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ATTACHMENT I 

Proposed 15-Day Modifications to Sections 1968.2, 1971.1, and 1971.5, title 13, 

California Code of Regulations 

Set forth below are proposed modifications to the amendments to California Code of 

Regulations, title 13, sections 1968.2 and 1971.1 and to California Code of Regulations, 

title 13, section 1971.5 that were presented to the Board for adoption on May 28, 2009. 

The original proposed amendments were made available to the public as part of the 

45-Day Notice on April 10, 2009. The original proposed amendments to sections 

1968.2 and 1971.1 are shown in single underline to indicate additions and single 

strikeout to indicate deletions made to the existing text that was adopted for section 

1971.1 in 2005 and was last amended for section 1968.2 in 2006. The regulatory text 

for section 1971.5 that was proposed as part of the 45-Day Notice is indicated in plain 

type. The proposed modifications made available by the “15-day” notice are shown in 

double underline to indicate additions and double strikeout to indicate deletions. 

Various portions of the regulations that are not modified by the staff’s suggested 

modifications are omitted from the text shown and indicated by: 

“ * * * * ” 
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§1968.2. Malfunction and Diagnostic System Requirements -- 2004 and 

Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty 

Vehicles and Engines 

* * * * 

(d) GENERAL REQUIREMENTS. 

* * * * 

(2) MIL and Fault Code Requirements. 

* * * * 

(2.5) Erasing a permanent fault code. The OBD system shall erase a permanent 

fault code under the following conditions:

* * * * 

(2.5.2) If all fault information in the on-board computer other than the permanent 

fault code has been cleared (i.e., through the use of a scan tool or battery 

disconnect) and the OBD II system is not commanding the MIL on: 

* * * * 

(B) Except as provided for in sections (d)(2.5.2)(D) and (E), if the monitor of 

the malfunction that caused the permanent fault code to be stored is not 

subject to the minimum ratio requirements of section (d)(3.2) (e.g., 

gasoline misfire monitor, fuel system monitor, comprehensive component 

circuit continuity monitors), the OBD II system shall erase the permanent 

fault code at the end of a driving cycle if: 

(i) The monitor has run and made one or more determinations during a 

driving cycle that the malfunction of the component or the system is not 

present and has not made any determinations within the same driving 

cycle that the malfunction is present; 

(ii) The monitor has not made any determinations that the malfunction is 

present subsequent to the most recent driving cycle in which the 

criteria of section (d)(2.5.2)(B)(i) are met; and 

(iii) The following criteria are satisfied on any single driving cycle (which 

may be a different driving cycle than that in which the criteria of section 

(d)(2.5.2)(B)(i) are satisfied): 

a. Cumulative time since engine start is greater than or equal to 600 

seconds; 

b. Except as provided in section (d)(2.5.2)(B)(iii)e. below, Ccumulative 

vehicle operation at or above 25 miles per hour occurs for greater 

than or equal to 300 seconds (medium-duty vehicles with diesel 

engines certified on an engine dynamometer may use cumulative 

operation at or above 15% calculated load1150 rpm in lieu of at or 

above 25 miles per hour for purposes of this criteria); and

c. Continuous vehicle operation at idle (i.e., accelerator pedal released 

by driver and either vehicle speed less than or equal to one mile 

per hour or engine speed less than or equal to 200 rpm above 

normal warmed-up idle (as determined in the drive position for 
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vehicles equipped with an automatic transmission)) for greater than 

or equal to 30 seconds; and

d. For 2013 and subsequent model year engines, Tthe monitor has not 

made any determination that the malfunction is present.

e. For 2004 through 2012 model year medium-duty vehicles with diesel 

engines certified on an engine dynamometer, manufacturers may 

use diesel engine operation at or above 15 percent calculated load 

in lieu of 1150 rpm for the criterion in section (d)(2.5.2)(B)(iii)b. 

above.

(iv) Monitors required to use “similar conditions” as defined in section (c) 

to store and erase pending and confirmed fault codes may not require 

that the similar conditions be met prior to erasure of the permanent 

fault code. 

* * * * 

(4) In-Use Monitor Performance Ratio Definition. 

* * * * 

(4.3) Denominator Specifications 

* * * * 

(4.3.2) Specifications for incrementing: 

* * * * 

(B) The denominator for each monitor shall be incremented within ten 

seconds if and only if the following criteria are satisfied on a single driving 

cycle: 

(i) Cumulative time since engine start is greater than or equal to 600 

seconds while at an elevation of less than 8,000 feet above sea level 

and at an ambient temperature of greater than or equal to 20 degrees 

Fahrenheit; 

(ii) Except as provided in section (d)(4.3.2)(B)(iv) below, Ccumulative 

vehicle operation at or above 25 miles per hour occurs for greater than 

or equal to 300 seconds while at an elevation of less than 8,000 feet 

above sea level and at an ambient temperature of greater than or 

equal to 20 degrees Fahrenheit (medium-duty vehicles with diesel 

engines certified on an engine dynamometer may use cumulative 

operation at or above 15% calculated load1150 rpm in lieu of at or 

above 25 miles per hour for purposes of this criteria); 

(iii) Continuous vehicle operation at idle (i.e., accelerator pedal released 

by driver and either vehicle speed less than or equal to one mile per 

hour or engine speed less than or equal to 200 rpm above normal 

warmed-up idle (as determined in the drive position for vehicles 

equipped with an automatic transmission)) for greater than or equal to 

30 seconds while at an elevation of less than 8,000 feet above sea 

level and at an ambient temperature of greater than or equal to 20 

degrees Fahrenheit;.
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(iv) For 2004 through 2012 model year medium-duty vehicles with diesel 

engines certified on an engine dynamometer, manufacturers may use 

diesel engine operation at or above 15 percent calculated load in lieu 

of 1150 rpm for the criterion in section (d)(4.3.2)(B)(ii) above. 

* * * * 

(F) In addition to the requirements of section (d)(4.3.2)(B) above, the 

denominator(s) for the following monitors of output components (except 

those operated only at engine start-up and subject to the requirements of 

the previous section (d)(4.3.2)(E)) shall be incremented if and only if the 

component is commanded to function (e.g., commanded “on”, “open”, 

“closed”, “locked”, etc.) on two or more occasions for greater than two 

seconds during the driving cycle or for a cumulative time greater than or 

equal to ten seconds, whichever occurs first: 

(i) Air conditioning system (section (e)(12)) 

(ii) Variable valve timing and/or control system (sections (e)(13) and 

(f)(13)) 

(iii) “Other emission control or source device” (sections (e)(16) and (f)(16)) 

(iv) Comprehensive component output component (sections (e)(15) and 

(f)(15)) (e.g., turbocharger waste-gates, variable length manifold 

runners, torque converter clutch lock-up solenoids, etc.) 

(G) For the following monitors, the denominator(s) shall be incremented by 

one if and only if, in addition to meeting during a driving cycle in which the 

following two criteria are met: (1) the requirements of section (d)(4.3.2)(B) 

have been met on at least one driving cycle since the denominator was 

last incremented, and (2) at least the number of cumulative miles of 

vehicle operation since the denominator was last incremented is greater 

than or equal to 500 cumulative miles of vehicle operation have been 

experienced since the last time the denominator was incremented: 

(i) Diesel NMHC converting catalyst (section (f)(1.2.2)) 

(ii) Diesel NMHC converting catalyst other aftertreatment assistance 

functions (sections (f)(1.2.3)(B) and (f)(1.2.3)(D)) 

(iii) Diesel PM filter (sections (f)(9.2.1), (f)(9.2.4), and (f)(9.2.5)) 

* * * * 

(I) For 2013 and subsequent model year vehicles, Iin addition to the 

requirements of section (d)(4.3.2)(B) above, the denominator(s) for the 

following monitors shall be incremented if and only if a regeneration event 

is commanded for a time greater than or equal to ten seconds:

(i) Diesel NMHC converting catalyst other aftertreatment assistance 

functions (sections (f)(1.2.3)(A) and (f)(1.2.3)(C))

(ii) PM filter incomplete regeneration (section (f)(9.2.3))

(iii) PM filter active/intrusive injection (section (f)(9.2.6))

* * * * 

(f) MONITORING REQUIREMENTS FOR DIESEL/COMPRESSION-IGNITION 
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ENGINES. 

