop with the U.S. EPA discussing 

the changes to the SCR inducement strategies we expected for the 2011 and future 

MYs, as outlined below: 

a. When a low level of DEF remains, for example, sufficient to drive about 100 

miles under typical driving conditions, warning signals begin and become 

increasingly urgent thereafter.

b. After the DEF tank level triggered in paragraph (a) and before an empty DEF 

tank, a noticeable de-rate begins and is sustained until paragraph c.

c. When the DEF tank is empty, a more significant de-rate occurs. Operation at 

this second de-rate occurs no longer than necessary to safely reach a 

location where the engine can be safely shut down, for example, no more 

than one hour. At the end of this period, the vehicle speed is limited to 5 mph 

maximum.

d. Upon a disconnected SCR monitor, sensor, or component, warning signals 

begin and become increasingly urgent thereafter and the engine power will be 

noticeably de-rated.
xi

e. After an hour of operation pursuant to paragraph d., a second significant derate will occur. The engine will operate at this de-rated level for no longer 

than necessary to confirm disconnection, for example, no more than four 

hours. At the end of this period the vehicle speed is limited to 5 mph 

maximum. Normal operation cannot be resumed until the disconnection is 

cleared.

f. If repeated disconnects and reattachments of a SCR monitor, sensor, or 

component are detected, the attributes in paragraph c. apply. Normal 

operation cannot be resumed until the disconnections are cleared.

g. Proper DEF dosing should occur within 40 minutes of a freezing event.

In addition to the above, ARB is also expecting improvements in DEF contamination 

detection and in making systems unable to clear triggered inducements with generic 

scan tools.
1

HEAVY-DUTY VEHICLE SCR TECHNOLOGY FIELD EVALUATION

I. Introduction

The California Air Resources Board (ARB) and the United States Environmental 

Protection Agency (U.S. EPA) adopted a 0.20 gram per brake horsepower-hour oxides 

of nitrogen (NOx) standard for heavy duty diesel (HDD) 2010 model year (MY) engines. 

The majority of engine manufacturers chose selective catalytic reduction (SCR) 

technology to attain this standard. For SCR systems to operate properly, unlike most 

emission control systems, the operator needs to periodically replenish the reductant 

used to catalyze the NOx conversion. The 2010 MY engines equipped with SCR all 

used a liquid urea solution as the reductant, known commonly as diesel exhaust fluid 

(DEF). Using DEF adds a nominal operational cost to businesses, theoretically creating 

an incentive for operators to find ways to circumvent the SCR system and reduce costs 

by minimizing DEF usage. Concerns were raised during the original rulemaking efforts 

that because SCR relies on the availability of DEF and truck operators periodically 

refilling their DEF tanks, SCR could be construed as not being an effective emission 

reduction strategy. In addition, since the use of DEF would likely be seen as an 

increase in operational cost, the threat of tampering existed. 

To minimize the likelihood of improper maintenance and tampering, the U.S. EPA 

provided manufacturers certification guidance for SCR-equipped engines in the 2007 

calendar year, in February 2009, and again in December of 2009 (U.S. EPA reference 

numbers CISD-07-07 dated March 27, 2007 and CISD-09-04 dated February 18, 2009 

and CISD-09-04 REVISED dated December 30, 2009). While the guidance documents 

were not considered policy by the ARB, ARB provided comments during the 

development of the February 2009 U.S. EPA Guidance and consulted the February 

2009 Guidance during its 2010 certification reviews for California. Most manufacturers

were already certified for the 2010 MY when the December 2009 U.S. EPA Guidance 

was released. 
2

The February 2009 U.S. EPA Guidance document provided advisory information to 

manufacturers of SCR-equipped engines that addressed driver warning systems, driver 

inducement strategies, identification of incorrect reducing agents (also known as DEF), 

tamper resistant design, and freeze protection. 

ARB consulted the February 2009 document during its 2010 MY certification review and 

expected at a minimum that engines seeking ARB certification would have attributes 

consistent with the February 2009 U.S. EPA Guidance. In addition, as a condition of 

certification, ARB requires manufacturers to demonstrate that all emission control 

systems are tamper resistant. In the case of SCR, which requires the routine addition of 

DEF, most manufacturers utilized driver inducements to demonstrate tamper resistance 

when certifying their vehicles. Consistent with the February 2009 U.S. EPA Guidance, 

these inducements first alert the driver that the DEF supply is low, followed by a 

reduction in truck performance or other inducement to encourage the DEF supply to be 

refilled. Ultimately, if DEF is not refilled, or if an inappropriate fluid is added, or if 

hardware is tampered, the vehicle is immobilized. The ARB certified 2010 MY engines 

that had strategies consistent with the February 2009 U.S. EPA Guidance. 

One manufacturer that did not use SCR, Navistar, claimed in a July 2010 public 

workshop, based on their own test program that the warning and driver inducements 

used for the 2010 MY engines were not effective in deterring drivers from not refilling 

DEF or otherwise tampering with the DEF dispensing system. In response to the 

concerns of DEF availability, SCR tampering, and effectiveness of SCR inducement 

strategies, ARB initiated field investigations to evaluate the first year implementation of 

SCR - the 2010 MY. The investigation included: (1) a survey of DEF availability within 

the State of California; (2) two surveys to determine whether truck operators driving 

2010 MY SCR-equipped trucks on California roadways have tampered with SCR 

components or are not using DEF; (3) an examination of the types and effectiveness of 

SCR driver inducements employed on 2010 MY HDD vehicles; and (4) an examination 

of the emission impacts of HDD SCR-equipped vehicles when DEF has been depleted, 

diluted or the SCR system has been tampered.
3

II. Investigation Plan

In response to the concerns of DEF availability, SCR tampering, and effectiveness of 

SCR inducement strategies, ARB initiated field investigations to evaluate the first year 

implementation of SCR - the 2010 MY. The investigation included: (1) a survey of DEF 

availability within the State of California; (2) a survey to determine whether truck 

operators driving SCR-equipped vehicles on California roadways have tampered with 

SCR components or are not using DEF; (3) an examination of the types and 

effectiveness of SCR driver inducements employed on 2010 MY HDD engines; and (4) 

an examination of the emission impacts of HDD SCR-equipped vehicles when DEF has 

been depleted, diluted or the SCR system has been tampered. 

A. DEF Availability Survey

Two surveys were conducted to evaluate the availability of DEF throughout California

(see Appendix A). The first survey was conducted between March 15-18, 2010 and the 

second survey was conducted during the period August 2-11, 2010.

1. First Survey, March 2010

Using directories and maps as guides, field staff visited numerous businesses that were 

selling DEF during the week of March 15-18, 2010. The types of businesses visited 

included retail HDD truck stops, commercial fleets, vehicle service stations, auto part

stores, and automobile dealerships selling diesel vehicles with SCR technology. In 

general, the sites visited were along Interstate 5, Highway 99, Interstate 10, Interstate 

15, and U.S. Route 101. Furthermore, telephone surveys were also conducted to 

supplement the on-site surveys. Staff also surveyed DEF marketing web sites at 

www.finddef.com and www.discoverdef.com that identified known DEF distributors. As 

part of the survey, staff questioned management personnel at all the contacted sites to 

determine if DEF was available or if their company would be selling DEF in the future. 

ARB staff also inquired how DEF was sold, what size containers were available and the 

cost of DEF. The survey results indicated that a typical truck driver could easily find 

DEF at diesel refueling stations along major interstate routes or at an authorized repair 

dealer (i.e., 85% of these known distributors had DEF in stock), (see Figure 1). 
4

Figure 1 – DEF Survey – March 2010

DEF Availability Survey Results

March 2010

Have 

DEF

Available

No

DEF 

Available

DEF

To Be Sold 

Within 

6 Months

Total % Have 

DEF

% DEF To Be 

Sold Within 

6 Months

Known DEF 

Dealers* 33 6 4 39 85% 10%

Random Retail 

Facilities 60 211 34 271 22% 13%

* Includes diesel re-fueling stations and diesel repair facilities.

In addition, ARB’s survey showed that approximately one out of five retail facilities (i.e., 

auto part stores, light/medium-duty vehicle diesel refueling stations, major shopping 

retail stores, etc.) had DEF available.

Staff visited two Pilot Travel Center diesel refueling stations located in Madera and 

Hesperia, California that sold DEF in bulk quantity. These diesel refueling stations had 

DEF available next to the diesel pumps and dispensed DEF in a similar manner as 

diesel fuel. The cost for DEF at these locations averaged $2.89 per gallon and was the 

best overall cost per gallon identified by this survey. Most other diesel refueling stations 

had DEF available but it was located less conveniently inside the store or facility. Within 

the stores or facilities, DEF was available in 1.0, 2.0, 2.5 or 5 gallon containers. In 

some cases, DEF supply companies sold mainly 55 gallon or 275 gallon containers to 

HDD vehicle warehouses and truck distribution plants. The average prices of DEF 

distributed in containers are shown in Figure 2 below. Typically, the price of DEF was 

more expensive when sold in smaller volume containers and less expensive when sold 

in bulk containers.
5

Figure 2 – DEF Retail Pricing

Quantity 

(Gallon)

Cost Per

Quantity

Cost Per 

Gallon

1.0 $8.92 $8.92

2.0 $14.36 $7.18

2.5 $14.24 $5.70

5.0 $25.59 $5.12

55.0 $213.82 $3.89

275.0 $842.19 $3.06

2. Second Survey, August 2010

A second DEF availability survey was conducted August 2–11, 2010. ARB staff 

revisited potential suppliers of DEF that were part of the first survey. However, for this 

survey, greater focus was placed on truck stops and heavy-duty truck diesel refueling 

stations. As with the previous survey, DEF retailers listed on www.finddef.com and 

www.discoverdef.com were visited to see whether they had stocked DEF as advertised. 

In addition, staff returned to facilities surveyed previously that did not carry DEF but 

expressed intent to do so with increased demand. Less focus was placed on 

dealerships and automobile part stores. As you can see from the survey results in 

Figure 3 below, the availability of DEF increased slightly from the March survey period.
6

 

Figure 3 – DEF Survey – August 2010

3. Conclusion

Both surveys showed that DEF is readily available at major truck stop diesel refueling 

stations along major interstate highways (more than 90% availability as determined in 

the second survey). ARB staff understands that auto part stores, light/medium-duty 

vehicle diesel refueling stations, and major shopping retail stores do not typically carry 

DEF as part of their normal retail supplies. Nevertheless, over 30% of those businesses 

identified in the second survey sold DEF. 

Nearly all the 2010 MY HDD engines are equipped with the new SCR technology for 

controlling NOx emissions. These surveys were conducted within the first year of SCR 

implementation, and the penetration of these vehicles has not reached a significant 

portion of the full on-road HDD vehicle fleet. As older diesel vehicles are retired, the 

population of HDD trucks and passenger vehicles with SCR technology would increase 

and therefore, increase the demand and availability for DEF. ARB’s surveys show that 

DEF is currently being offered in an adequate supply to accommodate the limited 

number of vehicles operating on DEF. 

