OBD Readiness Testability Issues 

OBD Readiness Testability Issues 


Transportation and Regional Programs Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency 

EPA-420-B-11-022 

May 2011 
 

 

OBD ReadinessTestability Issues1 

Make Model 

Year Model Problem Action 

Acura 1997 2.5 TL 

Trouble 

communicating with 

some scan tools 

Attempt communication with a different scan tool. 

See OBD clearinghouse for more information. 

Audi and 

Volkswagen 1996-2002 

All models 

with non-OEM 

stereos 

If OEM stereo has 

been replaced with 

an aftermarket unit, 

the OBD system may 

not communicate 

with and may 

damage the scan tool 

Ensure scan tool has complete current/voltage 

override protection. For more information, see VW 

Technical service bulletin 02-03 dated June 10, 

2002. 

Chrysler 1996 built 

prior to 

11/21/95 

Cirrus, 

Sebring, 

Sebring 

Convertible, 

Concord, LHS 

All monitors reset to 

incomplete upon 

every ignition key-off. 

Recall campaign #678 applies to California certified 

vehicles in California. TSB #18-005-01 applies to all 

other vehicles with a lifetime warranty. 

Chrysler 2010 built 

prior to 

2/20/10 

300 with 3.5L 

engine and 5-

speed 

automatic 

transmission 

Evaporative Leak 

Detection Monitor 

may not set to ready 

TSB# 18-008-10 Revision A 

Dodge 1996 built 

prior to 

11/21/95 

Stratus, 

Intrepid, Neon, 

Avenger 

All monitors reset to 

incomplete upon 

every ignition key-off 

Recall campaign #678 applies to California certified 

vehicles in California. TSB #18-005-01 applies to all 

other vehicles with a lifetime warranty. 

Dodge 1996 Stealth All monitors reset to 

incomplete upon 

every ignition key-off 

These vehicles are not reflashable and should be 

tested without regard to monitor readiness 

Dodge 2003 Dakota, 

Durango and 

Ram Trucks 

with 4.7L 

engine and 

California or 

50 state 

certified. 

Catalyst monitor 

readiness status may 

indicate not 

supported 

TSB#18-032-10 with lifetime warranty 

Dodge 2003 Ram Truck 

with Cummins 

5.9L diesel 

engine and 

California 

certified 

MIL may illuminate 

erroneously. 

Comprehensive 

component monitor 

status may not set to 

ready 

Recall Campaign #K01 

Dodge 2004-5 Ram Truck 

with Cummins 

5.9L diesel 

engine and 

California 

certified 

Comprehensive 

component monitor 

status may not set to 

ready 

TSB#18-030-10 with lifetime warranty 

Dodge 2006-7 Ram Truck 

with Cummins 

5.9L diesel 

engine. 

Fuel system monitor 

and comprehensive 

component monitor 

status may not set to 

ready 

Recall campaign #K01 applies to California certified 

vehicles. TSB#18-017-10 with lifetime warranty 

applied to federal certified vehicles. 

1

 Formerly known as Appendix D, this table lists specific vehicle makes and models with OBD readiness issues along with resolutions for I/M 

programs to use at their discretion to overcome those issues. 

Page 1 of 5 Revised May 2011 
 

 

 

 

 

 

OBD ReadinessTestability Issues1 

Make Model 

Year Model Problem Action 

Dodge 2007 built 

prior to 

01/06/07 

Ram Chassis 

Cab with 

Cummins 6.7L 

diesel engine 

Trucks are not 

equipped with 

oxygen sensors but 

oxygen sensor and 

oxygen sensor heater 

monitors may report 

as not ready. 

Comprehensive 

component monitor 

status may not be set 

to ready 

Recall campaign #K01 applies to California certified 

vehicles. TSB#18-017-10 with lifetime warranty 

applied to federal certified vehicles. 

Dodge 2010 built 

prior to 

2/20/10 

Charger, 

Challenger 

with 3.5L 

engine and 5-

speed 

automatic 

transmission 

Evaporative leak 

detection monitor 

may not set to ready 

TSB# 18-008-10 Revision A 

Eagle 1996 built 

prior to 

11/21/95 

Vision, Nonturbo Talon All monitors reset to 

incomplete upon 

every ignition key-off 

TSB #18-005-01 applies with a lifetime warranty 

Eagle 1996 Summit, 

Summit 

Wagon 

All monitors reset to 

incomplete upon 

every ignition key-off 

These vehicles are not reflashable and should be 

tested without regard to monitor readiness. 

Eagle 1996-8 Talon with 

2.0L Turbo 

All monitors reset to 

incomplete upon 

every ignition key-off 

These vehicles are not reflashable and should be 

tested without regard to monitor readiness. 

Ford 2000-2002 All 

Evap monitors may 

be difficult to 

complete 

Follow recommended drive cycles. See OBD 

clearinghouse. Otherwise test as normal. 