(1) NON-METHANE HYDROCARBON (NMHC) CONVERTING CATALYST 

MONITORING 

* * * * 

[Note: No 15-day changes are proposed for the following sections (f)(1.2.2) and 

(f)(1.2.3) however the regulatory text was included since it is referenced in the changes 

proposed above for sections (d)(4.3.2)(G) and (d)(4.3.2)(I).] 

* * * * 

(1.2) Malfunction Criteria: 

* * * * 

(1.2.2) Conversion Efficiency: 

(A) The OBD II system shall detect an NMHC catalyst malfunction when the 

catalyst conversion capability decreases to the point that NMHC

emissions exceed: 

(i) For passenger cars, light-duty trucks, and MDPVs certified to a chassis 

dynamometer tailpipe emission standard: 

a. 5.0 times the applicable FTP NMHC standards for 2004 through 

2009 model year vehicles; 

b. 3.0 times the applicable FTP NMHC standards for 2010 through 

2012 model year vehicles; and 

c. 1.75 times the applicable FTP NMHC standards for 2013 and 

subsequent model year vehicles. 

(ii) For medium-duty vehicles (including MDPVs) certified to an engine 

dynamometer tailpipe emission standard: 

a. 2.5 times the applicable NMHC standards for 2007 through 2012 

model year vehicles; and 

b. 2.0 times the applicable NMHC standards or the applicable NOx 

standard by more than 0.2 g/bhp-hr (e.g., cause emissions to 

exceed 0.4 g/bhp-hr if the emission standard is 0.2 g/bhp-hr) for 

2013 and subsequent model year vehicles. 

(B) Except as provided below in section (f)(1.2.2)(C), if no failure or 

deterioration of the catalyst NMHC conversion capability could result in 

NMHC or NOx emissions exceeding the applicable malfunction criteria of 

section (f)(1.2.2)(A), the OBD II system shall detect a malfunction when 

the catalyst has no detectable amount of NMHC or NOx conversion 

capability. 

* * * * 

(1.2.3) Other Aftertreatment Assistance Functions. Additionally, for 2010 and 

subsequent model year vehicles, the catalyst(s) shall be monitored for 

other aftertreatment assistance functions: 

(A) For catalysts used to generate an exotherm to assist PM filter 

regeneration, the OBD II system shall detect a malfunction when the 

catalyst is unable to generate a sufficient exotherm to achieve 

regeneration of the PM filter. 

(B) For 2010 and subsequent model year passenger cars, light-duty trucks, 

and MDPVs certified to a chassis dynamometer tailpipe emission standard 
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and 2013 and subsequent model year medium-duty vehicles (including 

MDPVs) certified to an engine dynamometer tailpipe emission standard,

Ffor catalysts used to generate a feedgas constituency to assist SCR 

systems (e.g., to increase NO2 concentration upstream of an SCR 

system), the OBD II system shall detect a malfunction when the catalyst is 

unable to generate the necessary feedgas constituents for proper SCR 

system operation. 

(C) For catalysts located downstream of a PM filter and used to convert 

NMHC emissions during PM filter regeneration, the OBD II system shall 

detect a malfunction when the catalyst has no detectable amount of 

NMHC conversion capability. 

(D) For catalysts located downstream of an SCR system (e.g., and used to 

prevent ammonia slip), the OBD II system shall detect a malfunction when

the catalyst has no detectable amount of NMHC, CO, NOx, or PM 

conversion capability. Monitoring of the catalyst shall not be required if 

there is no measurable emission impact on the criteria pollutants (i.e., 

NMHC, CO, NOx, and PM) during any reasonable driving condition where 

the catalyst is most likely to affect criteria pollutants (e.g., during 

conditions most likely to result in ammonia generation or excessive 

reductant delivery). 

* * * * 

(3) MISFIRE MONITORING 

* * * * 

(3.2) Malfunction Criteria: 

* * * * 

(3.2.4) For multiple cylinder misfire situations that result in a misfire rate greater 

than or equal to 50 percent of all engine firings, the OBD II system shall 

only be required to detect a misfire malfunction for situations that are 

caused by a single component failure.

* * * * 

(4) FUEL SYSTEM MONITORING 

* * * * 

(4.2) Malfunction Criteria: 

* * * * 

(4.2.5) For purposes of determining the fuel system malfunction criteria in 

sections (ef)(4.2.1) through (4.2.3) for medium-duty vehicles (including 

MDPVs) certified to an engine dynamometer tailpipe emission standard, 

the manufacturer shall do the following:

(A) For 2004 through 2012 model year vehicles, the malfunction criteria shall 

be established by using a fault that affects either a single injector or all 

injectors equally.
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(B) For 2013 and subsequent model year vehicles, for section (ef)(4.2.1), the 

malfunction criteria shall be established by using a fault that affects all 

injectors equally. Additionally, for systems that have single component 

failures which could affect a single injector (e.g., systems that build 

injection pressure within the injector that could have a single component 

pressure fault caused by the injector itself), the malfunction criteria shall 

also be established by using a fault that affects a single injector.

(C) For 2013 and subsequent model year vehicles, for sections (ef)(4.2.2) 

through (4.2.3), the malfunction criteria shall be established by both (1) a 

fault that affects all the injectors equally and (2) a fault that affects only 

one injector.

(4.3) Monitoring Conditions: 

(4.3.1) Except as provided in sections (ef)(4.3.2) and (ef)(4.3.4), Tthe OBD II 

system shall monitor continuously for malfunctions identified in sections 

(f)(4.2.1) and (f)(4.2.4) (i.e., fuel pressure control and feedback operation). 

(4.3.2) For fuel systems that achieve injection fuel pressure within the injector or 

increase pressure within the injector (e.g. in the injector of an amplified 

common rail system), manufacturers may request Executive Officer 

approval to define the monitoring conditions for malfunctions identified in 

sections (ef)(4.2.1) in accordance with sections (d)(3.1) and (d)(3.2) (i.e., 

minimum ratio requirements). The Executive Officer shall approve the 

monitoring conditions upon the manufacturer submitting data and/or 

analysis identifying all possible failure modes and the effect each has 

(e.g., failure modes and effects analysis) on fuel pressure across the 

entire range of engine operating conditions, and upon the Executive 

Officer determining based on the data and/or analysis that the monitoring 

conditions allow for robust detection of all causes of fuel pressure 

malfunctions.

* * * * 

(6) EXHAUST GAS RECIRCULATION (EGR) SYSTEM MONITORING 

* * * * 

(6.2) Malfunction Criteria: 

* * * * 

(6.2.5) EGR Cooler Performance: 

(A) The OBD II system shall detect a malfunction of the EGR cooler system 

cooler at or prior to a reduction from the manufacturer's specified cooling 

performance that would cause a vehicle’s NMHC, CO, NOx, or PM 

emissions to exceed the applicable emission levels specified in sections 

(f)(6.2.1)(A):.