DEF Availability Survey Results 

August 2010

Have 

DEF

Available

No

DEF 

Available

DEF

To Be Sold 

Within 

6 Months

Total % Have 

DEF

% DEF To Be 

Sold Within 

6 Months

Known DEF 

Dealers* 23 2 0 25 92% 0%

Random Retail 

Facilities 127 300 36 427 30% 8%

* Includes diesel re-fueling stations and diesel repair facilities.
7

B. DEF Quality Tampering Survey

ARB staff conducted a different type of survey in September 2010. This survey's focus 

was to ascertain whether or not truck operators were using DEF and examine if there 

were any indications of SCR inducements occurring in use. The surveys were 

performed at seven California Highway Patrol commercial vehicle weigh stations in 

southern and northern California where ARB staff pulled over as many identifiable SCRequipped trucks as possible during the first two weeks of September. As part of the 

survey staff extracted a sample of DEF from each truck to measure urea concentration

to determine DEF quality. Staff also inspected the vehicles for DEF warning indicators, 

engine diagnostic lights, visually inspected emission control for tampering, and 

conducted a short driver’s questionnaire. Shown in Figure 4 below is an illustration of

the number of manufacturers’ vehicles that were inspected for the DEF Quality 

Tampering Survey.
8

Figure 4 – DEF Quality Tampering Survey – September 2010

Location Truck Cummins DDC Mack Volvo

Grand 

Total

Antelope Freightliner 1 1

Kenworth 3 3

Peterbilt 2 2

Banning Freightliner 2 2

Kenworth 2 2

Volvo 1 1

Castaic Freightliner 12 12

Kenworth 2 2

Peterbilt 4 4

Volvo 10 10

Conejo Freightliner 1 3 4

Kenworth 1 1

Peterbilt 3 3

Volvo 3 3

San Onofre N. B. Freightliner 2 2

Kenworth 3 3

Volvo 1 1

San Onofre S. B. Freightliner 2 1 3

Peterbilt 1 1

Volvo 3 3

Sidewinder W. B. Freightliner 1 1

Kenworth 1 1

Mack 1 1

Peterbilt 2 2

Volvo 1 1

Grand Total 28 21 1 19 69

N.B. – North Bound S.B. – South Bound W.B. – West Bound

1. DEF Quality Analysis

The DEF quality analysis involved taking a sample of DEF from each vehicle and testing 

it with a refractometer. A refractometer measures the refraction of light through a liquid 

to determine the refractive index of a sample. For this study, the refractive index of 

each sample taken from an inspected vehicle was compared to a high quality DEF 

(32.5% urea and 67.5% deionized water) baseline sample. The results of this analysis 

indicated that all 69 vehicles inspected had proper DEF in their tanks.
9

2. Driver Warning Indicators

As part of the visual inspection, ARB staff looked for driver warning and engine 

diagnostic lights. The visual inspection involved examining each vehicle’s instrument 

panel. No illuminated driver warning lights or engine diagnostic lights were found, 

indicating that the diagnostic systems detected no problems with the SCR or DEF 

dosing system.

3. Driver’s Questionnaire

Each vehicle operator was asked the following questions with a summary of their 

responses subsequently shown. 

• Question 1: Have you operated your truck without DEF? 

Response: One driver drove his truck for 10 miles without DEF. The remaining 

68 drivers indicated they had never run their truck without DEF.

• Question 2: Have you operated your truck on fluids other than DEF in the DEF 

tank?

Response: All 69 drivers stated they did not use any fluids other than DEF.

• Question 3: Have you had any problems with your truck’s emissions control 

system?

Response: All 69 drivers indicated that they have not experienced problems with 

their emissions control systems.

• Question 4: Have you had any problems locating DEF?

Response: 60 drivers had no problem locating DEF, while nine drivers indicated 

they had experienced problems. Of these nine drivers, four had problems 

locating DEF out-of-state and the other five had problems locating DEF in 

California (i.e., the owner could not purchase DEF at a particular diesel refueling 
10

station or the station had sold out of DEF). However, 68 drivers stated that they 

never ran out of DEF and only one driver indicated that he drove for only 10 

miles with an empty DEF tank.

4. Conclusion

The results of the survey indicated that drivers are using the proper DEF concentration 

(high quality) in their SCR-equipped vehicles. With the availability of DEF expected to 

increase in California and across the country, truck drivers are unlikely to be forced to 

operate without DEF due to unavailability. This type of inspection will be incorporated 

into ARB’s Heavy-Duty Vehicle Inspection Programs (HDVIP) in the future. 

C. Evaluation of SCR Driver Inducements

ARB procured three 2010 trucks that use SCR-equipped engines for more thorough 

evaluation. Before testing the vehicles, ARB staff examined the vehicle owner’s 

manuals and the February 2009 U.S. EPA Guidance to ascertain the expected 

inducement strategies for each vehicle in the ARB evaluation program. Typically, these 

include a sequence of visual and/or audible warnings on the instrument panel (e.g.,

warning lights, chimes, and/or text message displays) indicating DEF supply was low or 

a problem had been identified. As additional mileage is accumulated without remedying 

the problem or refilling the DEF supply, further driver inducements should occur, such 

as power de-rates or speed limits (which allow continued operation of the truck). 

Ultimately, if the problem is not corrected a severe inducement or final immobilization in 

the form of a no-start condition, or 5 mile per hour (mph) maximum speed limit, or an 

idle-only operation should be triggered once the vehicle reaches a safe harbor (e.g. 

when diesel refueling occurred, or the engine was turned off, or the vehicle was parked 

or idled for an extended period of time). The specific inducements for each engine 

evaluated are discussed below.

The evaluation focused on three vehicles with 2010 MY engines equipped with SCR 

systems. The vehicles evaluated included a 2011 Freightliner Cascadia equipped with 

a 2010 MY12.8 liter Detroit Diesel DD13 engine (Test Vehicle 1), a 2011 MY Kenworth 
11

T800 equipped with a 2010 MY 14.9 liter Cummins ISX15 engine (Test Vehicle 2), and 

a 2011 MY Dodge Cab Chassis D5500 equipped with a 2010 MY 6.7 liter Cummins ISB 

engine (Test Vehicle 3). Each vehicle was operated under the following test conditions 

to determine when driver inducements were initiated, how effective they were, how they 

compared to what was expected from reviewing the vehicle owner’s manuals, and 

consistency with the February 2009 U.S. EPA Guidance. 

• DEF Depletion Cycle –The vehicle would be operated until the DEF tank was 

depleted and the vehicle experienced a no-start condition, or 5 mile per hour (mph) 

maximum speed limit, or idle-only operation. According to the February 2009 U.S. 

EPA Guidance the following scenarios should occur. As DEF depletes, visual 

and/or audible alerts should warn the driver that the tank needed refilling. As DEF 

continues to deplete to empty, the driver may experience an engine power de-rate 

condition ranging between 25% to 40% depending on the vehicle type and DEF 

tank capacity. Typically, the first level inducement should begin at a 2.5% DEF 

level known as the DEF Trigger and should be in the form of either a 25% engine 

power de-rate or some maximum speed limit chosen by the manufacturer, and at 

that point the search for severe inducement should begin. The severe inducement 

or final immobilization should occur once a safe harbor event (diesel refuel, 

park/idle, engine restart) was reached any time after the 2.5% DEF Trigger. It is 

important to note that vehicle gauge levels may be calibrated to read lower than 

actual DEF tank level to build in reserve tank volume, e.g., 2.5% actual DEF level 

might read as 0% on the driver's gauge. Thus in some cases the DEF is still being 

injected into the SCR when the DEF gauge reads empty.

• DEF Contamination Cycle – The vehicle would be operated with water instead of 

DEF until the vehicle experienced a no-start condition, or 5 mile per hour (mph) 

maximum speed limit, or idle-only operation. According to the February 2009 U.S. 

EPA Guidance the following scenarios should occur. The detection of poor DEF 

quality should trigger initial visual and/or audible warnings. If no remedy occurred, 

an engine power de-rate should occur at 500 miles or 10 hours after initial 

detection, and a severe inducement or final immobilization should occur once a 
12

safe harbor event (diesel refuel, park/idle, engine restart) was reached following 

1,000 miles or 20 hours after the initial detection and warning. 

• DEF System Tampering Cycle – Following the disabling of the DEF system by 

ARB staff, the vehicle would be operated until it experienced a no-start condition,

or 5 mile per hour (mph) maximum speed limit, or idle-only operation. According to 

the February 2009 U.S. EPA Guidance, the following scenarios should occur. The 

detection of tampering should occur quickly depending on the particular tampering 

event triggering visual and/or audible warnings. If no remedy is sought, an initial 

25% engine torque power de-rate should occur at 500 miles or 10 hours after the 

initial detection, and a severe inducement or final immobilization should occur once 

a safe harbor event (diesel refuel, park/idle, engine restart) was reached following 

2,000 miles or 40 hours after initial detection and warning.

See Figure 5 for a summary of the February 2009 U.S. EPA Guidance consulted by 

ARB staff for the 2010 MY certifications and this test program. A copy of the test plan is 

attached in Appendix B. 

Figure 5 - FEBRUARY 2009 U.S. EPA GUIDANCE SUMMARY

DEF DEPLETION

INITIAL WARNING

• Visual or audible alarms which indicate low DEF level with escalation

• Unique symbol for DEF on dash that illuminates or message displayed

• Warnings cannot be defeated, ignored or turned off without additional DEF added

INDUCEMENTS

• Inducements begin before 2.5% DEF capacity triggering the "No-Engine Restart after Restart Countdown" 

or "No-Start after Refueling” or "No-Start after Parking" strategy. 

• Under these conditions the DEF indicator light will flash or a message shall be indicated on the Instrument 

Cluster (aka, "inducement notification"). This strategy will lead to the "DEF Trigger" inducement. 

SEVERE INDUCEMENT

• At “DEF Trigger” (2.5% DEF) or at DEF Empty for 1:1 DEF/Fuel Tank Size

o 25% torque de-rate for DEF Trigger or 40% for 1:1 DEF/Fuel Tank Size

o Search for Severe Inducement 5 mph speed limit (one of 3)

 Disable after fueling

 Disable after Parking (>1 hr or 10-20 minutes after 24 hr operation)

 Disable after restart
13

Figure 5 - FEBRUARY 2009 U.S. EPA GUIDANCE SUMMARY - continued

DEF CONTAMINATION

INITIAL WARNING

• Once Detected: Warning message or light

INDUCEMENTS

• At detection + 500 miles or 10 hrs 

o 25% torque de-rate

o Under these conditions the DEF indicator light will flash or a message shall be indicated on the 

Instrument Cluster 

SEVERE INDUCEMENT

• At detection + 1,000 miles or 20 hrs 

o 25% torque de-rate continues

o Search for Severe Inducement 5 mph speed limit (one of 3)

 Disable after fueling

 Disable after Parking (>1 hr or 10-20 minutes after 24 hr operation)

 Disable after restart

DEF SYSTEM TAMPERING CYCLE

INITIAL WARNING

• Once Detected: Warning message or light

INDUCEMENTS

• At detection + 500 miles or 10 hrs 

o 25% torque de-rate

o Under these conditions the DEF indicator light will flash or a message shall be indicated on the 

Instrument Cluster 

SEVERE INDUCEMENT

• At detection + 2,000 miles or 40 hrs 

o 25% torque de-rate

• Severe Inducement 5 mph speed limit (one of 3)

o Disable after fueling

o Disable after Parking (>1 hr or 10-20 minutes after 24 hr operation)

o Disable after restart
14

Driving routes were selected to represent a broad range of engine loading. Each test 

vehicle’s engine load was expected to vary from nearly full power conditions, when 

hauling heavy loads uphill, to a near zero engine load when traveling downhill. ARB 

staff also compared the driver inducements to what was provided in the February 2009 

U.S. EPA Guidance for each of the test conditions listed above, as well as, the vehicle 

owner’s manuals and engine service manuals. It was expected that each condition 

described above would result in staged driver warnings in the form of a DEF level 

indicator, messages in the instrument cluster, a low DEF light indicator, stop engine 

light, and/or audible warnings. If warnings were ignored and remedies were not applied 

as mileage accumulated, further driver inducements would be initiated in the form of 

engine power de-rating, or speed limiting. Ultimately, a severe inducement would 

require the vehicle to be immobilized by limiting speed to 5 mph, or restricting engine 

operation to an idle-only or a no-start condition. 
15

1. Test Vehicle 1 

Chassis: 2011 MY Freightliner 

Cascadia

Axles: 3

Engine: Detroit Diesel Corporation

Engine Family: ADDXH12.8FED

Displacement: 12.8 Liter

Horsepower: 470

Trailer: 48-foot flatbed 

Test Vehicle 1 was a 2011 MY Freightliner Cascadia equipped with a 2010 MY Detroit 

Diesel Corporation (DDC) DD13 engine rented from a local Penske Truck Rental. 

When ARB took possession of the vehicle from Penske, the odometer showed 361

miles. The vehicle towed a 48-foot flatbed trailer and was loaded with five 20-foot “Krail” concrete barriers that weighed about 40,000 pounds.

Figure 6, shown on the next page, (reproduced with DDC’s permission and referenced 

in part from their engine service manual) describes the expected driver warnings and 

inducements, the corresponding system response, and the associated dashboard 

gauge/light combinations. The first driver warning was expected to occur during the 

DEF Depletion Cycle when the vehicle’s DEF level fell below 10% of its capacity (see 

Step 1, Figure 6). As the DEF level depleted below 5%, the driver should be subjected 

to specific combinations of illuminated gauge/light combinations (Steps 2 through 4, 

Figure 6), including an engine power de-rate, and limiting vehicle speed to 55 miles per 

hour (mph). If the DEF was not refilled and the vehicle reached a safe harbor event 

(i.e., the vehicle was re-fueled, or the engine was turned off and restarted, or after 350 

gallons of diesel fuel had been consumed since the DEF tank empty warning alert), a

severe inducement limiting vehicle speed to 5 mph should be initiated. The SCR 

system was expected to trigger similar driver warnings and inducements during the DEF 

Contamination Cycle and the DEF System Tampering Cycle, but at different 
16

mileage/hour triggers after detection of poor quality DEF or tampering consistent with 

the February 2009 U.S. EPA Guidance Summary in Figure 5. 