Ford 2003 Focus Monitors may be 

difficult to complete 

Powertrain control module needs to be updated. 

See TSB 06-7-5. Otherwise test as normal. 

Hyundai 2002 Sonata 

Monitors are difficult 

to complete; perform 

drive cycle 2 times 

Follow drive cycle in TSB #02-36-030 applies. 

Otherwise test as normal. 

Hyundai 2003 Tiburon 

Will not communicate 

with generic OBD 

test equipment 

A manufacturer recall is in effect; recall campaign 

#057 and Hyundai TSB #03-01-003-01. Otherwise 

test as normal. 

Infiniti 1996 All models 

Catalyst and 

evaporative system 

monitors are difficult 

to complete 

Follow drive cycle in TSB #NTB98-018, February 

18, 1998. Otherwise test as normal. 

Jeep 2005-6 Wrangler Oxygen sensor 

heater readiness 

status bit remains 

incomplete. 

TSB #25-001-07 

Jeep 2010-11 

built before 

09/02/10 

Wrangler with 

3.8L engine 

Downstream oxygen 

sensor monitor may 

not set to ready 

TSB #18-027-10 

Maserati 2005+ All models 

VIN may not display 

properly on hand 

held scan tools 

See TSB# MTB 148A Writing 

Mitsubishi 1996-1998 All models Catalyst monitor is 

difficult to complete 

The OBD readiness criteria for this vehicle allow 

two monitors to be incomplete. Test as normal. 

Page 2 of 5 Revised May 2011 
 

 

 

 

 

 

 

 

OBD ReadinessTestability Issues1 

Make Model 

Year Model Problem Action 

Mitsubishi 1998-2001 

Montero, 

Montero Sport, 

Diamante, 

3000GT, 

Mirage, 

Galant, 

Expo/Expo 

LRV, and 

Eclipse 

models 

(except 2.0L 

non--turbo 

420A engine 

models) 

Some monitors are 

difficult to complete 

Follow recommended drive cycles in Mitsubishi 

service manual. Otherwise, test as normal. 

Nissan 1996-1997 All models 

Catalyst and 

evaporative system 

monitors are difficult 

to complete 

Follow recommended drive cycles. See Nissan TSB 

#NTB98-018, January 3, 2002. Otherwise, test as 

normal. 

Nissan 1999-2006 All models Monitors can be 

difficult to complete 

Follow owner’s manual drive cycle to achieve 

readiness. Otherwise, test as normal. 

Plymouth 1996 built 

prior to 

11/21/95 

Breeze, Neon All monitors reset to 

incomplete upon 

every ignition key-off 

Recall campaign #678 applies to California certified 

vehicles in California. TSB #18-005-01 applies to all 

other vehicles with a lifetime warranty. 

Saab 1996-1998 

900 

(B234i with 

Motronic 4.1) 

Monitors are difficult 

to complete 

Saab Service Instruction No. 248 describes the 

correct drive cycle for completion of the monitors. 

Otherwise, test as normal. 

Saab 1996-1998 All models 

Catalyst and 

evaporative system 

monitors are difficult 

to complete 

The OBD readiness criteria for this vehicle allow 

two monitors to be incomplete. Test as normal. 

Subaru 1996 All models Readiness cleared at 

key-off 

Scan vehicle for MIL illumination without regard to 

readiness. 

Suzuki 2001 Aerio Monitors can be 

difficult to complete 

Follow drive cycle. See OBD Clearinghouse or 

Suzuki service information. 

Suzuki 2004 Forenza Monitors can be 

difficult to complete 

Follow drive cycle. See OBD Clearinghouse or 

Suzuki service information. 

Toyota/Lexus 1996-2006 All models Monitors can be 

difficult to complete Follow drive cycles in Toyota service information. 

Toyota 1996-1997 Tercel, Paseo 

Evaporative system 

monitor will never 

complete or is 

unsupported 

The OBD readiness criteria for these model years 

allow two monitors to be incomplete. Test as 

normal. 

Volvo 1996-1998 

All models 

excluding the 

850 Turbo 

Catalyst and 

evaporative system 

monitors are difficult 

to complete 

Follow recommended drive cycles in Service 

Bulletin 2-23-0056. Otherwise test as normal. 

Volvo 1996 850 Turbo Vehicle clears 

readiness at key-off 

Scan for MIL illumination without regard to 

readiness status. See Volvo SB-2-23-0056. 

Volvo 2004-2006 S40, V50 

Air conditioning 

monitor mistakenly 

set to supported 

instead of 

unsupported 

Ignore A/C monitor status and otherwise test as 

normal. 

Volvo 2005-2007 XC90 

Air conditioning 

monitor mistakenly 

set to supported 

instead of 

unsupported 

Ignore A/C monitor status and otherwise test as 

normal. 