* * * * 

(C) For purposes of determining the EGR cooler performance malfunction 

criteria in section (f)(6.2.5)(A) for EGR cooler systems that consist of more 

than one cooler (e.g., a pre-cooler and a main cooler, two or more coolers 

in series), the manufacturer shall submit an EGR cooler system aging and 
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monitoring plan to the Executive Officer for review and approval. The plan 

shall include the description and location of each component, the 

monitoring strategy for each component and combination of components, 

and the method for determining the malfunction criteria of section 

(e)(3.2.5)(A) (f)(6.2.5)(A) including the deterioration/aging process. 

Executive Officer approval of the plan shall be based on the 

representativeness of the aging to real world EGR cooler system 

component deterioration under normal and malfunctioning engine 

operating conditions and the effectiveness of the method used to 

determine the malfunction criteria of section (e)(3.2.5)(A) (f)(6.2.5)(A).

* * * * 

(6.3) Monitoring Conditions: 

(6.3.1) For malfunctions identified in sections (f)(6.2.1) and (f)(6.2.2) (i.e., EGR 

low and high flow) manufacturers shall, manufacturers shall define 

monitoring conditions: 

(A) For 2004 through 2009 model year vehicles, Define monitoring conditions

in accordance with sections (d)(3.1) and (d)(3.2) (i.e., minimum ratio 

requirements) for 2004 through 2009 model year vehicles. For purposes 

of tracking and reporting as required in section (d)(3.2.2), all monitors 

used to detect malfunctions identified in sections (f)(6.2.1) and (f)(6.2.2) 

shall be tracked separately but reported as a single set of values as 

specified in section (d)(5.2.2); 

(B) Except as provided in section (ef)(6.3.5), ensure that monitoring is

Cconducted continuously for all 2010 and subsequent model year 

vehicles. 

* * * * 

(7) BOOST PRESSURE CONTROL SYSTEM MONITORING 

* * * * 

(7.2) Malfunction Criteria: 

* * * * 

(7.2.3) VGT sSlow response: 

(A) For 2010 through 2012 model year vehicles equipped with variable 

geometry turbochargers (VGT), Tthe OBD II system shall detect a 

malfunction at or prior to any failure or deterioration in the capability of the 

VGT system to achieve the commanded turbocharger geometry within a 

manufacturer-specified time that would cause a vehicle's NMHC, CO, 

NOx, or PM emissions to exceed the applicable emission levels specified 

in sections (f)(7.2.1)(A). For vehicles in which no failure or deterioration of 

the VGT system response could result in a vehicle’s emissions exceeding 

these levels, the OBD II system shall detect a malfunction of the VGT 

system when proper functional no detectable response of the system to 

computer a change in commandsed turbocharger geometry does not

occurs.

* * * * 
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(7.3) Monitoring Conditions: 

(7.3.1) Except as provided in section (ef)(7.3.4), Tthe OBD II system shall monitor 

continuously for malfunctions identified in sections (f)(7.2.1), (7.2.2), and 

(7.2.5) (i.e., over and under boost, feedback control). 

* * * * 

(8) NOx ADSORBER MONITORING 

* * * * 

(8.3) Monitoring Conditions: 

* * * * 

(8.3.2) Except as provided in section (ef)(8.3.3), Tthe OBD II system shall monitor 

continuously for malfunctions identified in sections (f)(8.2.2) and (8.2.3) 

(e.g., injection function, feedback control). 

* * * * 

(9) PARTICULATE MATTER (PM) FILTER MONITORING 

* * * * 

[Note: No 15-day changes are proposed for the following sections (f)(9.2.1), (f)(9.2.4), 

and (f)(9.2.5) however the regulatory text was included since it is referenced in the 

changes proposed above for section (d)(4.3.2)(G).] 

* * * * 

(9.2) Malfunction Criteria: 

(9.2.1) Filtering Performance: 

(A) The OBD II system shall detect a malfunction prior to a decrease in the 

filtering capability of the PM filter that would cause a vehicle's PM 

emissions to exceed: 

(i) For passenger cars, light-duty trucks, and MDPVs certified to a chassis 

dynamometer tailpipe emission standard: 

a. 5.0 times the applicable FTP standard for 2004 through 2009 model 

year vehicles; 

b. 4.0 times the applicable FTP standard for 2010 through 2012 model 

year vehicles; and 

c. 1.75 times the applicable FTP standard for 2013 and subsequent 

model year vehicles. 

(ii) For medium-duty vehicles (including MDPVs) certified to an engine 

dynamometer tailpipe emission standard: 

a. 0.09 g/bhp-hr PM as measured from an applicable cycle emission 

test for 2004 through 2009 model year vehicles; 

b. 0.057 g/bhp-hr PM as measured from an applicable cycle emission 

test for 2010 through 2012 model year vehicles; and

c. 0.03 g/bhp-hr PM as measured from an applicable cycle emission 

test for 2013 and subsequent model year vehicles. 

(B) If no failure or deterioration of the PM filtering performance could result in 

a vehicle’s PM emissions exceeding the applicable malfunction criteria 
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specified in section (f)(9.2.1)(A), the OBD II system shall detect a 

malfunction when no detectable amount of PM filtering occurs. 

* * * * 

(9.2.4) NMHC conversion: For 2010 and subsequent model year vehicles

passenger cars, light-duty trucks, and MDPVs certified to a chassis 

dynamometer tailpipe emission standard and 2013 and subsequent model 

year medium-duty vehicles (including MDPVs) certified to an engine 

dynamometer tailpipe emission standard with catalyzed PM filters that 

convert NMHC emissions, the OBD II system shall monitor the catalyst 

function of the PM filter and detect a malfunction when the NMHC 

conversion capability decreases to the point that NMHC emissions exceed 

the applicable emission levels specified in section (f)(9.2.2)(A). If no 

failure or deterioration of the NMHC conversion capability could result in a 

vehicle’s NMHC emissions exceeding these emission levels, the OBD II 

system shall detect a malfunction when the system has no detectable 

amount of NMHC conversion capability. 

(9.2.5) Missing substrate: The OBD II system shall detect a malfunction if either 

the PM filter substrate is completely destroyed, removed, or missing, or if 

the PM filter assembly is replaced with a muffler or straight pipe. 

* * * * 

(17) EXCEPTIONS TO MONITORING REQUIREMENTS 

* * * * 

(17.6) A manufacturer may request Executive Officer approval to disable monitors 

that can be affected by PTO activation on vehicles designed to accommodate 

the installation of PTO units (as defined in section (c)).

(17.6.1) Except as allowed in section (g)(17.6.2) below, a manufacturer may 

request Executive Officer approval to disable an affected monitor provided 

disablement occurs only while the PTO unit is active and the OBD II 

readiness status (specified under section (g)(4.1)) and PTO activation time 

are appropriately tracked and erased as described in this section. The 

Executive Officer shall approve the request for disablement based on the 

manufacturer’s demonstration that the affected monitor cannot robustly 

detect malfunctions (e.g., cannot avoid false passes or false indications of 

malfunctions) while the PTO unit is active. The OBD II system shall track 

the cumulative engine runtime with PTO active and clear OBD II readiness 

status (i.e., set all monitors to indicate “not complete”) no later than the 

start of the next ignition cycle if 750 minutes of cumulative engine runtime 

with PTO active has occurred since the last time the affected monitor has 

determined the component or system monitored by the affected monitor is 

or is not malfunctioning (i.e., has completed). The PTO timer shall pause 

whenever PTO changes from active to not active and resume counting 

when PTO is re-activated. The timer shall be reset to zero after the 

affected monitor has completed and no later than the start of the next 

ignition cycle. Once the PTO timer has reached 750 minutes and the 
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OBD II readiness status has been cleared, the PTO timer may not cause 

the OBD system to clear the readiness status again until after the PTO 

timer has reset to zero (after the monitor has completed) and again 

reached 750 minutes.

