I. Understanding OBD2 Vehicle Monitors
On-Board Diagnostics II (OBD2) systems are integral to modern vehicles, acting as the car’s self-diagnostic and reporting system. An Obd2 Vehicle Monitor is a crucial component of this system, responsible for overseeing specific emission control systems and components to ensure they are functioning correctly and minimizing pollution. This article provides a comprehensive overview of OBD2 vehicle monitors, their pass/fail criteria in smog checks, and guidance for resolving common issues.
What are OBD2 Monitors?
OBD2 monitors are essentially self-tests that a vehicle’s computer ( Powertrain Control Module or PCM) performs on emission control systems. These monitors run in the background during normal driving conditions, checking if components like the catalytic converter, oxygen sensors, and evaporative system are working within acceptable parameters. When a monitor runs and completes successfully, it sets a “ready” status. If a fault is detected, the monitor may set a Diagnostic Trouble Code (DTC) and illuminate the Malfunction Indicator Lamp (MIL), commonly known as the “Check Engine” light.
There are two main categories of OBD2 monitors:
-
Readiness Monitors (Non-Continuous Monitors): These monitors are designed to run and complete under specific driving conditions. They test systems that do not require constant monitoring. Examples include:
- Catalyst Monitor: Checks the efficiency of the catalytic converter.
- Oxygen Sensor Monitor: Tests the functionality of oxygen sensors.
- Evaporative System Monitor: Detects leaks in the fuel vapor recovery system.
- EGR System Monitor: Monitors the Exhaust Gas Recirculation system.
- Secondary Air System Monitor: Tests the secondary air injection system (if equipped).
- Heated Catalyst Monitor: Checks the performance of heated catalytic converters (if equipped).
- Oxygen Sensor Heater Monitor: Verifies the functionality of oxygen sensor heaters.
- Air Conditioning System Monitor: Monitors the A/C system operation (in some vehicles, may be incorrectly reported as supported).
- NMHC Catalyst Monitor: (Non-Methane Hydrocarbon Catalyst) – For some diesel vehicles.
- NOx/SCR Monitor: (Nitrogen Oxides/Selective Catalytic Reduction) – For some diesel vehicles.
- Particulate Filter Monitor: – For diesel particulate filters.
-
Continuous Monitors: These monitors run constantly whenever the engine is operating. They are always evaluating critical emission-related components. Examples include:
- Misfire Monitor: Detects engine misfires that can increase emissions.
- Fuel System Monitor: Checks the fuel delivery system for proper operation.
- Comprehensive Components Monitor: Monitors a wide range of sensors, actuators, and the PCM itself for malfunctions.
Why are OBD2 Monitors Important?
obd2 vehicle monitors play a vital role in:
- Emission Control: By continuously monitoring emission systems, they ensure vehicles meet emission standards and reduce air pollution.
- Vehicle Diagnostics: Monitors help identify potential problems early, even before they become major issues, allowing for timely repairs and preventing more significant damage.
- Smog Check Inspections: In many regions, OBD2 monitor status is a crucial part of vehicle emission testing (smog checks). Vehicles must have a certain number of monitors in a “ready” state to pass the OBD portion of the inspection.
II. OBD2 Monitor Pass/Fail Standards for Smog Checks
During a smog check inspection, the OBD2 system is tested to ensure it is functioning correctly. The pass/fail standards primarily revolve around readiness monitor status, the Malfunction Indicator Lamp (MIL), vehicle communication, Permanent Diagnostic Trouble Codes (PDTCs), and modified software.
Readiness Monitor Standards
Readiness monitors must be completed for a vehicle to pass the OBD test portion of a smog check. However, some incomplete monitors are permitted depending on the vehicle’s model year and fuel type. The allowances are designed to accommodate vehicles where certain monitors are difficult to complete under normal driving conditions.
| Model Year | Fuel Type | Number of Incomplete Monitors Allowed to Pass OBD Test¹ |
|---|---|---|
| 1996-1999 | Gas² | Any one³ |
| 2000 and newer | Gas² | Evaporative system³ |
| 1998-2006 | Diesel | Zero |
| 2007 and newer | Diesel | Particulate Filter and Non-Methane HydroCarbon (NMHC)⁴ |
¹ Implemented May 4, 2015.
² “Gas” includes gasoline, propane, natural gas (CNG, LNG, LPG).
³ The misfire, fuel, and comprehensive component continuous monitors are ignored during an OBD test on “gas” vehicles.
⁴ Implemented July 5, 2023.
It’s important to note that clearing DTCs or disconnecting the vehicle’s battery will reset readiness monitors to “not ready.” After such actions, the vehicle needs to be driven through specific drive cycles to allow the monitors to run and reset to “ready.” These drive cycles vary by manufacturer and model and are designed to create the conditions necessary for each monitor to execute its self-test.