Figure 6 - DDC's DEF Fluid Level Warning Lights

a) DEF Depletion Cycle

In preparation for the DEF Depletion Cycle staff adjusted the truck’s DEF level to 

illuminate one green square on the DEF level gauge (odometer = 841 miles). After 

driving 14 miles to a diesel refueling station, the truck’s diesel fuel level was then filled 

to 75% of capacity indicated by the diesel fuel level gauge (odometer = 855 miles). 

Driving 185 more miles after diesel refueling (odometer = 1,040 miles), the first driver

warning occurred by illuminating the DEF gauge’s solid amber circle and one solid 

amber square (see Step 1, Figure 6).
17

The SCR system escalated the driver warning sequence 77 miles after the initial 

warnings (odometer = 1,117 miles) with a flashing amber circle and a flashing red 

square on the DEF gauge, as well as illuminating the amber text check engine light. In 

conjunction with these visual warnings, the first vehicle inducement occurred when the 

driver noticed the vehicle speed was limited to about 55 mph, as described in the 

engine service manual. The driver experienced an engine power de-rate when 

negotiating a steep grade 33 miles (odometer = 1,150 miles) after the 55 mph limiter 

was triggered (see Step 2, Figure 6).

The engine manufacturer diagnostic (EMD) malfunction indicator light (MIL) flashed 

periodically and after accumulating 233 miles (odometer = 1,383 miles) the MIL stayed 

on continuously. At this time, the DEF gauge’s amber circle and red square continued

flashing, and the amber text check engine light remained illuminated (see Step 3, 

Figure 6). The vehicle continued to experience an engine power de-rate and a 

maximum vehicle speed limited to about 55 mph. 

After driving another 40 miles since the EMD MIL illumination (odometer = 1,423 miles)

(see Step 3, Figure 6), staff stopped to refuel the vehicle and turned off the engine. 

Upon adding 57.8 gallons of diesel fuel to the vehicle and restarting the engine, the final 

driver warnings occurred. This warning series included the DEF gauge’s flashing amber 

circle and a flashing red square on the DEF level gauge, the illumination of the amber 

text check engine light, the illumination of the amber EMD MIL, and the illumination of 

the red text stop engine light. As staff attempted to exit the diesel refueling station, staff 

immediately experienced the 5 mph severe inducement condition (see Step 4, 

Figure 6). 

With the SCR system limiting the vehicle speed to 5 mph, the final step of the DEF 

Depletion Cycle had occurred (odometer = 1,423 miles). Staff drove the vehicle out of 

the way of other station traffic and shut down the vehicle. 
18

b) DEF Contamination Cycle 

To begin the DEF Contamination Cycle, about three gallons of water were added to the 

DEF tank prior to engine startup. After starting the engine, staff observed that all the 

various illuminated dashboard warning lights that were previously active, were now off 

as the SCR system had reset, and one solid green square was illuminated on the DEF 

gauge. As staff began to drive the vehicle, they also noticed the vehicle was no longer 

experiencing any engine power de-rate and seemed to drive normal. The odometer 

was at 1,424 miles as the test route was resumed.

The SCR system triggered the first driver warning and inducement for contaminated 

DEF after driving 41 miles (odometer = 1,465 miles) with the illumination of the DEF 

gauge’s flashing amber circle, the amber text check engine light, and the amber EMD 

MIL (similar to Step 3, Figure 6). Note: the red square was not flashing (one green bar 

was illuminated). Over the next 345 miles (odometer = 1,810 miles) the first set of 

driver warnings as listed above remained illuminated, and at this point the vehicle 

initiated the inducements of an engine power de-rate and the 55 mph speed limiter as 

noticed by the driver.

The operator continued driving the vehicle for several days accumulating an additional 

504 miles (odometer = 2,314 miles) before having to refuel the vehicle. While 

accumulating these miles, the SCR system maintained the driver warnings illuminating 

the DEF gauge’s flashing amber circle, the amber text check engine light, the amber 

EMD MIL and continued the engine power de-rate and 55 mph speed limiter. Upon 

adding 101 gallons of diesel fuel to the vehicle and restarting the vehicle, the SCR 

system continued all previous visual warnings and illuminated a new red text stop 

engine light (similar to Step 4, Figure 6). The vehicle immediately experienced the 5 

mph limited speed event. With the SCR system limiting the vehicle speed to 5 mph, the 

final step of the DEF Contamination Cycle had occurred (odometer = 2,314 miles).

In preparation for the next test cycle, ARB staff completely siphoned the water out of the 

DEF tank and refilled it with approximately twelve and a half gallons of DEF. The 

vehicle continued to experience the 5 mph speed limiter severe inducement along with 
19

the illuminated visual warnings leaving the driver stranded. With the inducement 

occurring next to a repair center, staff proceeded to drive to this location with the 5 mph 

limited speed condition. Although the technician attempted to clear the codes with a 

standard scan tool, he was unsuccessful. The technician stated that he could make the 

repair with another scan tool but ARB would be charged for this service. ARB staff 

called the Penske Truck Rental office for assistance, and Penske authorized the repair. 

Within 30 minutes, and after utilizing an advanced scan tool, the technician reset the 

engine control unit (ECU) removing all inducement conditions. ARB staff was charged 

$240 by Penske for this service call. Staff drove the vehicle for 20 miles to ensure the 

vehicle returned to its normal operation (odometer = 2,334 miles). 

c) DEF System Tampering Cycle

Test Vehicle 1 was prepared for testing by unplugging the DEF Injection Pump electrical 

connector (odometer = 2,334 miles). After startup, the SCR system immediately 

triggered the driver warnings illuminating the amber text check engine light and the 

amber EMD MIL (similar to Step 3, Figure 6), and after driving 56 miles, an apparent 

engine power de-rate occurred (odometer = 2,390 miles). Staff continued to drive for 

another 160 miles (odometer = 2,550 miles) but did not experience any additional 

inducement conditions. Unfortunately, due to contractual obligations, ARB staff had to 

terminate testing and was unable to complete the final stages of inducements for this 

test cycle.

d) Vehicle 1’s Inducement Test Summary

ARB staff operated Test Vehicle 1 under various test cycles comparing the vehicle’s 

SCR-related driver warnings and inducements to those supplied in the vehicle owner’s 

and engine service manuals and their consistency with the February 2009 U.S. EPA’s 

Guidance. ARB staff checked the driver warnings and inducements under the following 

conditions: DEF Depletion Cycle, DEF Contamination Cycle, and DEF System 

Tampering Cycle. Under the DEF Depletion Cycle, this vehicle performed as expected 

inducing visual warnings that were preceded by escalating lower DEF level 

inducements: an engine power reduction, a maximum vehicle speed limited to 55 mph 
20

and ultimately a 5 mph limited vehicle speed inducement. All prescribed inducement 

strategies appeared consistent with the February 2009 U.S. EPA Guidance of a 2.5% 

DEF Trigger to search for severe inducement with an engine power de-rate. 

The DEF Contamination Cycle performed similar to the DEF Depletion Cycle prompting 

escalating low DEF level warnings and inducements including an engine power 

reduction and a 55 mph speed limiter, well within the U.S. EPA’s 500 mile guidance and 

finally induced a severe 5 mph limited vehicle speed event that was within the U.S.

EPA’s 1,000 mile search for severe inducement guidance. 

Under the DEF System Tampering Cycle the vehicle was consistent with the U.S. EPA’s

500 mile preliminary inducement guidance (i.e., the vehicle invoked visual warnings and 

an engine power de-rate) but due to time constraints, ARB staff had to end this 

program early and did not complete the final stages of inducements for this test cycle.

Regarding the effectiveness of the inducement strategies, ARB staff reported that visual 

warnings were effective in drawing the driver’s attention to the need for SCR-related 

service. Also, driving this vehicle once the initial inducement occurred (engine power 

de-rate and 55 mile per hour speed limit) was neither acceptable nor tolerable when 

trying to accelerate or driving uphill, and would likely cause a driver to refill with DEF or 

correct the SCR problem. In addition, once the vehicle entered into a 5 mph limited 

speed condition under a DEF contamination event, the only way to resume normal 

operation was to have the vehicle serviced, drain water out of the system and refill the 

vehicle with DEF, followed by a reset of the system by an authorized service technician; 

therefore, the driver would be stranded until proper servicing. The ARB staff concludes 

the inducements were effective for this vehicle because the constant inducement 

strategies and risk of costly repairs were not worth the lost time and financial business 

losses when DEF could simply be added to ensure proper vehicle operation.
21

2. Test Vehicle 2

Chassis: 2011 MY Kenworth T800

Axles: 3

Engine: Cummins ISX15

Engine Family: ACEXH0912XAP

Displacement: 14.9 Liter

Horsepower: 450

Trailer: 45-foot Curtain Trailer

Test Vehicle 2 was a 2011 MY Kenworth T800 equipped with a 2010 MY Cummins 

ISX15 450 engine that was procured in July 2010 by ARB. When ARB took possession 

of the vehicle from the dealer/owner, the odometer showed 457 miles. The vehicle 

towed a 45-foot curtain trailer and carried five 20-foot “K-rail” concrete barriers that 

weighed about 40,000 pounds. 

Figure 7, shown on the next page, describes the expected driver warnings and 

inducements by showing the specific dashboard lights and warnings, as well as the 

expected vehicle inducements, triggered by the SCR system (see Stages 1 through 4, 

Figure 7). This chart was created by ARB staff as an interpretation of the inducements

specified in the vehicle owner’s manual. The first driver warning was expected to be 

triggered when the truck’s DEF level drops below 1/8 of tank capacity during the DEF 

Depletion Cycle (see Stage 1, Figure 7). As DEF was depleted, the driver should be 

subjected to additional warnings as indicated in Stage 2 (below 1/8 tank but above 

empty - DEF level). When the DEF level is close to empty, the additional inducements 

should include a check engine light illumination and an engine torque de-rate (see 

Stage 3, Figure 7). Ultimately, when the DEF gauge reads empty and the vehicle is 

turned off or idled for 20 hours the vehicle should enter a 5 mph speed limited condition

accompanied by a stop engine light (see Stage 4, Figure 7). The SCR system should 

trigger similar driver warnings and inducements during the DEF Contamination Cycle 
22

and the DEF System Tampering Cycle but at different mileage/hour trigger points as 

shown in Figure 7, Stage 1a through 3a.

Figure 7 - Cummins Driver Warnings and Inducements 

STAGE 2

Below 1/8th tank but above empty

STAGE 1

~10% DEF or 1/8TH of TANK SOLID

DEF TANK LEVEL

LAMP INDUCEMENT

NOTIFICATION

FLASHING

FLASHING

KEY: LOW DEF 

MESSAGE

DEF GAUGE 

ALERT

CHECK ENGINE 

LIGHT

STOP ENGINE 

LAMP

STAGE 3

Tank close to empty

STAGE 4

Tank is empty

After the engine has been turned off or 

prolong idle. FLASHING

OBD MIL

ENGINE DERATE 

MESSAGE

DEF DEPLETION

DEF QUALITY OR TAMPERING

STAGE 1a

Problem Detected

STAGE 2a

10 hrs or 500 mi after detection

STAGE 3a

20 hrs/1,000 mi after detection (Quality)

40 hrs/2,000 mi after detection (Tampering)

SOLID

FLASHING

FLASHING

- 5 mph speed after keyoff/restart or,

- Engine Idles for 20 hrs
23

a) DEF Depletion Cycle

Staff adjusted the vehicle’s DEF level to roughly 20% of full capacity as indicated by the 

DEF level gauge on the vehicle’s dash panel (see Figure 8, ≈ 20% DEF Tank Level). 

The cycle began with 457 miles on the odometer. After driving 113 miles (odometer =

570 miles) staff stopped to fill the diesel fuel tank to approximately 75% of full capacity 

as indicated by the vehicle’s fuel level gauge.