(17.6.2) In lieu of requesting Executive Officer approval for disabling an affected 

monitor according to section (f)(17.6.1) above, Aa manufacturer may 

disable affected monitoring systems in vehicles designed to accommodate 

the installation of Power Take-Off (PTO) units (as defined in section 

(c))monitors, provided disablement occurs only while the PTO unit is 

active, and the OBD II readiness status is cleared by the on-board 

computer (i.e., all monitors set to indicate “not complete”) while the PTO 

unit is activated (see section (g)(4.1) below). If the disablement occurs, 

the readiness status may be restored to its state prior to PTO activation 

when the disablement ends. 

* * * * 

(g) STANDARDIZATION REQUIREMENTS. 

* * * * 

(6) Engine Run Time Tracking Requirements: 

(6.1) For all 2010 and subsequent model year medium-duty vehicles equipped with 

diesel engines, manufacturers shall implement software algorithms to 

individually track and report in a standardized format the engine run time 

while being operated in the following conditions: 

(6.1.1) Total engine run time; 

(6.1.2) Total idle run time (with “idle” defined as accelerator pedal released by 

driver, vehicle speed less than or equal to one mile per hour, engine 

speed greater than or equal to 50 to 150 rpm below the normal warmedup idle speed (as determined in the drive position for vehicles equipped 

with an automatic transmission), and PTO not active), and either vehicle 

speed less than or equal to one mile per hour or engine speed less than or 

equal to 200 rpm above normal warmed-up idle); 

(6.1.3) Total run time with PTO active. 

(6.1.4) Total run time with EI-AECD #1active; 

(6.1.5) Total run time with EI-AECD #2 active; and so on up to 

(6.1.6) Total run time with EI-AECD #n active. 

(6.1.7) For 2010 through 2012 model year vehicles, manufacturers may define 

“idle” in section (g)(6.1.2) above as accelerator pedal released by driver, 

vehicle speed less than or equal to one mile per hour, and PTO not active.

* * * * 
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§1971.1. On-Board Diagnostic System Requirements -- 2010 and Subsequent 

Model-Year Heavy-Duty Engines. 

* * * * 

(c) DEFINITIONS 

* * * * 

“Start of production” is the time when the manufacturer has produced two percent 

of the projected volume for the engine or vehicle, whichever is being evaluated in 

accordance with specified in sections (k) and (l). 

* * * * 

(d) GENERAL REQUIREMENTS 

* * * * 

(2) MIL and Fault Code Requirements. 

* * * * 

(2.3) MIL Extinguishing and Fault Code Erasure Protocol.

* * * * 

(2.3.2) For vehicles using the SAE J1939 protocol for the standardized functions 

required in section (h): 

* * * * 

(D) Erasing a permanent fault code. The OBD system shall erase a 

permanent fault code only if either of the under the following conditions

occur:

* * * * 

(ii) Subsequent to a clearing of theIf all fault information in the on-board 

computer has been cleared (i.e., through the use of a scan tool or 

battery disconnect) and the OBD system is not commanding the MIL 

on, the diagnostic for the malfunction that caused the permanent fault 

code to be stored has fully executed (i.e., has executed the minimum 

number of checks necessary for MIL illumination) and determined the 

malfunction is no longer present.:

* * * * 

b. If the monitor of the malfunction that caused the permanent fault 

code to be stored is not subject to the minimum ratio requirements 

of section (d)(3.2) (e.g., continuous diesel fuel system monitors, 

comprehensive component circuit continuity monitors), the OBD 

system shall erase the permanent fault code at the end of a driving 

cycle if:

1. The monitor has run and made one or more determinations 

during a driving cycle that the malfunction of the component or 

the system is not present and has not made any determinations 

within the same driving cycle that the malfunction is present;

2. The monitor has not made any determinations that the 

malfunction is present subsequent to the most recent driving 
13

cycle in which the criteria of section (d)(2.3.2)(D)(ii)b.1. are met; 

and

3. The following criteria are satisfied on any single driving cycle 

(which may be a different driving cycle than that in which the 

criteria of section (d)( 2.3.2)(D)(ii)b.1. are satisfied):

i. Cumulative time since engine start is greater than or equal to 

600 seconds;

ii. Cumulative gasoline engine operation at or above 25 miles 

per hour or diesel engine operation at or above 1150 rpm, 

either of which occurs for greater than or equal to 300 

seconds; and

iii. Continuous vehicle operation at idle (i.e., accelerator pedal 

released by driver and either vehicle speed less than or 

equal to one mile per hour or engine speed less than or 

equal to 200 rpm above normal warmed-up idle (as

determined in the drive position for vehicles equipped with 

an automatic transmission)) for greater than or equal to 30 

seconds.; and

iv. The monitor has not made any determinations that the 

malfunction is present.

4. Monitors required to use “similar conditions” as defined in section 

(c) to store and erase pending and confirmed/MIL-on fault codes 

may not require that the similar conditions be met prior to 

erasure of the permanent fault code.

 * * * * 

(4) In-Use Monitor Performance Ratio Definition. 

* * * * 

(4.3) Denominator Specifications 

* * * * 

(4.3.2) Specifications for incrementing: 

* * * * 

(B) The denominator for each monitor shall be incremented within 10 seconds 

if and only if the following criteria are satisfied on a single driving cycle: 

(i) Cumulative time since start of driving cycle is greater than or equal to 

600 seconds while at an elevation of less than 8,000 feet above sea 

level and at an ambient temperature of greater than or equal to 20 

degrees Fahrenheit; 

(ii) Cumulative gasoline engine operation at or above 25 miles per hour or 

diesel engine operation at or above 15% calculated load1150 rpm, 

either of which occurs for greater than or equal to 300 seconds while at 

an elevation of less than 8,000 feet above sea level and at an ambient 

temperature of greater than or equal to 20 degrees Fahrenheit; and 

(iii) Continuous vehicle operation at idle (i.e.g., accelerator pedal released 

by driver and either vehicle speed less than or equal to one mile per 
14

hour or engine speed less than or equal to 200 rpm above normal 

warmed-up idle (as determined in the drive position for vehicles 

equipped with an automatic transmission)) for greater than or equal to 

30 seconds while at an elevation of less than 8,000 feet above sea 

level and at an ambient temperature of greater than or equal to 20 

degrees Fahrenheit. 

(iv) For 2010 through 2012 model year diesel engines, manufacturers may 

use diesel engine operation at or above 15% calculated load in lieu of 

1150 rpm for the criterion in section (d)(4.3.2)(B)(ii) above.

* * * * 

(E) In addition to the requirements of section (d)(4.3.2)(B) above, the 

denominator(s) for the following monitors of output components (except 

those operated only at engine start-up and subject to the requirements of 

the previous section (d)(4.3.2)(D)) shall be incremented if and only if the 

component is commanded to function (e.g., commanded “on”, “open”, 

“closed”, “locked”) on two or more occasions for greater than two seconds

during the driving cycle or for a cumulative time greater than or equal to 10 

seconds, whichever occurs first: 

(i) Variable valve timing and/or control system (sections (e)(10) or (f)(9)) 

(ii) “Other emission control systems” (section (g)(4)) 

(iii) Comprehensive component output component (section (g)(3)) (e.g., 

turbocharger waste-gates, variable length manifold runners) 

As an alternative, in addition to the requirements of section (d)(4.3.2)(B), 

manufacturers may use the criteria specified in title 13, CCR section 

1968.2(d)(4.3.2)(F) in lieu of the criteria specified in section (d)(4.3.2)(E) 

above.

* * * * 

(G) For monitors of the following components or other emission controls that 

experience infrequent regeneration events, the manufacturer may request 

Executive Officer approval to use alternate or additional criteria to that set 

forth in section (d)(4.3.2)(B) above for incrementing the denominator. 