Malfunction Indicator Lamp (MIL) Standards
The MIL, or “Check Engine” light, is a critical indicator of OBD system health. The following standards apply to the MIL during a smog check:
| Vehicle | Pass/Fail | Standard |
|---|---|---|
| All with OBDII | Pass | MIL illuminates when key on engine off (KOEO). |
| All with OBDII | Pass | MIL turns off when engine running (KOER). |
| All with OBDII | Fail | MIL does not illuminate when key on engine off (KOEO). |
| All with OBDII | Fail | MIL illuminates when engine running (KOER). |
The MIL should illuminate briefly when the ignition is turned to the “ON” position but the engine is not yet started (KOEO – Key On Engine Off). This confirms the MIL bulb is functional. Once the engine is running (KOER – Key On Engine Running), the MIL should turn off if no emission-related faults are present. If the MIL remains illuminated while the engine is running, it indicates a problem, and the vehicle will fail the OBD test. A failed MIL KOEO test also results in a failed OBD test, indicating a potential issue with the MIL circuit itself.
Communication Standards
Successful communication between the smog check equipment and the vehicle’s OBD2 system is essential. Communication failure can occur due to various reasons:
| Vehicle | BAR-97/OIS | Standard |
|---|---|---|
| All with OBDII | BAR-97 | Vehicle communicates with BAR-97. |
| All with OBDII | OIS | Vehicle communicates with OIS and transmits required data.¹ |
¹ Required data typically means data from OBD addresses: Mode $01 PID $00, Mode $01 PID $01. Mode $01 PID $00 returns what data is supported on the vehicle. Mode $01 PID $01 returns MIL status, diagnostic trouble codes (DTCs), and monitor status.
Reasons for communication failure can include:
- Damaged OBD Connector or Wiring: Physical damage to the OBD2 port or associated wiring can prevent communication.
- Aftermarket Stereo Systems: Improperly installed aftermarket stereos can sometimes interfere with OBD2 communication.
- Computer Response Issues: In some cases, the scan tool might receive a response from the transmission computer instead of the engine computer.
- Invalid Data: The vehicle’s computer may be sending invalid or corrupted data, hindering communication.
Permanent Diagnostic Trouble Code (PDTC) Standards
Permanent Diagnostic Trouble Codes (PDTCs) are a specific type of DTC that cannot be cleared using a scan tool or by disconnecting the battery. They are designed to ensure that emission faults are properly addressed and not simply erased to pass an inspection.
| Model Year | BAR-97/OIS | Standard |
|---|---|---|
| 1996-1999 | BAR-97 | Not applicable. |
| 2000-2009 | OIS | Not applicable. |
| 2010 and newer ¹ | OIS | Vehicles fail when a PDTC is present. ²,³,⁴,⁵ |
¹ Some 2010 vehicles do not support PDTC. Those without support for PDTC will not be subject to the PDTC check.
² A vehicle with a PDTC stored will fail the PDTC check regardless of whether the MIL is commanded ON or OFF.
³ PDTC presence will be ignored if the vehicle has completed at least 15 warm-up cycles and been driven at least 200 miles since its OBD information was last cleared (as determined by Mode $01 PID $30 and $31).
⁴ BAR is aware of some vehicles that have trouble properly clearing certain PDTCs. BAR is working with the California Air Resources Board (CARB) to ensure that known problematic vehicles are addressed by vehicle manufacturers. Until then, these codes will be ignored by BAR-OIS. For more information, see Permanent Diagnostic Trouble Code Vehicles of Interest.
⁵ Vehicle manufacturers have issued extended warranties, recalls and repair campaigns for some vehicles that have trouble properly clearing PDTCs. These vehicles are listed under Permanent Diagnostic Trouble Code Vehicles of Interest. When one of these vehicles fails for the PDTC, please refer the motorist to the dealer for covered repairs.
A vehicle will fail the smog check if PDTCs are present, even if the MIL is not illuminated. PDTCs are only cleared automatically by the OBD2 system itself after it verifies that the underlying issue has been resolved over multiple drive cycles. However, the presence of PDTCs is ignored in specific situations, such as when the vehicle has completed a significant number of warm-up cycles and miles since the last code clearing, allowing for cases where a fault might have been intermittent and self-corrected. Additionally, certain vehicles known to have issues with PDTC clearing are exempted by BAR-OIS.
Modified Software Standards
To prevent tampering with emission control systems, smog checks also include a check for modified software in the vehicle’s PCM.