Figure 8 - Cummins Driver Panel DEF Level Gauge

≈ 20% DEF Tank Level

The first low DEF driver warning occurred when the DEF gauge level fell below 1/8th of 

a tank accompanied by a solid red DEF gauge light (see Stage 1, Figure 7) 115 miles 

after the diesel fueling (odometer = 685 miles). Additionally, the Driver Information 

Center (DIC) displayed the message “Low Diesel Exhaust Fluid” (see Figure 9). 

Figure 9 - Driver Information Center Low DEF Message
24

After driving an additional 44 miles (odometer = 729 miles), the red DEF gauge light 

began to flash (see Stage 2, Figure 7). When the DEF gauge reached empty 24 miles 

later (odometer = 753 miles), the check engine light illuminated, and was followed in 

another 130 miles by an engine torque reduction as experienced by the driver 

(odometer = 883 miles). The driver commented that the vehicle labored through gears 

and perceived an engine power de-rate when driving on uphill grades. The driver also 

noted there seemed to be de-rate fluctuations as he continued to operate the vehicle

under various driving conditions. 

Even after driving an additional 559 miles (odometer = 1,442 miles) after encountering 

an engine torque de-rate, repeated key-on/key-off events did not trigger the 5 mph 

inducement. This officially terminated this test cycle. 

While the vehicle’s early warning and first level inducements were consistent with the 

February 2009 U.S. EPA Guidance, the severe inducement never occurred. Over the 

next 124 miles staff investigated the reasons why the vehicle would not enter its severe

inducement and found that approximately one quart of DEF remained the DEF tank; 

therefore the vehicle never triggered the zero DEF inducement. Staff removed the 

residual DEF from the tank and started the vehicle which was immediately limited to 5 

mph. ARB staff believed the truck would not have entered the 5 mph speed limited 

condition if the final quart of DEF was not pumped out of the tank. It should be noted 

since taking delivery of this vehicle from the dealer, the on-board diagnostic (OBD) MIL 

and the stop engine light intermittently illuminated that was later determined to be 

related to a throttle position sensor problem. The engine de-rate condition as a result of 

the throttle position sensor problem was different than the SCR inducement engine derate because the OBD MIL and de-rate event could be quickly cleared by snapping the 

accelerator throttle. 

b) DEF Contamination Cycle 

Staff prepared for this test cycle by completely filling the DEF tank with water and the 

diesel fuel tank with diesel fuel. With the odometer reading 1,567 miles, testing 
25

commenced and staff began operating the vehicle over the designated test route. After 

57 miles of operation (odometer = 1,624 miles) the SCR system had restored engine 

power to normal, as well as, turned off the dashboard warning lights that were attained 

during the DEF Depletion Cycle. The first driver warning occurred 582 miles since the 

SCR system restored itself back to normal operation (odometer = 2,206 miles) and 

illuminated the OBD MIL. After driving another 225 miles (odometer = 2,431), the OBD

MIL continued to illuminate and the driver experienced an engine power de-rate 

condition. Although the engine power was de-rated, the vehicle continued to operate 

satisfactorily on flat surfaces (less acceptable on steeper grades). The engine 

appeared to intermittently de-rate as felt by the driver, and the red stop engine light

illuminated at times, as staff continued to drive another 686 miles (odometer = 3,117). 

Staff decided to terminate the cycle after a total of 1,550 miles had been accumulated 

for this cycle (i.e., 911 miles had been driven and more than 30 hours had elapsed) 

since the first driver warning occurred. This was accompanied by several key-off/restart

events due to the intermittent nature of the warning and inducements. The results of 

the DEF Contamination Cycle inducement strategies were inconsistent with the vehicle 

owner’s manual and the February 2009 U.S. EPA Guidance.

After the DEF gauge read near empty, staff added DEF several times over the next 143

miles (odometer = 3,260 miles) until the DEF gauge read almost full, yet staff was 

unable to clear the OBD MIL or engine power de-rate conditions. The vehicle was 

taken to a Cummins dealer, who in their investigation of the problem confirmed the DEF 

tank was contaminated with water using a refractometer and declined any warranty 

coverage for the repair, which was verbally estimated to be $800. The repair would 

involve removing and flushing the system with DEF fluid and reinstalling the 

components. ARB declined the service, but requested that the dealer reset the 

computer and clear any trouble codes which cost $125. Cummins’ proprietary 

equipment was used to communicate with the vehicle’s electronic control module (ECM)

to reset the system clearing the DTCs. ARB staff returned the vehicle to ARB’s 

Stockton facility and flushed the DEF system (i.e., the DEF tank and associated hoses) 

with DEF. 
26

Following the DEF system flush, staff drove the vehicle to a Kenworth dealer to have 

the ongoing throttle position sensor problem repaired. The dealer provided warranty 

replacement of the defective throttle position sensor. Although the throttle position 

sensor was problematic, the vehicle should have entered into the 5 mph severe 

inducement condition, yet failed to do so. However, staff later learned that Cummins 

instituted a voluntary recall plan (Cummins Campaign C1036) to recalibrate the ECM 

which corrected the failure to initiate the 5 mph severe inducement. 

c) DEF System Tampering Cycle

After repairs were performed and the vehicle appeared to operate normally, staff began

the DEF System Tampering Cycle by disabling Test Vehicle 2’s DEF doser valve 

(odometer = 3,487 miles). The first driver warning occurred at initial engine start up with 

an OBD MIL illumination. After accumulating 97 miles (odometer = 3,584 miles), the 

vehicle’s DEF warning light was flashing, the OBD MIL and check engine lights were 

illuminated, the engine went into an engine power de-rate (see Stage 2a, Figure 7) and 

the driver display indicated “Low Diesel Exhaust Fluid” (see Figure 9).

Figure 10 - Driver Information Center Engine De-rated Message

The driver subsequently discovered at 3,991 miles shown on the odometer that the DIC 

would display the message “Engine De-rated” (see Figure 10). Unfortunately, this 

message doesn’t display automatically as the vehicle de-rates; the driver must initiate 

the message by manually changing the DIC display. Staff continued to drive the vehicle 

for more than 2,500 miles and more than 48 hours with multiple key-off/restarts events 
27

after the engine de-rated for this test cycle (odometer = 6,136 miles). However, as with 

the DEF Contamination Cycle the 5 mph speed limit did not occur. The DEF System 

Tampering Cycle inducement strategies were inconsistent with the vehicle owner’s 

manual and the February 2009 U.S. EPA Guidance. 

d) Vehicle 2’s Inducement Test Summary

ARB staff operated Test Vehicle 2 comparing the vehicle’s SCR-related driver warnings 

and inducements to those strategies stated in the February 2009 U.S. EPA Guidance

and the expected SCR inducement conditions as laid out in the vehicle owner's manual. 

ARB staff checked the driver warnings and inducements triggered by the SCR system 

during the following cycles: DEF Depletion Cycle, DEF Contamination Cycle, and DEF 

System Tampering Cycle. Under the DEF Depletion Cycle, this vehicle initiated the 

visual warnings, induced the engine power de-rate sequence, but failed to enter into the 

5 mph severe vehicle speed inducement condition after traveling 757 miles from the first

driver warning detection point. Staff did force the 5 mph limited speed inducement 

condition by removing the last quart of DEF from the tank. 

The DEF Contamination Cycle raised concerns as it took over 639 total miles to detect 

the addition of water in place of DEF. In addition, while the engine power reduction 

seemed to occur well within the U.S. EPA’s 500 mile after detection guidance, the derate inducement and warnings were intermittent. After multiple key-off/restart events

and intermittent first level inducements, staff determined the vehicle was inconsistent 

with the February 2009 U.S. EPA Guidance and terminated the cycle. 

Under the DEF System Tampering Cycle, the vehicle prompted escalating warnings 

including an engine power reduction well within the U.S. EPA 500 mile guidance. 

However, after traveling more than 48 hours and 2,649 miles, the vehicle failed to enter 

into a severe 5 mph speed limited inducement despite several key-off/restart events 

which is outside of the U.S. EPA 40 hour or 2,000 mile guidance.

Midway through staff’s vehicle testing, staff discovered that Cummins was already 

aware of the failure to reach severe inducement and had made production line 
28

programming changes in the second quarter of 2010. They also followed up with a 

voluntary recall (Cummins Campaign C1036) in August of 2010 to correct in-use 

engines. A voluntary recall is an inspection, repair, adjustment, or modification program 

voluntarily initiated and conducted by a manufacturer or its agent or representative to 

remedy any vehicle issue in which direct notification of the vehicle or engine owners is 

necessary. The campaign included the recalibration of the ECM to correct SCR 

inducement strategies concerning DEF depletion and DEF quality for their 2010 MY

engines. However, staff elected not to apply the recall to their test vehicle until the 

completion of its testing period to avoid an interruption of its testing process. Since 

completing the original test program, the Cummins 14.9L engine has been reflashed 

with the Cummins’ recall fix and ARB staff is currently re-evaluating these cycles. 

Regarding the effectiveness of the inducements for this vehicle, ARB staff reported that 

visual warnings were effective in drawing the driver’s attention to the need for DEF 

service. However, since the throttle position sensor was suspected of causing engine 

power fluctuations during the DEF Depletion and Contamination Cycles, staff could not 

objectively rate the effectiveness of the engine power de-rate under those cycles 

because it was not clear if de-rate occurred because of a detected SCR problem or was 

the result of the defective throttle position sensor. However, even after the throttle 

position sensor was repaired, the engine power de-rate caused the vehicle to lose 

power and reduce vehicle speed when negotiating uphill or accelerating, but was 

seldom noticed when driving on level ground. The drivers reported that the Cummins 

engine power de-rate was not as noticeable as the DDC vehicle engine power de-rate 

at similar power and engine speeds.
29

3. Test Vehicle 3

Chassis: 2011 MY Dodge

 Cab Chassis D5500

Axles: 2

Engine: Cummins ISB

Engine Family: ACEXH0408BAL

Displacement 6.7 Liter

Horsepower: 305

Test Vehicle 3 was a 2011 MY Dodge Cab Chassis D5500 incomplete vehicle equipped 

with the 2010 MY Cummins ISB 305 engine rented from a local Southern California 

Dodge dealer. When ARB took possession of the vehicle, the Dodge dealer outfitted 

the vehicle with a flatbed platform with 15 miles showing on the odometer. To add 

weight to the vehicle, the vehicle was loaded with a single 10-foot “K-rail” concrete 

barrier that weighed about 4,000 pounds. To determine the impact on NOx emissions,

this truck was outfitted with a Sensors, Inc. Semtech-DS PEMS unit allowing for realtime emissions readings as the vehicle was operated through the DEF Depletion Cycle, 

DEF Contamination Cycle, and DEF System Tampering Cycle. 

The driver warnings and inducements included various displays on the Electronic 

Vehicle Information Center (EVIC) prominently located in the center of the instrument 

panel (see Figure 11). This was the only vehicle tested by ARB that had both audible

alerts and visual warnings. Figure 12 shown below, was created by ARB staff as an 

interpretation of the SCR inducement sequences for this vehicle based on the 

information provided in the vehicle owner’s manual. As indicated in the vehicle owner’s 

manual, the first DEF Depletion inducement in the form of warning messages (as shown 

in Figure 12) and chimes should occur when approximately 1,000 miles of driving 

remains until DEF runs out. If DEF still has not been added 500 miles after the initial 

warnings occurred, the vehicle should enter into a 500 mile countdown sequence as 

indicated on the dash mounted display. Once the display reaches zero miles and no 

DEF has been added to the vehicle’s DEF tank, the vehicle should not start upon its 

next key-off/key-on event. Similarly, during the DEF Contamination and DEF 
30

Tampering Cycles the 500 mile countdown sequence should begin if no remedy is 

sought after operating 250 miles with warnings and chimes, versus 500 miles for DEF 

Depletion. NOTE: For monitoring Test Vehicle 3 inducement mileage information, the 

inducement segments were tracked using the vehicle’s trip odometer. 

a) DEF Depletion Cycle

Testing began with an 18% tank capacity of DEF and a full tank of diesel fuel with zero 

miles indicated on the trip odometer (Note: the EVIC can display the DEF level capacity 

in percentage as shown in Figure 11). The vehicle was operated over the test route and 

the baseline emissions of the vehicle were established (i.e., the measured emissions of 

the vehicle while operating on appropriate DEF and no tampering).