Executive Officer approval of the proposed criteria shall be based on the 

effectiveness of the proposed criteria in measuring the frequency of 

monitor operation relative to the amount of vehicle operationthe

denominator(s) shall be incremented by one if and only if, in addition to 

meeting during a driving cycle in which the following two criteria are met: 

(1) the requirements of section (d)(4.3.2)(B) are met on the current driving 

cycle, and (2) at least the number of minutes of cumulative engine run 

time since the denominator was last incremented is greater than or equal 

to 750 800 minutes of cumulative engine run time have occurred since the 

last time the denominator was incremented. The 750800-minute engine 

run time counter shall be reset to zero and begin counting again after the 

denominator has been incremented and no later than the start of the next 

ignition cycle:

(i) Oxidation Diesel NMHC converting catalyst (section (e)(5.2.2)) 

(ii) Diesel NMHC converting catalyst other aftertreatment assistance 
15

functions (sections (e)(5.2.3)(B) and (D))

(iii) Particulate matter filters (sections (e)(8.2.1), (8.2.4), and (8.2.5)) 

As an alternative, for 2010 through 2012 model year engines, the 

manufacturer may request Executive Officer approval to use alternate or

additional criteria to that set forth in section (d)(4.3.2)(G) above for 

incrementing the denominator. Executive Officer approval of the proposed 

criteria shall be based on the effectiveness of the proposed criteria in 

measuring the frequency of monitor operation relative to the amount of 

vehicle operation.

(H) For 2013 and subsequent model year engines, Iin addition to the 

requirements of section (d)(4.3.2)(B) above, the denominator(s) for the 

following monitors shall be incremented if and only if a regeneration event 

is commanded for a time greater than or equal to 10 seconds:

(i) Diesel NMHC converting catalyst other aftertreatment assistance 

functions (sections (e)(5.2.3)(A) and (C))

(ii) PM filter incomplete regeneration (section (e)(8.2.3))

(iii) PM filter active/intrusive injection (section (e)(8.2.6))

* * * * 

(e) MONITORING REQUIREMENTS FOR DIESEL/COMPRESSION-IGNITION 

ENGINES 

(1) FUEL SYSTEM MONITORING 

* * * * 

[Note: No 15-day changes are proposed for the following section (e)(1.2.4) however the 

regulatory text was included since it is referenced in the changes proposed below for 

sections (h)(4.1.4) and (h)(4.5.7).] 

* * * * 

(1.2) Malfunction Criteria: 

* * * * 

(1.2.4) Feedback control: Except as provided for in section (e)(1.2.5), if the 

engine is equipped with feedback or feed-forward control of the fuel 

system (e.g., feedback control of pressure or pilot injection quantity), the 

OBD system shall detect a malfunction: 

(A) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(B) If a failure or deterioration causes open loop or default operation; or 

(C) If feedback the control system has used up all of the adjustment allowed 

by the manufacturer or reached its maximum authority and cannot achieve 

the target. 

* * * * 

(2) MISFIRE MONITORING 

* * * * 
16

(2.2) Malfunction Criteria: 

* * * * 

(2.2.4) For multiple cylinder misfire situations that result in a misfire rate greater 

than or equal to 50 percent of all engine firings, the OBD system shall only 

be required to detect a misfire malfunction for situations that are caused 

by a single component failure. 

* * * * 

(3) EXHAUST GAS RECIRCULATION (EGR) SYSTEM MONITORING 

* * * * 

(3.2) Malfunction Criteria: 

* * * * 

(3.2.4) Feedback control: Except as provided for in section (e)(3.2.67), if the 

engine is equipped with feedback or feed-forward control of the fuel 

system (e.g., feedback control of flow, valve position, pressure differential 

across the valve via intake throttle or exhaust backpressure), the OBD 

system shall detect a malfunction: 

(A) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(B) If a failure or deterioration causes open loop or default operation; or 

(C) If feedback the control system has used up all of the adjustment allowed 

by the manufacturer or reached its maximum authority and cannot achieve 

the target. 

* * * * 

[Note: No 15-day changes are proposed for the following sections (e)(4) through (e)(9) 

however the regulatory text was included since it is referenced in the changes proposed 

below for sections (h)(4.1.4) and (h)(4.5.7).] 

* * * * 

(4) BOOST PRESSURE CONTROL SYSTEM MONITORING 

* * * * 

(4.2) Malfunction Criteria: 

* * * * 

(4.2.5) Feedback control: Except as provided for in section (e)(4.2.6), if the 

engine is equipped with feedback or feed-forward control of the boost 

pressure system (e.g., control of VGT variable geometry turbocharger

position, turbine speed, manifold pressure) the OBD system shall detect a 

malfunction: 

(A) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(B) If a failure or deterioration causes open loop or default operation; or 

(C) If feedback the control system has used up all of the adjustment allowed 

by the manufacturer or reached its maximum authority and cannot achieve 

the target. 
17

* * * * 

(5) NON-METHANE HYDROCARBON (NMHC) CONVERTING CATALYST

MONITORING 

* * * * 

(5.2) Malfunction Criteria: 

* * * * 

(5.2.2) Conversion Efficiency: 

(A) For 2010 through 2012 model year engines, Tthe OBD system shall 

detect an NMHC catalyst malfunction when the catalyst conversion 

capability decreases to the point that NMHC emissions exceed 2.0 times 

any of the applicable standards. 

(B) For 2013 and subsequent model year engines, the OBD system shall 

detect an NMHC catalyst malfunction when the catalyst conversion 

capability decreases to the point that NMHC emissions exceed 2.0 times 

any of the applicable standards or NOx emissions exceed any of the 

applicable standards by more than 0.2 g/bhp-hr (e.g., cause emissions to 

exceed 0.4 g/bhp-hr if the emission standard is 0.2 g/bhp-hr). 

(C) If no failure or deterioration of the catalyst NMHC conversion capability 

could result in an engine’s NMHC or NOx emissions exceeding 2.0 times 

any of the applicable standardsmalfunction criteria of section (e)(5.2.2), 

the OBD system shall detect a malfunction when the catalyst has no 

detectable amount of NMHC or NOx conversion capability. 

(5.2.3) Other Aftertreatment Assistance Functions: 

(A) For catalysts used to generate an exotherm to assist PM filter 

regeneration, the OBD system shall detect a malfunction when the 

catalyst is unable to generate a sufficient exotherm to achieve 

regeneration of the PM filter. 

(B) For 2013 and subsequent model year engines, Ffor catalysts used to 

generate a feedgas constituency to assist SCR systems (e.g., to increase 

NO2 concentration upstream of an SCR system), the OBD system shall 

detect a malfunction when the catalyst is unable to generate the 

necessary feedgas constituents for proper SCR system operation. 

(C) For catalysts located downstream of a PM filter and used to convert 

NMHC emissions during PM filter regeneration, the OBD system shall 

detect a malfunction when the catalyst has no detectable amount of 

NMHC conversion capability. 

(D) For catalysts located downstream of an SCR system (e.g., to prevent 

ammonia slip), the OBD system shall detect a malfunction when the 

catalyst has no detectable amount of NMHC, CO, NOx, or PM conversion 

capability. Monitoring of the catalyst is not required if there is no 

measurable emission impact on the criteria pollutants (i.e., NMHC, CO, 

NOx, and PM) during any reasonable driving condition where the catalyst 

is most likely to affect criteria pollutants (e.g., during conditions most likely 

to result in ammonia generation or excessive reductant delivery).
18

* * * * 

(6) OXIDES OF NITROGEN (NOx) CONVERTING CATALYST MONITORING 

* * * * 

(6.2) Malfunction Criteria: For purposes of section (e)(6), each catalyst in a series 

configuration that converts NOx shall be monitored either individually or in 

combination with others. 