Vehicles with software that is not OEM-approved or CARB-approved (California Air Resources Board) will fail the smog check. This measure is in place to ensure that the vehicle’s emission control system is operating as originally designed and certified. If modified software is detected, the vehicle must be restored to an approved software configuration before it can pass a smog check. Consumers who dispute these results can contact the Smog Check Referee for further review.
III. Troubleshooting OBD2 Monitor Issues: Vehicles of Interest
Certain vehicle makes and models are known to exhibit specific issues related to obd2 vehicle monitor operation and smog check testing. These issues can range from communication problems to difficulties in completing readiness monitors or problems with Permanent Diagnostic Trouble Codes.
OIS Vehicles of Interest
The following gasoline, flex-fuel, and diesel vehicles (model year 2000 and newer for gasoline/flex-fuel, and 1998 and newer for diesel) have known issues that may affect the OBD test portion of an OIS inspection. These issues are often accommodated by the OIS system programming, or they may require vehicle repair.
| Make | Year | Model Engine (L); Fuel Type | Issue | Cause and Possible Remedy | Instruction to Inspector |
|---|---|---|---|---|---|
| Audi | 2000-2004 | A4 & A6 | Fail for no OBD communication. No response or Only Transmission Control Module responds to DADs requests. ABS and/or brake lamp illuminated in instrument panel cluster. | Broken ground bond wire in ABS module causes diagnostic communication issues with the ABS module, ECM, and TCM. Diagnose and repair per Audi TSB #A45-15-10. | Likely broken vehicle. Repair and retest. |
| BMW | 6/1/99 – 7/31/00 | 323i Sedan | May not pass inspection due to oxygen sensors readiness monitor not set/not fitted/not supported. | DME Software error. Reprogram DME with the updated software. | Check the DME “programmed control unit” number listed in TSB #SI B12 16 16 and follow TSB instructions. |
| BMW | 9/3/99 – 7/31/00 | 323iT Touring | May not pass inspection due to oxygen sensors readiness monitor not set/not fitted/not supported. | DME Software error. Reprogram DME with the updated software. | Check the DME “programmed control unit” number listed in TSB #SI B12 16 16 and follow TSB instructions. |
| BMW | 6/1/99 – 7/29/00 | 323Ci Coupe | May not pass inspection due to oxygen sensors readiness monitor not set/not fitted/not supported. | DME Software error. Reprogram DME with the updated software. | Check the DME “programmed control unit” number listed in TSB #SI B12 16 16 and follow TSB instructions. |
| BMW | 6/23/99 – 7/29/00 | 323 Cic Convertible | May not pass inspection due to oxygen sensors readiness monitor not set/not fitted/not supported. | DME Software error. Reprogram DME with the updated software. | Check the DME “programmed control unit” number listed in TSB #SI B12 16 16 and follow TSB instructions. |
| BMW | 2000 | M52 (TU) engine | May not pass inspection due to oxygen sensors readiness monitor not set/not fitted/not supported. | DME Software error. Reprogram DME with the updated software. | Check the DME “programmed control unit” number listed in TSB #SI B12 16 16 and follow TSB instructions. |
| BMW | 2000 | Fail for readiness. Vehicle may not set oxygen sensor readiness monitor. | Software error in ECM. Reflash ECM per Recall #00E-A01. See BMW bulletin #SI B 12 15 99, dated November 2000. | Vehicle requires reflash. Reflash ECM per recall so oxygen sensor monitor will set. | |
| BMW | built 3/98 – 7/99 | 323i, 323iA, 328i, 328iA | Fail for readiness. Vehicle may not set oxygen sensor readiness monitor. | Software error in ECM. Reflash ECM per Recall #00E-A01. See BMW bulletin #SI B 12 15 99, dated November 2000. | Vehicle requires reflash. Reflash ECM per recall so oxygen sensor monitor will set. |
| BMW | built 2/99 – 7/99 | 328iC, 328iCA, 323iC, 323iCA, 528i, 528iA, 528iT, 528iAT | Fail for readiness. Vehicle may not set oxygen sensor readiness monitor. | Software error in ECM. Reflash ECM per Recall #00E-A01. See BMW bulletin #SI B 12 15 99, dated November 2000. | Vehicle requires reflash. Reflash ECM per recall so oxygen sensor monitor will set. |
| BMW | built 9/98 – 7/99 | Z3 roadster 2.3 | Fail for readiness. Vehicle may not set oxygen sensor readiness monitor. | Software error in ECM. Reflash ECM per Recall #00E-A01. See BMW bulletin #SI B 12 15 99, dated November 2000. | Vehicle requires reflash. Reflash ECM per recall so oxygen sensor monitor will set. |