Figure 11 – Electronic Vehicle Information Center

After 53.8 miles of operation, as the DEF was being consumed, the first driver warning 

took place when the DEF level gauge reached 16% of full capacity. The EVIC 

displayed the message “Low DEF Refill Soon” and then extinguished (see Stage 1, 

Figure 12 below). This message reappeared during vehicle start up and about every 50 

miles accompanied by an audible chime for about the first 100 miles and decreased to

approximately 50 mile intervals as the DEF became increasingly empty. After 195 miles 

of operation since beginning this cycle (trip odometer = 195 miles), staff noticed that the 

EMD MIL illuminated and subsequently extinguished (Note: the EMD MIL illuminated 
31

due to the DEF heater circuit problem discussed below) before any other messages or 

inducements occurred. When the trip odometer reached 934 miles, the DEF gauge 

level read 0%, the EMD MIL was illuminated again and remained on this time, and the 

EVIC displayed the message “Refill DEF Engine Will Not Restart in 500 Miles” (see 

Stage 2, Figure 12) initiating the 500 mile countdown. For the duration of the 500 mile 

countdown, the EVIC message was continuously displayed to the driver and was 

accompanied with a chime alert approximately every 50 miles decreasing to about 

every 25 miles and then to about every 10 miles. Staff continued to drive the vehicle 

route and accumulated 97 miles (trip odometer = 1,031 miles) since the 500 mile 

countdown initiated and stopped for the night. The following morning at the next key 

start, the DEF level gauge read 1%, cancelling the 500 mile counter and displayed the 

message, “Low DEF Refill Soon.” Staff was unclear as to why the counter reset and will 

discuss this issue with Cummins to obtain more information regarding this concern. 

After the morning restart, staff accumulated another 35 miles on the vehicle (trip 

odometer = 1,066 miles) and the no-start counter reinitiated the 500 mile countdown. 

After driving 497 miles since the countdown had initiated the second time, the EVIC 

message displayed “Refill DEF Engine Will Not Start” (see Stage 3, Figure 11). Staff 

drove for seven more miles with the audible chime sounding about every two minutes, 

and the EMD MIL illuminating continuously, and then executed a key-off/restart event. 

The vehicle did not start (trip odometer = 1,570 miles). 

Staff later determined that the vehicle had a DTC 205B-DEF heater malfunction. A DEF 

heater is used to prevent DEF from freezing during very cold weather operation; under 

normal weather conditions, the DEF heater is not used. If the DEF temperature 

becomes too hot, the DEF can degrade and become less effective at reducing NOx 

levels in the SCR catalyst. The DEF is heated during cold temperature situations by the 

flow of engine coolant passing through coolant tubes in the DEF tank. Based on the 

PEMS emission results, rate of DEF consumption and subsequent discussions with 

Cummins on their DEF heater issue, staff has deduced that the DEF heater was 

malfunctioning during this cycle. It is suspected on return trips to El Monte from Baker 

under elevated afternoon ambient temperatures, a DEF engine coolant control valve 
32

was not able to completely shut the flow of engine coolant passing through the coolant 

tubes in the DEF tank. This allowed the DEF temperature to rise above its normal 

operating range and caused the vehicle to stop dosing DEF. Staff did find out during 

their discussions with the manufacturer, that Cummins was addressing this problem and 

launched a service campaign (Technical Service Bulletin No. 25-002-10) through 

Chrysler’s Dodge dealer network. The Technical Service Bulletin stated that some 

Dodge trucks may have been built with a DEF engine coolant control valve that may be 

internally misassembled causing the overheated DEF problem. Due to this issue, the 

vehicle was driven nearly twice as far (i.e., 880 miles vs 500 miles) to reach the next 

phase of inducements because the SCR system was dosing DEF about half of the time. 

While the vehicle was, in general, consistent with the intentions of the February 2009 

U.S. EPA Guidance, the mileage accumulation was too high for the appropriate DEF 

consumption rate expected; however, this was related to the DEF heater glitch (i.e., 

DEF engine coolant control valve) as described above.
33

Figure 12 – Cummins’ 6.7L SCR System Warning Sequence

+

+

STAGE 1

• The EVIC message will be displayed at every startup for a short period; while driving, the message will display 

periodically increasing in frequency as the vehicle is continually driven on low DEF; if incorrect reducing agent/

tampering is also detected, the “Service DEF System – See Dealer” message will appear.

• The chime will accompany the EVIC message at every startup; while driving, the chime will sound periodically 

increasing in frequency. 

STAGE 2 

• The EVIC message will be displayed continuously (with actual mileage countdown from 500 miles); if incorrect 

reducing agent/tampering is also detected, the vehicle will operate under Stage 1 for 250 miles then initiate the 

500 mile countdown message. 

• The chime will sound periodically increasing in frequency as the vehicle is continually driven.

STAGE 3

• The EVIC message will be displayed continuously. If incorrect reducing agent/tampering is also detected, the 

“Service DEF System Engine Will Not Start – See Dealer” message will appear. 

• The chime will sound periodically.

• The DEF icon will display continuously, independent of the EVIC message

Periodic Chime

STAGE 1 

MESSAGE:

LOW DEF 

REFILL SOON

STAGE 2 

MESSAGE:

REFILL DEF 

ENGINE WILL 

NOT RESTART 

IN XXX MILES

STAGE 3 

MESSAGE:

REFILL DEF 

ENGINE WILL 

NOT START

First Warning 

Begins When 

DEF Level 

Reaches a 

Driving Range 

of 1,000 Miles

Single Chime During 

Vehicle Start Up

+

Periodic Chime
34

b) DEF Contamination Cycle

To initiate the DEF Contamination Cycle, the DEF tank was filled with water, which 

cleared the no start condition. This cycle began with 1,574 miles on the trip odometer. 

The vehicle was operated for 12 miles (trip odometer = 1,586 miles) over the designated 

test route when the SCR system detected contaminated DEF and displayed the EVIC 

message “Service DEF System – See Dealer” and the EMD MIL illuminated on the 

vehicle instrument panel (see Stage 1, Figure 12). The vehicle was operated for 249 

additional miles passed the first warning message (trip odometer = 1,835 miles) until the 

EVIC message changed to “Service DEF System Engine Will Not Start In 500 Miles -

See Dealer” and was accompanied by an audible chime (see Stage 2, Figure 12). The 

EMD MIL remained illuminated and the audible chime sounded in an increased 

frequency during the 500 mile countdown. Staff continued to drive the vehicle for 497 

miles (trip odometer = 2,332 miles) trip and the countdown expired at zero miles. When 

the counter reached zero, the EVIC message displayed “Service DEF System Engine 

Will Not Start – See Dealer” (see Stage 3, Figure 12), still accompanied by an 

illuminated EMD MIL. As staff continued to drive for six more miles (trip odometer = 

2,338 miles), the message was also accompanied by an audible chime about every 2 

minutes. Staff stopped the vehicle and turned off the engine. Attempts to restart the 

vehicle failed. The vehicle inducement strategies were consistent with the February 

2009 U.S. EPA Guidance and vehicle owner’s manual. 

Following this no-start condition, staff used a Mastertech OBD scan tool to review the 

stored DTC information and then cleared the trouble codes. The following is a list of 

stored DTCs: P205B-Reductant Tank Temp Sensor Circuit, P20EE-SCR NOx Cat 

Efficiency Below Threshold, and P207F-Reductant Quality Poor. With the stored 

trouble codes removed, and the EVIC warning message and illuminated EMD MIL

turned off, staff noted the vehicle started and returned to normal operation. This 

completed the DEF Contamination Cycle.
35

c) DEF System Tampering Cycle

In order to initiate the DEF System Tampering cycle, staff drained the water from the 

DEF tank, filled the tank with appropriate DEF, cleared the diagnostic trouble codes and 

the no-start condition using a scan tool, and disconnected the DEF doser injector to 

represent tampering. At start up with trip odometer at 2,376 miles, the vehicle 

immediately set an EMD MIL and audible chime and the EVIC displayed the message 

“Service DEF System - See Dealer”. The vehicle was operated for 250 miles (trip 

odometer = 2,626 miles) after disconnecting the DEF doser injector at which time the

EVIC display changed to “Service DEF System Engine Will Not Start In 500 Miles – See 

Dealer” (see Stage 2, Figure 12), accompanied by an illuminated EMD MIL. As staff 

continued to drive the vehicle, an audible chime sounded in an increased frequency 

during the 500 mile countdown and the EMD MIL continued to illuminate. The 

countdown expired after accumulating 496 miles (trip odometer = 3,122 miles) triggering 

a new EVIC message, “Service DEF System Engine Will Not Start – See Dealer” (see 

Stage 3, Figure 12). Staff drove for one additional mile passed the countdown 

expiration and executed a key-off/restart event; the vehicle did not start (trip odometer = 

3,123 miles). The vehicle inducements were consistent with the February 2009 U.S. 

EPA Guidance and the vehicle owner’s manual. 

Using an inexpensive generic OBD II scan tool, ARB staff was able to clear the stored 

DTCs. The following is a list of the stored DTCs: P205B-Reductant Tank Temp Circuit; 

P20E8-Reductant Injector Circuit Low (Bank 1 Unit 1) and P2048-Reductant Injector 

Valve Circuit Low. Leaving the DEF doser injector disconnected, ARB staff cleared the 

DTCs with the scan tool, which extinguished all visual and audible messages/alerts, and 

removed the no-start condition. 

The ability to reset the no-start condition and clear DTCs with a generic OBD scan tool 

warranted further investigation. With the doser disconnected, staff drove the vehicle 

and just as before, the EMD MIL immediately illuminated. The vehicle was driven over 

the designated route to determine whether the SCR system inducements could be reset 

at any time. After approximately 200 miles of driving, the vehicle was refueled and the 
36

generic scan tool was used to reset the EMD MIL once again. The vehicle was 

operated for an additional 250 miles before entering the 500 mile no-start countdown. 

After reaching zero miles on the countdown, staff executed a key-off/restart event and 

the vehicle did not start. The DTCs were again cleared with the generic scan tool and 

the vehicle started without incident. This confirmed that a generic scan tool could be 

used to reset the warning system, thus allowing at least another 750 miles of operation 

before a reoccurrence of a no-start condition. Therefore, the warning system seemed to 

be vulnerable to indefinite resetting of the SCR system allowing indefinite vehicle 

operation. ARB has discussed the scan tool issue with all manufacturers, pointing out 

that this capability is not acceptable and has indicated to manufacturers that it must be 

corrected as soon as possible, but in no case later than the 2013 model year. 

d) Vehicle 3’s Inducement Test Summary

The primary inducement for this vehicle was a 500 mile countdown to no-start preceded 

by various warning messages and chimes based on the cycle. With the exception of 

the malfunctioning DEF heater system that caused the DEF system to overheat and 

stop dosing, the DEF Depletion Cycle was consistent with the February 2009 U.S. EPA 

Guidance and the vehicle owner’s manual. Cummins has developed a correction for 

the malfunctioning DEF heater system and has issued Technical Service Bulletin No. 

25-002-10 to remedy the DEF overheating problem. In addition, while this vehicle was 

undergoing the 500 mile countdown event, the DEF level changed from 0% to 1% after 

an overnight park thus eliminating the 500 mile countdown. Although the 500 counter 

was reinitiated 35 miles later, this is a concern that staff will investigate with Cummins. 

For the DEF Contamination and DEF Tampering Cycles, audible chimes, visual 

messages and an illuminated EMD MIL alerted the driver of an existing DEF system 

issue needing the driver’s attention approximately 250 miles after detection of the issue. 

Since no repairs were performed after the first 250 miles for either cycle, the vehicle 

entered a 500 mile countdown to no-restart while alerting the driver with audible and 

visual messages that the engine would not restart when the countdown reached zero. 

In this case, the vehicle performed consistent with the 1,000 mile/20 hour severe 
37

inducement point for DEF Contamination, and the 2,000 mile/40 hour severe

inducement point for DEF Tampering as per the February 2009 U.S. EPA Guidance. 

The scan tool clearing capability is believed to be more widespread than this 

manufacturer and has been discussed with all manufacturers, pointing out that this 

capability is not acceptable and must be corrected as soon as possible, but in no case 

later than the 2013 model year.