* * * * 

(6.2.2) Selective Catalytic Reduction (SCR) or Other Active/Intrusive Reductant 

Injection System Performance: 

* * * * 

(D) Feedback control: Except as provided for in section (e)(6.2.2)(E), if the 

engine is equipped with feedback or feed-forward control of the reductant 

injection, the OBD system shall detect a malfunction: 

(i) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(ii) If a failure or deterioration causes open loop or default operation; or 

(iii) If the feedback control system has used up all of the adjustment 

allowed by the manufacturer or reached its maximum authority and 

cannot achieve the target. 

* * * * 

(7) NOx ADSORBER MONITORING 

* * * * 

(7.2) Malfunction Criteria: 

* * * * 

(7.2.3) Feedback control: Except as provided for in section (e)(7.2.4), if the 

engine is equipped with feedback or feed-forward control of the NOx 

adsorber or active/intrusive injection system (e.g., feedback control of 

injection quantity, time), the OBD system shall detect a malfunction: 

(A) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(B) If a failure or deterioration causes open loop or default operation; or 

(C) If feedback the control system has used up all of the adjustment allowed 

by the manufacturer or reached its maximum authority and cannot achieve 

the target. 

* * * * 

(8) PARTICULATE MATTER (PM) FILTER MONITORING 

* * * * 

(8.2) Malfunction Criteria: 

* * * * 
19

(8.2.7) Feedback Control: Except as provided for in section (e)(8.2.8), if the 

engine is equipped with feedback or feed-forward control of the PM filter 

regeneration (e.g., feedback control of oxidation catalyst inlet temperature, 

PM filter inlet or outlet temperature, in-cylinder or in-exhaust fuel injection), 

the OBD system shall detect a malfunction: 

(A) If the system fails to begin feedback control within a manufacturer 

specified time interval; 

(B) If a failure or deterioration causes open loop or default operation; or 

(C) If feedback the control system has used up all of the adjustment allowed 

by the manufacturer or reached its maximum authority and cannot achieve 

the target. 

* * * * 

(9) EXHAUST GAS SENSOR MONITORING 

* * * * 

(9.2) Malfunction Criteria: 

(9.2.1) Air-Fuel Ratio Sensors: 

(A) For sensors located upstream of the exhaust aftertreatment: 

* * * * 

(iii) Feedback faults: The OBD system shall detect a malfunction of the 

sensor when a sensor failure or deterioration causes an emission 

control system (e.g., EGR, SCR, or NOx adsorber) to stop using that 

sensor as a feedback or feed-forward input (e.g., causes default or 

open-loop operation). 

* * * * 

(B) For sensors located downstream of the exhaust aftertreatment: 

* * * * 

(iii) Feedback faults: The OBD system shall detect a malfunction of the 

sensor when a sensor failure or deterioration causes an emission 

control system (e.g., EGR, SCR, or NOx adsorber) to stop using that 

sensor as a feedback or feed-forward input (e.g., causes default or 

open-loop operation). 

* * * * 

(9.2.2) NOx and PM sensors: 

* * * * 

(C) Feedback faults: The OBD system shall detect a malfunction of the 

sensor when a sensor failure or deterioration causes an emission control 

system (e.g., EGR, SCR, or NOx adsorber) to stop using that sensor as a 

feedback or feed-forward input (e.g., causes default or open-loop 

operation). 

* * * * 
20

(f) MONITORING REQUIREMENTS FOR GASOLINE/SPARK-IGNITED ENGINES 

(1) FUEL SYSTEM MONITORING 

* * * * 

(1.2) Malfunction Criteria: 

(1.2.1) The OBD system shall detect a malfunction of the fuel delivery system 

(including feedback control based on a secondary oxygen sensor) when:

(A) tThe fuel delivery system is unable to maintain an engine's emissions at or 

below 1.5 times the applicable standards; or.

(B) If equipped, the feedback control based on a secondary oxygen or 

exhaust gas sensor is unable to maintain a vehicle’s emissions (except as 

a result of a malfunction specified in section (f)(1.2.1)(C)) at or below 1.5 

times any of the applicable standards; or

(C) Except as required in section (f)(1.2.6), fFor 2014 and subsequent model 

year vehicles, an air-fuel ratio cylinder imbalance (e.g., the air-fuel ratio in 

one or more cylinders is different than the other cylinders due to a cylinder 

specific malfunction such as an intake manifold leak at a particular 

cylinder, fuel injector problem, an individual cylinder EGR runner flow 

delivery problem, an individual variable cam lift malfunction such that an 

individual cylinder is operating on the wrong cam lift profile, or other 

similar problems) occurs in one or more cylinders such that the fuel 

delivery system is unable to maintain a vehicle’s emissions at or below: 

3.0 times the applicable standards for the 2014 through 2016 model years; 

and 1.5 times the applicable FTP standards for all 2017 and subsequent 

model year vehicles. 

(1.2.2) Except as provided for in section (f)(1.2.3) below, if the engine is equipped 

with adaptive feedback control, the OBD system shall detect a malfunction 

when the adaptive feedback control has used up all of the adjustment 

allowed by the manufacturer. 

* * * * 

(1.2.4) The OBD system shall detect a malfunction whenever the fuel control 

system fails to enter closed-loop operation within an Executive Officerapproved time interval after engine start. Executive Officer approval of the 

time interval shall be granted upon determining that the data and/or 

engineering evaluation submitted by the manufacturer supports the 

specified times. 

(1.2.5) For engines that employ engine shutoff strategies that do not require the 

vehicle operator to restart the engine to continue driving (e.g., hybrid bus 

with engine shutoff at idle), the OBD system shall detect whenever the fuel 

control system fails to enter closed-loop operation within an Executive 

Officer-approved time interval after an engine restart. Executive Officer 

approval of the time interval shall be granted upon determining that the 

data and/or engineering evaluation submitted by the manufacturer 

supports the specified times.

(1.2.5) Manufacturers may adjust the malfunction criteria and/or monitoring 

conditions to compensate for changes in altitude, for temporary 
21

introduction of large amounts of purge vapor, or for other similar 

identifiable operating conditions when they occur.

(1.2.6) Notwithstanding the phase-in specified in section (f)(1.2.1)(C), if a vehicle

is equipped with separate EGR flow delivery passageways (internal or 

external) that deliver EGR flow to individual cylinders (e.g., an EGR 

system with individual delivery pipes to each cylinder), the OBD system 

shall monitor the fuel delivery system for malfunctions specified in section 

(f)(1.2.1)(C) on all 2014 and subsequent model year vehicles so equipped.

(1.3) Monitoring Conditions: 

(1.3.1) Except as provided in section (f)(1.3.5), Tthe OBD system shall monitor

fuel system shall be monitored continuously for the presence of a

malfunctions identified in sections (f)(1.2.1)(A), and (f)(1.2.1)(B), and 

(f)(1.2.2) (e.g.i.e., fuel delivery system, secondary feedback control,

adaptive feedback control). 

* * * * 

(8) EXHAUST GAS SENSOR MONITORING 

* * * * 

[Note: No 15-day changes are proposed for the following sections (f)(8.2.1) and 

(f)(8.2.2) however the regulatory text was included since it is referenced in the changes 

proposed below for sections (h)(4.1.4) and (h)(4.5.7).] 

* * * * 

(8.2) Malfunction Criteria: 

(8.2.1) Primary Sensors: 

* * * * 

(C) The OBD system shall detect a malfunction of the exhaust gasoxygen

sensor when a sensor failure or deterioration causes the fuel system to 

stop using that sensor as a feedback input (e.g., causes default or openloop operation) or causes the fuel system to fail to enter closed-loop 

operation within a manufacturer-specified time interval. 