Page 3 of 5 Revised May 2011 
 

Flex Fuel Vehicle Testability Issues2 

Model 

Year Model Engine Engine Family and VIN Problem Action 

Chrysler 

1998 

Chrysler Caravan 

and Town and 

Country / Dodge 

Caravan / Plymouth 

Voyager 

3.3L V-6 

(E85) 

WCRXT03.32BP 

(VIN 8th digit: G) 

All monitors disabled for operation 

>E30 and ethanol fuel content 

learning. 

Desensitized system monitors: 

 fuel system rail check only for 

>E30; 

 fuel system rich for >E50; 

 fuel system lean and misfire for E0-

E10 and coolant temp >230 deg. F; 

 purge flow check. 

Test without 

regard to monitor 

readiness 

1999 

Chrysler Town and 

Country / Dodge 

Caravan / Plymouth 

Voyager 

3.3L V-6 

(E85) 

XCRXT03.32BP 

(VIN 8th digit: G) 

2000 

Chrysler Caravan, 

Voyager, and Town 

and Country / Dodge 

Caravan / Plymouth 

Voyager 

3.3L V-6 

(E85) 

YCRXT03.32BP 

(VIN 8th digit: G) 

Ford 

2002 Ford Ranger 

2-wheel drive 

3.0L V-6 

(E85) 

2FMXT03.02F6 

(50 State) 

(VIN 8th digit: V) 

Monitors Disabled for operation >E10 

blends: catalyst. 

Desensitized evaporative leak/purge 

check monitor to detect gross leak for 

operation >E75 blends (monitor fully 

compliant up to E75 blends). 

Test without 

regard to monitor 

readiness 

General Motors 

2000 

Chevrolet S-10/GMC 

Sonoma 

2-wheel drive 

2.2 L I-4 

(E85) 

YGMXT02.2121 

YGMXT02.2122 

(VIN 8th digit: 5) 

System monitors disabled for 

operation ≥E15 blends: O2 sensor 

heater, secondary air, catalyst. 

System monitors disabled for 

operation ≥E10 blends: evaporative 

leak check. 

Desensitized O2 sensor monitor 

implemented; only reports faults during 

operation ≤E15 blends. 

Test without 

regard to monitor 

readiness 

2001 

Chevrolet S-10/GMC 

Sonoma 

2-wheel drive 

2.2 L I-4 

(E85) 

1GMXT02.2122 

(VIN 8th digit: 5) 

System monitors disabled for 

operation ≥E15 blends: O2 sensor 

heater, secondary air, catalyst. 

System monitors disabled for 

operation ≥E10 blends: evaporative 

leak check. 

Desensitized O2 sensor monitor 

implemented; only reports faults during 

operation ≤E15 blends. 

Test without 

regard to monitor 

readiness 

This table identifies Flexible Fuel Vehicles (FFV) that have a U.S. EPA exception from performing some OBD functions while under operation with an 

alternative fuel. Although some OBD functionally may not be present, the OBD inspection shall be performed for the operative monitors. 

Page 4 of 5 Revised May 2011 

2 
Flex Fuel Vehicle Testability Issues2 

Model 

Year Model Engine Engine Family and VIN Problem Action 

2002 

Chevrolet S-10/GMC 

Sonoma 

2-wheel drive 

2.2 L I-4 

(E85) 

2GMXT02.2122 

(VIN 8th digit: 5) 

System monitors disabled for 

operation ≥E15 blends: O2 sensor 

heater, secondary air, catalyst. 

System monitors disabled for 

operation ≥E10 blends: evaporative 

leak check. 

Desensitized O2 sensor monitor 

implemented; only reports faults during 

operation ≤E15 blends. 

Isuzu 

2000 Hombre 

2-wheel drive 

2.2 L I-4 / 

(E85) 

YGMXT02.2121 

YGMXT02.2122 

(VIN 8th digit: 5) 

This model shares a platform with the 

Chevrolet S-10 and GMC Sonoma. 

For guidance on these models, 

please refer to General Motors 

section. 

Test without 

regard to monitor 

readiness 2001 Hombre 

2-wheel drive 

2.2 L I-4 / 

(E85) 

YGMXT02.2121 

YGMXT02.2122 

(VIN 8th digit: 5) 

Mazda 

2002 B3000 

2-wheel drive 

3.0 L V-6 

(E85) 

2FMXT03.02F6 

(VIN 8th digit: V) 

This model shares a platform with the 

Ford Ranger. 

For guidance on these models, 

please refer to Ford section. 

Test without 

regard to monitor 

readiness 2003 B3000 

2-wheel drive 

3.0 L V-6 

(E85) 

3FMXT03.02F6 

(VIN 8th digit: V) 

Page 5 of 5 Revised May 2011