Regarding the effectiveness of the inducement strategies, ARB staff reported that visual 

and audible warnings/alerts were effective in drawing the driver’s attention for the need 

of SCR-related service. Although this sequence was different than the other two trucks 

evaluated in this report, the 500 mile countdown to a no-restart condition was an 

effective strategy in motivating the driver to pay attention to SCR required service. 

However, the DEF heater malfunction caused more miles than expected to be 

consumed before final immobilization was encountered during the DEF Depletion event. 

Therefore, while the inducement strategies were consistent with the February 2009 U.S. 

EPA Guidance for the majority of the testing, further evaluation is warranted on this 

vehicle once the DEF heater malfunction is corrected. 

e) Vehicle 3’s Emissions Measurements 

Test Vehicle 3 was outfitted with a PEMS unit which measured NOx emissions 

continuously as the vehicle was operated over the designated route. Emissions were 

measured under the following conditions: with appropriate DEF in the tank, with the 

DEF tank empty, with it filled with water, and while the DEF/SCR system was tampered. 

Figure 13 (see below) is a summary of the NOx emissions measured for each of these 

test cycles. When operating in normal DEF conditions and throughout the entire DEF 

Depletion Cycle, NOx was within control limits. This was attainable because the design 

of the SCR system allowed the vehicle to go into the no-start condition with a nominal 

amount of DEF remaining in the tank (i.e., with NOx measuring within control limits it 
38

was assumed a portion of DEF remained in the tank). However, when the vehicle was 

operated in the DEF Contamination Cycle and DEF System Tampering Cycle, the NOx 

emissions increased and were about four times higher as compared to normal operation 

with DEF (i.e., as the vehicle normally operates with a supply of DEF).

Figure 13 – NOx Emissions Cummins 6.7L

Note: The PEMS values in Figure 13 were measured values taken during this test program while the 

vehicle was operated under on-road conditions (Note: One Trip = Emissions test run from El Monte, CA to 

Baker, CA only). The Family Emission Limit (FEL) 0.5 g/bhp-hr NOx standard requires emission 

measurement under laboratory conditions and the Not to Exceed (NTE) 0.75 g/bhp-hr standard requires 

specific on-road operation for attaining emission measurements. These standards were only provided for 

general reference only. The PEMS unit used for this operation meets the U.S. EPA requirements as per 

40 CFR 1065.

Emissions 

Averaged 

Over 3 

Trips

Emissions 

Averaged 

Over 1 

Trip

Emissions 

Averaged 

Over 2 

Trips

Emissions 

Averaged 

Over 2 

Trips
39

III. Overall Conclusions

The widespread availability of DEF was uncertain prior to the first year of sale in the 

U.S. of SCR-equipped engines (2010). The U.S. EPA guidance accommodated this 

uncertainty by allowing the engine to be designed to allow for some operation of the 

truck after the warning system indicated DEF was soon to be depleted. The purpose of 

this provision was to allow the truck operator several opportunities to procure DEF 

before the more disabling inducements were initiated. As the ARB survey showed, a 

small percentage of operators found DEF unavailable during 2010. The survey also 

showed, however, that DEF was widely available, and only 1 of 69 truck operators 

operated their truck without DEF because of DEF unavailability. 

For the three vehicles evaluated in this study, ARB staff found that the warnings and 

inducement strategies incorporated by the engine manufacturers were consistent with 

the February 2009 U.S. EPA Guidance (see Figure 14). However, the large Cummins 

engine had a programming error that caused the intended severe inducement (5 mph 

maximum operating speed) to not occur. Cummins has recalled the affected engines 

and has also made the change in production. The test vehicle also had a defective 

throttle position sensor which made assessing the effectiveness of the power de-rate 

strategy difficult to assess. The smaller Cummins engine had a defective DEF heater 

which caused the truck to operate longer than anticipated before DEF depletion was 

detected. This has been addressed by Cummins through Chrysler with a service 

campaign. 
40

Figure 14 – Test Vehicles Results per the February 2009 U.S. EPA Guidance

TEST CYCLE

TEST VEHICLE

DEF 

Depletion 

Cycle

DEF 

Contamination 

Cycle

DEF System 

Tampering 

Cycle

Comments

#1 

(DDC 12.8L) YES YES INCOMPLETE

#2 

(CUMMINS 14.9L) NO* NO* NO*

* Vehicle did not enter 5 mph 

severe speed limited inducement 

for any of the test cycles. 

Corrective action: Cummins 

voluntary recall campaign 

(C1036).

#3 

(CUMMINS 6.7L) YES** YES YES

** DEF heater circuit problem 

allowed additional miles before 

triggering no-start inducement 

countdown. 

Corrective action: Chrysler 

Technical Service Bulletin

(No. 25-002-10).

Changes for 2011 Models

With DEF widely available in California, ARB has worked with the U.S. EPA and engine 

manufacturers to improve the effectiveness of the SCR monitoring system of 2011 

models. In July 2010, ARB held a joint public workshop with the U.S. EPA discussing 

the changes to the SCR inducement strategies we expected for the 2011 and future 

MYs, as outlined below: 

a. When a low level of DEF remains, for example, sufficient to drive about 100 

miles under typical driving conditions, warning signals begin and become 

increasingly urgent thereafter.

b. After the DEF tank level triggered in paragraph (a) and before an empty DEF 

tank, a noticeable de-rate begins and is sustained until paragraph (c).

c. When the DEF tank is empty, a more significant de-rate occurs. Operation at 

this second de-rate occurs no longer than necessary to safely reach a 

location where the engine can be safely shut down, for example, no more 
41

than one hour. At the end of this period, the vehicle speed is limited to 5 mph 

maximum.

d. Upon a disconnected SCR monitor, sensor, or component, warning signals 

begin and become increasingly urgent thereafter and the engine power will be 

noticeably de-rated.

e. After an hour of operation pursuant to paragraph d., a second significant derate will occur. The engine will operate at this de-rated level for no longer 

than necessary to confirm disconnection, for example, no more than four 

hours. At the end of this period the vehicle speed is limited to 5 mph 

maximum. Normal operation cannot be resumed until the disconnection is 

cleared.

f. If repeated disconnects and reattachments of a SCR monitor, sensor, or 

component are detected, the attributes in paragraph c. apply. Normal 

operation cannot be resumed until the disconnections are cleared.

g. Proper DEF dosing should occur within 40 minutes of a freezing event.

In addition to the above, ARB is also expecting improvements in DEF contamination 

detection. ARB staff is also working with the manufacturers to use only proprietary scan 

tools to reset the system for 2011 and future engines and produce more robust repeat 

tampering detection inducements. In addition, as glitches and/or programming errors 

surface, ARB staff is working with the manufacturers on service campaigns/recalls to fix 

such problems. 
42

IV. Appendix A – Field Survey Forms
43

DEF Availability Survey
44

Diesel Exhaust Fluid Survey

Diesel Exhaust Fluid Survey

Date: ____________ Time: ____________ Location: _________________________

ARB Representative(s): _______________________, ________________________

Truck Make: _____________________ VIN: ________________________________

Odometer: _____________________ DEF Tank Size: Gallon _________

Engine Make: ___________________ Engine Family: ________________________

Engine Serial No.: _______________________________ Engine HP: ____________ 

Diagnostic Trouble Codes: ___________, ___________, ___________, ___________

DEF Quality Check: Take one drop of DEF from truck DEF tank and place on 

refractometer and record results in % of scale from Ethylene Glycol _____________ 

An example of a refractometer view through the viewer is in the image 1 below.

Refractometer lenses should be covered as indicated in image 2 below.

 Image 1 Image 2

 

Check for engine diagnostic lamps that are illuminated on drivers display and record.

Lamps illuminated: ____________________________________________________
45

DRIVERS QUESTIONAIRE:

1. Have you operated your truck without DEF? Yes: ____ No: ____

If yes, how many miles? ___________________

Reason: ________________________________________________________

2. Have you operated your truck on fluids other than DEF in the DEF tank? 

Yes: ____ No: ____

If yes, what fluid did you operate the truck with: ____________

How many miles? ____________

Reason: _________________________________________________________

3. Have you had any problems with your trucks emissions control system?

Yes: ____ No: ____

If yes, what problems have you experienced? ____________________________

________________________________________________________________

4. Have you had any problems locating DEF? Yes: ____ No: ____

If yes, what problems? ______________________________________________

_____________________________________________________________________ 

Comments: ____________________________________________________________

______________________________________________________________________ 

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________
46

V. Appendix B – SCR Test Plan (2R1004)
47

Test Plan

Investigation of Selective Catalysis Reduction NOx Strategy

Project Number: 2R1004

Investigation of SCR Operation

2010 Heavy Duty Diesel

Engine Family ACEXH0912XAP

Engine Family ACEXH0408BAL

Engine Family ADDXH12.8FED

July 29, 2010

Project Engineer:

John O’Cain

Test Engineer:

In-Use Compliance Section

In-Use Vehicle Programs Branch

Mobile Source Operations Division

Air Resources Board

Haagen-Smit Laboratory

9528 Telstar Avenue

El Monte, CA 9l73l
48

TEST PLAN

Selective Catalyst Reduction NOx Strategy Test Program

I. SCOPE

The primary objective of this program is to investigate the effectiveness of driver 

inducements used by Selective Reduction Catalysts (SCR) oxide of nitrogen (NOx) 

controlled engines in actual field operations. For the SCR systems to function properly, 

the drivers are required to periodically fill their vehicle with Diesel Exhaust Fluid (DEF). 

Since DEF must be purchased, drivers might be motivated to operate without DEF 

and/or tamper with the SCR systems so they could reduce their operating costs. This is 

in contrast to ARB’s certification procedures that require that vehicles be equipped with 

sophisticated systems to induce driver responses when drivers fail to add DEF and/or 

tamper with the systems through substituting water or disconnecting hardware. 

The goals of this investigation are to determine; 1) if engine manufacturers are 

producing engines as certified and 2) the effectiveness of driver inducements for driver 

actions or inactions relating to the use of DEF. The project will determine how long a 

vehicle will operate once the DEF supply is depleted and evaluate the vehicles’ engine 

operation and operator alert systems as the DEF is being depleted. Staff will determine 

if the vehicle can be normally operated with water as a substitute for DEF. Additionally, 

staff will evaluate the case of a hardware tamper by disconnecting the DEF injector. For 

baseline operation (normal DEF dosing) and all specified routes (no DEF, water as a 

substitute for DEF, and hardware tampering--see Flowcharts), staff will measure NOx 

emissions utilizing a Portable Emissions Measurement System (PEMS). 

To investigate the implementation of driver inducements, the IUCS staff will procure 

three HDD vehicles equipped with 2010 diesel engines using SCR technology. 
49

The three test vehicles to be procured for this program will consist of one vehicle 

equipped with a 14.9L Cummins engine, one with a 6.7L Cummins engine and one with 

a 12.8L Detroit Diesel engine. 

II. PROGRAM MANAGEMENT

The In-Use Compliance Section (IUCS) is charged with administering this test program. 

The project engineer will be the contact person for all issues relating to the completion 

of this program.

III. VEHICLE PROCUREMENT

The ARB Procurement Contractor, California Environmental Engineering (CEE), will 

provide three test vehicles for this program. These vehicles will be from Cummins 

engine families ACEXH0912XAP and ACEXH0408BAL, and Detroit Diesel engine 

family ADDXH12.8FED. The vehicle locations will be provided to the ARB Stockton 

laboratory on or about August 3, 2010.

IV. VEHICLE DELIVERY AND CHECK-IN

Two vehicles will be delivered to the Heavy-Duty Diesel I/M Development Section 

(HDDV I/M DS) at ARB’s Stockton laboratory. The Southern California vehicle will be 

delivered to the Mobile Source Control Division’s In-Use Retrofit Section in El Monte. 

Vehicles will be checked-in and all pre-existing damage will be documented and 

photographed upon check-in. PEMS units will be installed on each vehicles, checked 

for proper operation and calibrated after check-in is completed.

V. TEST FUEL REQUIREMENTS

Testing for this program will be performed on commercial diesel fuel. Diesel fuel and 

DEF will be purchased through a local supplier using a California Voyager Card. All 

California Voyager Card purchases must have a receipt and all receipts must 

accompany the California Voyager Card when returned to the Vehicle Diagnostic and 
50

Repair Section when testing is complete and the vehicles are returned to the rental 

agencies. Please make every effort to keep all receipts.