* * * * 

(8.2.2) Secondary Sensors: 

* * * * 

(E) The OBD system shall detect a malfunction of the exhaust gasoxygen

sensor when a sensor failure or deterioration causes the fuel system (e.g., 

fuel control) to stop using that sensor as a feedback input (e.g., causes 

default or open-loop operation). 

* * * * 

(g) MONITORING REQUIREMENTS FOR ALL ENGINES 

* * * * 

(3) COMPREHENSIVE COMPONENT MONITORING 

(3.1) Requirement: 
22

(3.1.1) Except as provided in sections (g)(3.1.4), (g)(3.1.5), (g)(3.1.6), and (g)(4), 

the OBD system shall monitor for malfunction any electronic engine 

component/system not otherwise described in sections (e)(1) through 

(g)(2) that either provides input to (directly or indirectly) or receives 

commands from the on-board computer(s), and: (1) can affect emissions 

during any reasonable in-use driving condition, or (2) is used as part of the 

diagnostic strategy for any other monitored system or component. 

* * * * 

(3.1.3) Manufacturers shall monitor for malfunction electronic powertrain input or 

output components/systems associated with an electronic transfer case, 

electronic power steering system, or other components that are driven by 

the engine and not related to the control of fueling, air handling, or 

emissions only if the transfer case component or system is used as part of 

the diagnostic strategy for any other monitored system or componentFor 

purposes of section (g)(3), ”electronic engine components/systems” does 

not include components that are driven by the engine and are not related 

to the control of the fueling, air handling, or emissions of the engine (e.g., 

PTO components, air conditioning system components, and power 

steering components). 

* * * * 

(3.1.6) For OBD systems that receive vehicle speed information from a

transmission control unit and use vehicle speed as part of the diagnostic 

strategy for any other OBD monitored system or component:

(A) The OBD system shall monitor the vehicle speed information to the extent 

feasible in accordance with the requirements of section (g)(3); 

(B) The OBD system shall detect a fault and illuminate the MIL when the OBD 

system is unable to properly receive the vehicle speed information; and

(C) If the transmission control unit monitors the vehicle speed information and

indicates an error of the information to the OBD system (e.g., valid vehicle 

speed data is no longer available), the OBD system shall handle the error 

indication as a default mode of operation subject to the MIL illumination 

requirements under section (d)(2.2).

* * * * 

(5) EXCEPTIONS TO MONITORING REQUIREMENTS 

* * * * 

(5.6) A manufacturer may request Executive Officer approval to disable monitors 

that can be affected by PTO activation on engines or vehicles designed to 

accommodate the installation of PTO units (as defined in section (c)).

(5.6.1) Except as allowed in section (g)(5.6.2) below, a manufacturer may request 

Executive Officer approval to disable an affected monitor provided 

disablement occurs only while the PTO unit is active and the OBD 

readiness status (specified under section (h)(4.1)) and PTO activation time 

are appropriately tracked and erased as described in this section. The 

Executive Officer shall approve the request for disablement based on the 
23

manufacturer’s demonstration that the affected monitor cannot robustly 

detect malfunctions (e.g., cannot avoid false passes or false indications of 

malfunctions) while the PTO unit is active. The OBD system shall track 

the cumulative engine runtime with PTO active and clear OBD readiness 

status (i.e., set all monitors to indicate “not complete”) no later than the 

start of the next ignition cycle if 750 minutes of cumulative engine runtime 

with PTO active has occurred since the last time the affected monitor has 

determined the component or system monitored by the affected monitor is 

or is not malfunctioning (i.e., has completed). The PTO timer shall pause 

whenever PTO changes from active to not active and resume counting 

when PTO is re-activated. The timer shall be reset to zero after the 

affected monitor has completed and no later than the start of the next 

ignition cycle. Once the PTO timer has reached 750 minutes and the 

OBD readiness status has been cleared, the PTO timer may not cause the 

OBD system to clear the readiness status again until after the PTO timer 

has reset to zero (after the monitor has completed) and again reached 750 

minutes.

(5.6.2) For 2010 through 2012 model year engines, in lieu of requesting Executive 

Officer approval for disabling an affected monitor according to section 

(g)(5.6.1) above, Aa manufacturer may disable affected monitoring

monitors systems in vehicles designed to accommodate the installation of 

PTO units (as defined in section (c)), provided disablement occurs only 

while the PTO unit is active, and the OBD readiness status is cleared by 

the on-board computer (i.e., all monitors set to indicate “not complete”) 

while the PTO unit is activated (see section (h)(4.1) below). If the 

disablement occurs, the readiness status may be restored to its state prior 

to PTO activation when the disablement ends. 

* * * * 

(h) STANDARDIZATION REQUIREMENTS 

* * * * 

(4) Required Emission Related Functions: 

* * * * 

(4.1) Readiness Status: In accordance with SAE J1979/J1939-73 specifications, 

the OBD system shall indicate “complete” or “not complete” since the fault 

memory was last cleared for each of the installed monitored components and

systems identified in sections (e)(1) through (f)(9), and (g)(3) except (e)(11) 

and (f)(4). The readiness status for Aall components or systems identified in 

(f)(1), (f)(2), or and (g)(3) that are monitored continuously shall always 

indicate “complete”. The readiness status for all other Ccomponents or 

systems that are not subject to continuous monitoring shall immediately 

indicate “complete” upon the respective diagnosticmonitor(s) (except those 

monitors specified under section (h)(4.1.4) below) being fully executed and

determining that the component or system is not malfunctioning. The 

readiness status for Aa component or system shall also indicate “complete” if 
24

after the requisite number of decisions necessary for determining MIL status 

has been fully executed, the monitor indicates a malfunction for the 

component or system. The readiness status for each of the monitored 

components or systems shall indicate “not complete” whenever fault memory 

has been cleared or erased by a means other than that allowed in section 

(d)(2). Normal vehicle shut down (i.e., key off, engine off) may not cause the 

readiness status to indicate “not complete”. 

* * * * 

(4.1.4) Manufacturers are not required to use the following monitors in 

determining the readiness status for the specific component or system:

(A) Circuit and out-of-range monitors that are required to be continuous;

(B) Gasoline and diesel exhaust gas sensor feedback monitors specified in 

sections (e)(9.2.1)(A)(iii), (e)(9.2.1)(B)(iii), (e)(9.2.2)(C), (f)(8.2.1)(C), and 

(f)(8.2.2)(E); 

(C) Diesel feedback control monitors specified in sections (e)(1.2.4), 

(e)(3.2.4), (e)(4.2.5), (e)(6.2.2)(D), (e)(7.2.3), and (e)(8.2.7);

(D) Gasoline fuel system monitors specified in sections (f)(1.2.1)(A), 

(f)(1.2.1)(B), (f)(1.2.2), (f)(1.2.4), and (f)(1.2.5).

* * * * 

(4.5) Test Results:

* * * * 

(4.5.7) The requirements of section (h)(4.5) do not apply to continuous gasoline

fuel system monitorings specified under sections (f)(1.2.1)(A), (f)(1.2.1)(B),

(f)(1.2.2), (f)(1.2.4), and (f)(1.2.5), gasoline exhaust gas sensor 

monitorings specified under sections (e)(9.2.1)(A)(iii), (e)(9.2.1)(B)(iii), 

(e)(9.2.2)(C), (f)(8.2.1)(C), and (f)(8.2.2)(E), cold start emission reduction 

strategy monitorings, and continuous circuit monitoring, continuousand

out-of-range monitorings that are required to be continuous, and diesel 

feedback control monitorings specified under sections (e)(1.2.4), 

(e)(3.2.4), (e)(4.2.5), (e)(6.2.2)(D), (e)(7.2.3), and (e)(8.2.7). 