VI. VEHICLE MAINTENANCE

Any necessary vehicle maintenance will be performed by the HDDV I/M DS staff. 

Maintenance that cannot be performed by staff will be performed by a local 

maintenance vendor. The project engineer will be notified of any maintenance prior to 

maintenance being performed. 

VII. TESTING

Testing of the vehicles will be performed on California highways using a PEMS system 

to collect NOx emission samples while testing. A Pre Drive Inspection Form is enclosed 

and must be completed prior to each drive. Charts A shows the basic flow for this 

program and Charts 1-9 identify the actual test cycle sequence to be performed on each 

vehicle for the given test cycle condition. NOx emissions levels will be monitored and 

recorded during all driving sequences (the baseline condition is defined as when normal 

DEF dosing is occurring under various driving conditions). All test sequence conditions 

will be documented in the Vehicle Test Cycle Operation Form (enclosed). The HDDV 

I/M DS staff will install the PEMS units on the Northern California vehicles and the v InUse Retrofit Section will install the PEMS system on the Southern California vehicles. 

All PEMS will be calibrated as necessary. Each vehicle will have two staff on-board 

during all phases of testing. One will operate the vehicle and the second will document 

the operation of the vehicles. Vehicles will be operated for as many miles as possible 

during a normal shift. Vehicles will be ballasted with weight to near full load capacity; 

therefore all safety precautions must be taken to safely operate these vehicles. All 

State and federal traffic laws will be adhered to. In the case of an accident, the 

California Highway Patrol or local police authority and the project managers must be 

notified immediately.

Vehicle testing will be as follows (NOx emissions monitored and recorded for all below):
51

• One testing sequence with DEF in the tank, normal dosing conditions 

• One testing sequence with no DEF in the tank; all the way to trigger engine 

immobilization

• One testing sequence with water replacing DEF; all the way to trigger engine 

immobilization

• One testing sequence with the DEF injector disconnected; all the way to trigger 

engine immobilization

Photographs will be taken whenever an event occurs on the DEF drivers’ information 

display. These photographs will become part of the final data and forwarded to the 

project engineer.

Two on-road test routes, one route beginning at the Stockton Laboratory and one route 

starting at the HSL will be utilized. The northern California route will start at the 

Stockton laboratory and proceed to Truckee. At Truckee the driver will allow the truck 

to idle for five minutes prior to the return drive to Stockton. NOx will be recorded 

throughout the entire drive cycle. See enclosed maps for driving route (Map 1 and Map 

2). The In-Use Retrofit Section will use an alternate route in Southern California. This 

route will start in El Monte and proceed to Baker. At Baker the truck will idle for five 

minutes prior to the return drive to El Monte. NOx emissions will be recorded 

throughout the entire drive cycle. See enclosed maps for driving route (Map 3 and Map 

4). These routes are expected to operate the engine under various power 

requirements. During the engine torque de-rate periods, the vehicle driver feels it is 

unsafe to operate the vehicles over the driving routes described in this test plan, the 

driver may choose a route where the vehicle can be safely operated.

Each vehicle must have an experimental permit in the vehicle while operated on 

highways.
52

VIII. DATA HANDLING AND PROCESSING

All raw data (notes, pictures, PEMS data printouts, etc.) will be provided to the project 

engineer who, together with the test engineer, will review all test data for completeness 

and accuracy.

IX. DOCUMENTATION 

It is of the utmost importance that all forms, documents, test data sheets, etc., are 

accurate and complete and submitted to the project engineer. State digital cameras 

serial numbers 20018325 and 20050849 will be supplied to the HDDV I/M DS staff for 

photographs. Camera batteries should be checked for charge level and recharged as 

necessary. Cameras and photographs’ must be returned to the project engineer up 

completion of testing. 

X. LABORATORY VISITORS

The project engineer must be advised of any non-ARB employees that are involved with 

the project. No persons other that ARB employees may occupy the vehicles while they 

are operated on the highway without the approval of the project engineer.

XI. VEHICLE RELEASE

When a vehicle is released from the program, the project engineer will:

• Notify the procurement contract contact person (Bob Torres) of the vehicle’s 

release.

• The HDDV I/M DS staff will de-prep and return the vehicle to the supplier 

where the vehicle was received.

XII. TEST REPORT

A final project report will be submitted to management for review/approval as soon as 

possible after the completion of the field portion of the project.

Enclosures
53

Pre Drive Inspection Form

Project Number: ________________ Date: ______________

Vehicle License Number: ______________ Vehicle Number: __________

Driver: ____________________ Observer: ____________________ 

Items Checked Ok Comments 

PEMS calibration

Fuel Level

DMV pre drive inspection

Oil level

DEF level and condition

Brakes

Tires 

Fuel Refilled (gallons)

DEF Refill (gallons/quarts)

Fluids:

Other:
54

Chart A

SCR Test Flowchart

Select test 

vehicles

Deliver test vehicles to Stockton 

emissions lab

Equip test vehicles with PEMS units and 

calibrate

END

Test data good

Review test data

Yes

Notify Bob Torres of 

completed project and 

return vehicle to supplier

Conduct Test Cycles as Prescribed in 

Charts 1-9

Disconnect PEMS units and re-set 

vehicles back to an as-received 

condition

Determine if further 

testing can be done to 

correct data.

Can more testing 

be performed?

No

Yes

No
55

CHART 1

DDC 12.8L DEF TEST PROGRAM OPERATION

(Low DEF Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 75 %

DEF Tank Fill: 20% Capacity

DRIVE:

Drive the truck per the test plan 

route to deplete DEF. Objective is 

to deplete DEF to empty (this may 

take several hundred miles).

DOCUMENT:

As DEF depletes, certain amber 

warning lamp (AWL) events will 

occur when DEF drops below 

10%. Note mileage, AWL status, 

engine de-rate status. When DEF 

drops below 5%, 25% engine derate should occur. On an 

approximant level portion of road 

and on a grade, Momentarily 

apply full throttle to determine if 

truck will exceed 55 mph. 

Document vehicle response. 

FUEL TANK FILL:

When DEF drops to 0%, stop 

truck (key off) and fill with a 

minimum of 30% fuel tank 

capacity. 

DRIVE:

Start truck and continue to drive 

vehicle. 

Did truck de-rate to 5 

mph within 1 hr of restart?

DRIVE/DOCUMENT:

Document conditions of truck after 

1 hr and drive truck for 600 miles 

since last key start. 

FUEL TANK FILL:

Fill fuel tank with a minimum of 

30% fuel tank capacity. 

DRIVE:

Start truck and continue to drive 

vehicle. 

Did truck de-rate to 5 

mph within 1 hr?

NO

DOCUMENT:

Document vehicle drivability and 

any de-rate inducements that may 

have occurred within the hour.

NO

YES

END

DOCUMENT:

Note conditions when 

vehicle de-rated to 5 

mph. 

YES

END

DOCUMENT:

Note conditions when 

vehicle de-rated to 5 

mph. 
56

CHART 2

DDC 12.8L DEF TEST PROGRAM OPERATION

(DEF Dilution Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 75 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with Water to 

20% Capacity (DO NOT ADD 

DEF)

DRIVE:

Start vehicle and time how long it 

takes for AWL to illuminate. Drive 

the truck per the test plan route to 

deplete DEF tank. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

Did truck de-rate to 5 

mph within 1 hr?

DRIVE/DOCUMENT:

Document conditions after 1 hr, 

and drive truck for 600 miles since 

last key start. 

FUEL TANK FILL:

Fill fuel tank with a minimum of 

30% fuel tank capacity. 

DRIVE:

Start truck and time how long it 

takes for truck to de-rate to 5 

mph. 

Did truck de-rate to 5 

mph within 1 hr?

END

NO

DOCUMENT:

Document vehicle drivability and 

any de-rate inducements that may 

have occurred over the last hour.

NO

YES

YES

END

DRIVE:

Continue to drive vehicle for 600 

miles.

DOCUMENT:

 Continue to monitor and 

document AWLs, audible noise 

signals, and de-rate issues as 

DEF tank depletes. 

FUEL TANK FILL:

Stop truck (key off) and fill with a 

minimum of 30% fuel tank 

capacity. 

DRIVE:

Start truck and time how long it 

takes for truck to de-rate to 5 

mph. 

DOCUMENT:

Note time and 

mileage when vehicle 

de-rated to 5 mph. 

DOCUMENT:

Note time and 

mileage when vehicle 

de-rated to 5 mph. 
57

CHART 3

DDC 12.8L DEF TEST PROGRAM OPERATION

(DEF Tamper Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL/MAINTENANCE:

FUEL Tank: Fill 75 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with to 100% 

capacity with DEF

Maintenance: Disconnect DEF 

dousing valve

DRIVE:

Start vehicle and time how long it 

takes for AWL to illuminate. Drive 

the truck per the test plan route. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

Did truck de-rate to 5 

mph within 1 hour of restart?

NO

DOCUMENT:

Document vehicle drivability and 

any de-rate inducements that may 

have occurred over the last hour.

YES

DRIVE:

Continue to drive vehicle for 1600 

miles.

DOCUMENT:

 Continue to monitor and 

document AWLs, audible noise 

signals, and de-rate issues. 

FUEL TANK FILL:

After 1600 miles are accumulated, 

stop truck (key off) and fill with a 

minimum of 30% fuel tank 

capacity. 

DRIVE:

Start truck and time how long it 

takes for truck to de-rate to 5 

mph. 

DOCUMENT:

Note time and 

mileage when vehicle 

de-rated to 5 mph. 

END

RESET VEHICLE:

Maintenance: 

Reconnect DEF 

Dousing Valve

DRIVE:

Drive vehicle to ensure truck is 

operating within acceptable 

conditions (i.e., no AWLs, and 

acceptable drivability).
58

CHART 4

CUMMINS 14.9L DEF TEST PROGRAM OPERATION

(Low DEF Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 75 %

DEF Tank Fill: 20% Capacity

DRIVE:

Drive the truck per the test plan 

route to deplete DEF. Objective is 

to deplete DEF to empty (this may 

take several hundred miles). 

DOCUMENT:

As DEF depletes, certain amber 

warning lamps (AWL) and audible 

signals will occur when DEF drops 

below 10%. Note mileage, AWL 

status, audible alerts, engine derate status.

KEY OFF:

When DEF drops to 0%, stop 

truck (key off). 

DRIVE:

Start truck and time how long it 

takes for truck to de-rate to 5 

mph. 

Did truck de-rate to 5 

mph within 1 hr of restart?

DOCUMENT:

Document vehicle drivability and 

any de-rate inducements that may 

have occurred over the last hour.

NO

END

DOCUMENT:

Note time and 

mileage when vehicle 

de-rated to 5 mph. 

Yes
59

CHART 5

CUMMINS 14.9L DEF TEST PROGRAM OPERATION

(DEF Dilution Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 100 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with Water to 

100% Capacity (DO NOT ADD 

DEF)

DRIVE:

Start vehicle and drive the truck 

per the test plan route to deplete 

DEF tank. Time how long it takes 

vehicle to illuminate AWLs. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

Did the red lamp 

indicator and AWLs 

illuminate solid?

DRIVE/DOCUMENT:

Document all de-rate 

occurrences. Drive vehicle to a 

Cummins authorized repair 

facility. Turn off truck at the repair 

facility during their business 

hours. Turn off truck and then restart. 

Did the truck re-start?

END

DOCUMENT:

Document vehicle 

drivability and any derate inducements that 

may have occurred.

END

DRIVE:

Continue to drive vehicle for 600 

miles since beginning this cycle. 

DOCUMENT:

 Continue to monitor and 

document AWLs, audible noise 

signals, and de-rate issues as 

DEF tank depletes. 

KEY OFF EVENT:

Stop truck after accumulating 600 

miles. 

DRIVE:

Re-start truck and drive 600 more 

miles. The red DEF warning lamp 

and AWLs should illuminate solid 

during this drive cycle.

DRIVE/DOCUMENT:

Ensure truck returns 

back to normal 

operation. Document 

status. 

DOCUMENT:

Note conditions of 

the vehicles and any 

inducements that 

may have occurred. 

MAINTENANCE:

Have repair facility re-set DEF 

warning light system. Operator 

may want to try empting the DEF 

tank and refill with 100% DEF to 

restart system. 

NO

YES

YES

NO
60

CHART 6

CUMMINS 14.9L DEF TEST PROGRAM OPERATION

(DEF Tamper Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL/MAINTENANCE:

FUEL Tank: Fill 100 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with to 100% 

capacity with DEF

Maintenance: Disconnect DEF 

dousing valve

DRIVE:

Start vehicle and drive the truck 

per the test plan route. Time how 

long it takes vehicle to illuminate 

AWLs. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

Did truck de-rate to 5 

mph within 1 hour of restart?

NO

DOCUMENT:

Document vehicle drivability and 

any de-rate inducements that may 

have occurred within the last hour.

YES

DRIVE:

Continue to drive vehicle for 600 

miles.

DOCUMENT:

 Continue to monitor and 

document AWLs, audible noise 

signals, and de-rate issues. 

KEY OFF-ON/DRIVE:

Shut down truck and re-start. 

Obtain time and mileage for truck 

to de-rate to 5mph.

DOCUMENT:

Note time and 

mileage when vehicle 

de-rated to 5 mph. 

END

RESET VEHICLE:

Maintenance: 

Reconnect DEF 

Dousing Valve

DRIVE/DOCUMENTATION:

Drive vehicle to ensure truck is 

operating within acceptable 

conditions (i.e., no AWLs, and 

acceptable drivability). Note time 

and mileage to get back to normal 

vehicle operation.

KEY OFF:

Stop truck (key off). 

KEY ON/DRIVE:

Start truck and drive vehicle for 

1600 miles.
61

CHART 7

CUMMINS 6.7L DEF TEST PROGRAM OPERATION

(Low DEF Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 100 %

DEF Tank Fill: 20% Capacity

DRIVE:

Drive the truck per the test plan 

route to deplete DEF. Objective is 

to deplete DEF to empty (this may 

take several hundred miles). 

DOCUMENT:

As DEF depletes, certain amber 

warning lamps (AWL) and audible 

signals will occur when DEF drops 

below 10%. Note mileage, AWL 

status, audible alerts, engine derate status.

Did the truck re-start?

DRIVE/DOCUMENT:

Document time and mileage of restart. 

Yes

END

DOCUMENT:

Note time and 

mileage of this 

operation. 

No

MESSAGE/DOCUMENT:

When message appears vehicle 

won’t start at next key start, note 

time and mileage. At this point 

return to the El Monte lab.

KEY OFF/KEY ON:

When MESSAGE appears, stop 

truck (Key Off). Re-start vehicle 

(Key On).
62

MESSAGE/DOCUMENT:

When message appears stating 

that vehicle won’t start on next 

key start, note time and mileage. 

At this point return to the El Monte 

lab.

CHART 8

CUMMINS 6.7L DEF TEST PROGRAM OPERATION

(DEF Dilution Test Cycle)

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL:

FUEL Tank: Fill 100 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with Water to 

100% Capacity (DO NOT ADD 

DEF)

DRIVE:

Start vehicle and drive the truck 

per the test plan route. Time how 

long it takes vehicle to illuminate 

AWLs. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

KEY OFF/KEY ON:

When MESSAGE appears, stop 

truck (Key Off). Re-start vehicle 

(Key On).

Did the truck re-start?

DRIVE:

Document time and mileage of 

attempted re-start. 

END

DOCUMENT:

Note time and 

mileage of this 

operation. 

Yes

No
63

CHART 9

CUMMINS 6.7L DEF TEST PROGRAM OPERATION

(DEF Tamper Test Cycle)

MESSAGE/DOCUMENT:

When message appears stating 

that vehicle won’t start on next 

key start, note time and mileage. 

At this point return to the El Monte 

lab

DETERMINE:

FUEL Tank Size: Document

DEF Tank Size: Document

START

TANK FILL/MAINTENANCE:

FUEL Tank: Fill 75 %

DEF Tank Fill: Verify DEF is at 

0% fill; Fill DEF tank with to 100% 

capacity with DEF

Maintenance: Disconnect DEF 

dousing valve

DRIVE:

Start vehicle and drive the truck 

per the test plan route. Time how 

long it takes vehicle to illuminate 

AWLs. 

DOCUMENT:

Note when AWL illuminated (time 

and mileage). 

KEY OFF/KEY ON:

When MESSAGE appears, stop 

truck (Key Off). Re-start vehicle 

(Key On).

Did the truck re-start?

DOCUMENT:

Document time and mileage of restart. 

DOCUMENT:

Note time and 

mileage of this 

operation. 

Yes

No

END

RESET VEHICLE:

Maintenance: 

Reconnect DEF 

Dousing Valve

DRIVE:

Drive vehicle to ensure truck is 

operating within acceptable 

conditions (i.e., no AWLs, and 

acceptable drivability).
64

Map 1 - Stockton to Truckee Route

• Summary: 155.3 miles (2 hours, 39 minutes)

Time Mile Instruction For Toward

9:00 AM 0.0 Depart 2769 Teepee Dr, Stockton, CA 

95205 on Teepee Dr (West)

0.1 mi

9:00 AM 0.1 Turn RIGHT (North-East) onto Cherokee Rd 0.2 mi

9:01 AM 0.3 Take Ramp (RIGHT) onto SR-99 1.5 mi CA-99 / Los Angeles

9:03 AM 1.9 Road name changes to SR-26 [SR-99] 0.3 mi

9:03 AM 2.2 At exit 254A, take Ramp (RIGHT) onto SR-4 

[Ort Lofthus Fwy]

3.0 mi CA-4 / I-5 / Downtown Stockton / 

San Francisco

9:06 AM 5.2 Turn RIGHT onto Ramp 0.3 mi I-5 / CA-4 / San Francisco / Los 

Angeles / Sacramento

9:07 AM 5.5 Take Ramp (LEFT) onto I-5 0.8 mi I-5 / Sacramento

9:08 AM 6.3 At exit 473, turn RIGHT onto Ramp 0.3 mi Pershing Avenue

9:08 AM 6.5 Road name changes to N Pershing Ave 142 yds

9:08 AM 6.6 Turn LEFT (West) onto W Flora St, then 

immediately turn LEFT (South) onto N 

Pershing Ave

0.2 mi

9:10 AM 6.9 Turn RIGHT (West) onto W Fremont St 0.1 mi

9:11 AM 7.0 At near Stockton, return East on W 

Fremont St

0.1 mi

9:11 AM 7.1 Turn LEFT (North) onto N Pershing Ave 0.1 mi

9:12 AM 7.2 Take Ramp (LEFT) onto I-5 49.2 mi I-5 / Sacramento

10:01 

AM

56.5 At exit 522, turn RIGHT onto Ramp 0.2 mi I-80 / San Francisco / Reno

10:01 

AM

56.7 Take Ramp (RIGHT) onto I-80 98.4 mi I-80 / Reno

Road widening near Roseville (NB) 

(October 10, 2008 - March 24, 2011)

11:39 

AM

155.1 At exit 185, turn RIGHT onto Ramp 0.2 mi CA-89 / Lake Tahoe
65

Map 2 - Return Route

Summary: 155.6 miles (2 hours, 37 minutes)

Time Mile Instruction For Toward

12:00 

PM

0.0 Depart near Gateway on SR-89 (North) 120 

yds

CA-89 / US-80 W / Donner Pass 

Rd / Sacramento

12:00 

PM

0.1 At roundabout, take the SECOND exit onto 

Ramp

0.2 mi I-80 / Sacramento

12:00 

PM

0.3 Merge onto I-80 97.9 mi

Reconstruction near Eder (WB) (March 1, 

2009 - February 29, 2012)

1:37 PM 98.2 Turn RIGHT onto Ramp 0.2 mi CA-99 / I-5 / Los Angeles / Redding

1:37 PM 98.4 Take Ramp (LEFT) onto I-5 [SR-99] 49.7 mi I-5 / CA-99 / Sacramento / Los 

Angeles

2:27 PM 148.1 At exit 473, turn RIGHT onto Ramp 0.2 mi Fremont St / Oak St

2:28 PM 148.3 Turn LEFT (East) onto W Fremont St 87 yds

2:28 PM 148.4 At near Stockton, take Ramp (LEFT) onto I50.4 mi I-5 / Tracy

2:29 PM 148.8 Turn RIGHT onto Ramp 0.3 mi Fresno Avenue / CA-4 E / 

Downtown Stockton

2:29 PM 149.1 Keep LEFT to stay on Ramp 0.7 mi CA-4 / CA-99 / Downtown Stockton

2:30 PM 149.7 Take Ramp (LEFT) onto SR-4 [Ort Lofthus 

Fwy]

2.7 mi

2:32 PM 152.5 Take Ramp (LEFT) onto SR-26 [SR-99] 0.7 mi CA-99 / Sacramento

2:33 PM 153.2 At exit 254B, road name changes to SR-99 1.8 mi

2:35 PM 154.9 At exit 256, turn RIGHT onto Ramp 0.1 mi Cherokee Rd

2:36 PM 155.1 Keep RIGHT to stay on Ramp 87 yds Cherokee Rd West

2:36 PM 155.1 Keep STRAIGHT onto Cherokee Rd 0.4 mi

2:37 PM 155.5 Turn LEFT (East) onto Teepee Dr 0.1 mi

2:37 PM 155.6 Arrive 2769 Teepee Dr, Stockton, CA 95205
66

Map 3 - El Monte to Baker

Summary: 166.9 miles (2 hours, 22 minutes)

Time Mile Instruction For Toward

9:00 AM 0.0 Depart 9528 Telstar Ave, El Monte, CA 

91731 on Telstar Ave (East)

0.4 mi

9:00 AM 0.4 Turn RIGHT (East) onto Flair Dr 0.2 mi

9:01 AM 0.6 Take Ramp (RIGHT) onto I-10 [San 

Bernardino Fwy]

29.8 mi I-10

9:26 AM 30.4 Take Ramp (RIGHT) onto I-15 [Ontario Fwy] 14.1 mi I-15 / Barstow / Las Vegas

9:38 AM 44.5 At exit 123, take Ramp (LEFT) onto I-15 

[Barstow Fwy]

121.2 

mi

I-15 / Barstow

11:20 

AM

165.7 Turn RIGHT onto Ramp 0.2 mi CA-127 / Kelbaker Rd / Death 

Valley

11:21 

AM

166.0 Turn LEFT (North-West) onto SR-127 

[Kelbaker Rd]

0.9 mi

11:22 

AM

166.9 Arrive Baker
67

Map 4 - Baker to El Monte

Summary: 168.3 miles (2 hours, 24 minutes)

Time Mile Instruction For Toward

9:00 AM 0.0 Depart Baker on SR-127 (South) 0.7 mi

9:01 AM 0.7 Take Ramp (RIGHT) onto I-15 120.8 

mi

I-15

10:43 

AM

121.4 Take Ramp (RIGHT) onto I-15 [Ontario Fwy] 14.3 mi I-15 / Los Angeles / San Diego

10:55 

AM

135.8 Take Ramp (RIGHT) onto I-10 [San 

Bernardino Fwy]

31.3 mi I-10 / Los Angeles

11:21 

AM

167.0 At exit 26B, turn RIGHT onto Ramp 0.1 mi CA-19 / Rosemead Blvd

11:21 

AM

167.2 Keep STRAIGHT to stay on Ramp 0.1 mi CA-19 N / Rosemead Blvd / 

Pasadena

11:22 

AM

167.3 Keep LEFT to stay on Ramp 32 yds Rosemead Blvd

11:22 

AM

167.3 Bear LEFT (West) onto Glendon Way 43 yds

11:22 

AM

167.3 Turn LEFT (South) onto SR-19 [Rosemead 

Blvd]

0.5 mi

11:22 

AM

167.8 Turn LEFT (North-East) onto Telstar Ave 0.5 mi

11:24 

AM

168.3 Arrive 9528 Telstar Ave, El Monte, CA 

91731
68 

Vehicle Test Cycle Operation Form

Project #: __________________ Date: ______________ Vehicle #: ________ Chart # ________

Driver: ___________________ Observer: __________________ Vehicle License #: ______________

Fuel Tank Capacity: _______ gal DEF Tank Capacity: ________ gal Test Cycle: _______________

Date Time Odometer

DEF

Tank

Type 

Fluid 

Added

Amt 

Fluid

Added

DEF 

Gauge 

Level

Diesel 

Fuel 

Added

Diesel 

Gauge 

Level

Engine 

Performance. 

Note any 

changes of 

power derate

Engine 

Start

Road 

Grade

%

Vehicle

Speed

How 

Many 

AWLs

Red Light 

Indicator Comments