* * * * 

(4.7) Software Calibration Verification Number:

* * * * 

(4.7.4) (4.7.5) For purposes of Inspection and Maintenance (I/M) testing, 

manufacturers shall make the CVN and CAL ID combination information 

available for all vehicles in a standardized electronic format that allows for 

off-board verification that the CVN is valid and appropriate for a specific 

vehicle and CAL ID. The standardized electronic format is detailed in 

Attachment XX F of ARB Mail-Out #MSC XX-XX 09-22, Month Date, Year,

July 7, 2009, incorporated by reference. Manufacturers shall submit the 

CVN and CAL ID information to the Executive Officer not more than 25 

days after the close of a calendar quarter.

* * * * 

(4.8) Vehicle and Engine Identification Numbers: 

* * * * 
25

(4.8.2) (4.8.3) If the VIN or ESN is reprogrammable, all emission-related 

diagnostic information identified in section (h)(4.9.14.10.1) shall be erased 

in conjunction with reprogramming of the VIN or the ESN. 

* * * * 

(5) Tracking Requirements: 

* * * * 

(5.2) Engine Run Time Tracking Requirements: 

(5.2.1) For all gasoline and diesel engines, manufacturers shall implement 

software algorithms to individually track and report in a standardized 

format the engine run time while being operated in the following 

conditions: 

(A) Total engine run time; 

(B) Total idle run time (with “idle” defined as accelerator pedal released by 

driver, vehicle speed less than or equal to one mile per hour, engine 

speed greater than or equal to 50 to 150 rpm below the normal, warmedup idle speed (as determined in the drive position for vehicles equipped 

with an automatic transmission), and PTO not active), and either vehicle 

speed less than or equal to one mile per hour or engine speed less than or 

equal to 200 rpm above normal warmed-up idle), and; 

(C) Total run time with PTO active.;

(D) For 2013 and subsequent model year diesel engines only: 

(i) total run time with EI-AECD #1active;

(ii) total run time with EI-AECD #2 active; and so on up to

(iii) total run time with EI-AECD #n active.

* * * * 

(j) CERTIFICATION DOCUMENTATION 

* * * * 

(2.2) A table, in the standardized format detailed in Attachment A XX C of ARB 

Mail-Out #95-20XX-XX MSC 09-22, May 22, 1995 Month Date, Year, July 7, 

2009, incorporated by reference. 

* * * * 

(2.17) A checklist of all the malfunction criteria in sections (e),or (f), and (g) and the 

corresponding diagnostic noted by fault code for each malfunction criterion. 

The formats of the checklists are detailed in Attachments XX G and XX H of 

ARB Mail-Out #MSC XX-XX09-22, Month Date, Year, July 7, 2009,

incorporated by reference. 

* * * * 

(k) DEFICIENCIES 

* * * * 

(6) Request for retroactive deficiencies 

(6.1) During either the first 6 months after commencement of normal the start of 
26

engine production or the first 3 months after commencement of the start of 

vehicle production, whichever is later, manufacturers may request that the 

Executive Officer grant a deficiency and amend an engine’s certification to 

conform to the granting of the deficiencies for each aspect of the monitoring 

system: (a) identified by the manufacturer (during testing required by section 

(l)(2) or any other testing) to be functioning different than the certified system 

or otherwise not meeting the requirements of any aspect of section 1971.1; 

and (b) reported to the Executive Officer. If the Executive Officer grants the 

deficiency(ies) and amendsed the certification, their approval would be 

retroactive to the start of production all affected engines within the engine 

family. 

* * * * 

(l) PRODUCTION ENGINE/VEHICLE EVALUATION TESTING 

(1) Verification of Standardized Requirements. 

(1.1) Requirement: Manufacturers shall perform testing to verify that 2013 and 

subsequent model year production vehicles meet the requirements of section 

(h)(3) and (h)(4) relevant to proper communication of required emissionrelated messages to an SAE J1978/J1939 scan tool. 

(1.2) Selection of Test Vehicles: 

(1.2.1) Engine manufacturers shall perform this testing every model year on ten 

unique production vehicles (i.e., engine rating and chassis application 

combination) per engine family. If there are less than ten unique 

production vehicles for a certain engine family, the manufacturer shall test 

each unique production vehicle in that engine family. Manufacturers shall 

perform this testing within no later than either three months of after the 

start of engine production or one month of after the start of vehicle 

production, whichever is later. Manufacturers may request Executive 

Officer approval to group multiple production vehicles together and test 

one representative vehicle per group. The Executive Officer shall approve 

the request upon finding that the software and hardware designed to 

comply with the standardization requirements of section (h) (e.g., 

communication protocol message timing, number of supported data 

stream parameters, engine and vehicle communication network 

architecture) in the representative vehicle are identical to all others in the 

group and that any differences in the production vehicles are not relevant 

with respect to meeting the criteria in section (l)(1.4). 

* * * * 

(2) Verification of Monitoring Requirements. 

(2.1) Within No later than either the first six months of after the start of engine 

production or the first three months of after the start of vehicle production, 

whichever is later, manufacturers shall conduct a complete evaluation of the 

OBD system of one or more production vehicles (test vehicles) and submit 

the results of the evaluation to the Executive Officer. 

* * * * 
27

§1971.5. Enforcement of Malfunction and Diagnostic System Requirements for 

2010 and Subsequent Model-Year Heavy-Duty Engines. 

* * * * 

(d) Remedial Action. 

* * * * 

(2) Influenced OBD-Related Recalls. 

(A) Upon being notified by the Executive Officer, pursuant to section (b)(7)(G), 

that an engine class is equipped with a nonconforming OBD system, the 

manufacturer may, within 45 days from the date of service of such 

notification, elect to conduct an influenced OBD-related recall of all engines 

within the engine class for the purpose of correcting the nonconforming OBD 

systems. Upon such an election, the manufacturer shall, within 45 days from 

the date of such election, submit an influenced OBD-related recall plan for 

approval, as prescribed under section (e)(1) below.

* * * * 

(3) Ordered Remedial Action-Mandatory Recall. 

(A) Except as provided in sections (d)(3)(B) below, the Executive Officer shall 

order the recall and repair of all engines in an engine class that have been 

determined to be equipped with a nonconforming OBD system if enforcement 

testing conducted pursuant to sections (b) or (c) above or information 

received from the manufacturer indicates that: 

(i) For major monitors required to meet the in-use performance ratio pursuant 

to Cal. Code Regs., title 13, section 1971.1(d)(3.2) on 2016 and 

subsequent model year engines, the average in-use monitor performance 

ratio for one or more of the major monitors in the test sample group is less 

than or equal to 33.0 percent of the applicable required minimum ratio 

established in Cal. Code Regs., title 13, section 1968.2 1971.1(d)(3.2.2) 

(e.g., if the required ratio is 0.100, less than or equal to a ratio of 0.033) or 

66.0 percent or more of the vehicles in the test sample group have an inuse monitor performance ratio of less than or equal to 33.0 percent of the 

applicable required minimum ratio established in Cal. Code Regs., title 13, 

section 1968.2 1971.1(d)(3.2.2) for the same major monitor. 

* * * * 

(e) Requirements for Implementing Remedial Actions. 

* * * * 

(6) Record Keeping and Reporting Requirements. 

* * * * 

(E) The information gathered by the manufacturer to compile the reports required 

by these procedures must be retained for no less than one year beyond when 

engines within the engine class, on average, exceed the defined full useful life 

of the engines and must be made available to authorized personnel of ARB 

upon request. 

* * * *