| BMW | built 4/99 – 7/99 | Z3 roadster coupe/ roadster 2.8 | Fail for readiness. Vehicle may not set oxygen sensor readiness monitor. | Software error in ECM. Reflash ECM per Recall #00E-A01. See BMW bulletin #SI B 12 15 99, dated November 2000. | Vehicle requires reflash. Reflash ECM per recall so oxygen sensor monitor will set. |
| BMW | 2001-2003 | Z3 M Roadster/coupe with S54 engine | Fail for no communication when ignition switched off/on. OBD communication always possible with BMW DIS or GT1 tester. | Voluntary Emissions Recall Campaign to reprogram the engine control units (DME) on all affected vehicles. Bulletin #SI B12 11 06 dated October 2007. | Follow OIS prompts. Connect/disconnect DAD when key off. |
| BMW | 2000-2003 | Z8 & M5 with S62 engine | Fail for no communication when ignition switched off/on. OBD communication always possible with BMW DIS or GT1 tester. | Voluntary Emissions Recall Campaign to reprogram the engine control units (DME) on all affected vehicles. Bulletin #SI B12 11 06 dated October 2007. | Follow OIS prompts. Connect/disconnect DAD when key off. |
| BMW | From series intro. up to 8/27/2004 | M3 with S54 engine | Fail for no communication when ignition switched off/on. OBD communication always possible with BMW DIS or GT1 tester. | Voluntary Emissions Recall Campaign to reprogram the engine control units (DME) on all affected vehicles. Bulletin #SI B12 11 06 dated October 2007. | Follow OIS prompts. Connect/disconnect DAD when key off. |
| BMW | 2003 | M3 | Failure to set EGR monitor. | Check thermostat | Likely broken vehicle. Repair and retest. |
| BMW | 2007 | 328i | Engine dies during OBD Test, won’t restart. | Separate the vehicle and key. Wait 20+ minutes. Attempt to restart. | Test normally. BAR-OIS will not request Cal ID or CVN. Possible keyless ignition related issue. The vehicle will recover by just letting it sit for 20+ minutes with the wireless key fob out of range of the vehicle. |
| Chevrolet | 1998-2005 | DIESEL C/K2500 & C/K3500 (including Silverado and Suburban), G30, G3500 (including Sport Van, Express Cut-Away & Cargo), P30 | Federal diesel vehicle over 8,500 GVWR is not OBD-II certified. | Federal diesel vehicles over 8,500 GVWR were not built to comply with OBD-II or Fed OBD standards. | Test normally. BAR-OIS will ignore incomplete continuous monitors. If the vehicle fails to communicate, use the result of the bulb check for the overall result of the OBD Test if the analyzer offers this option. |
| Chevrolet | 1999-2005 | 3500 W35042 (box truck) [GVWR 10,001 – 14,000] (diesel) [Federal certified] | Vehicle is not equipped with OBD II. | OBD not installed in federals during these years. | OIS programmed to skip the OBD functional test. |
| Chevrolet | 2000-2002 | S-10 (2WD), 2.2L I-4 (E85) | Monitors won’t set on certain flex fuel models, VINs listed below. YGMXT02.2121 YGMXT02.2122 1GMXT02.2122 2GMXT02.2122 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 Senor monitor implemented; only reports faults during operation E15 blends. | OIS ignores all 11 readiness monitors. |
| Chevrolet | 2000-2005 | Suburban, Silverado, Express, Avalanche (gasoline) [Federal certified] | Message appears during OIS OBD II test stating, “Unable to confirm this Vehicle’s OBD II requirements. Does this vehicle have OBD II?” | Federally certified vehicle may not be certified to OBD II standards. | Check under-hood emission label to determine OBD certification status. Enter correct result into OIS and follow OIS prompts. OIS may state a BAR-97 test is required on vehicles without OBDII. |
| Chevrolet | 2001 | Silverado / Tahoe C/K 1500 | Failure to set secondary air system monitor. | Possible air injection problem (check valve(s), vacuum line, pump, air passages). | Diagnose. Repair and retest. |
| Chevrolet | 2002 | Silverado C/K 2500HD (diesel) | Failure to set EGR monitor. | Difficult drive cycle. | OIS reprogrammed 10/13/2016 to allow monitor to be incomplete. |
| Chevrolet | 2001-2002 | Cavalier CNG First VIN digit “3” (built in Mexico) | Failure to set CAT monitor. | Vehicle design anomaly. | OIS reprogrammed 02/11/2015 to allow any one monitor to be incomplete. |
| Chevrolet | 2019 | Express 2.8L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. A Particulate Matter sensor fault may not set DTC or illuminate MIL. | The Engine Control Module (ECM) may not properly handle diagnostic information for the exhaust Particulate Matter (PM) sensor. Dealers are to reprogram the ECM per Emission Recall N232408230. | Vehicle requires reflash. Perform recall then retest. |
| Chrysler | 1999-2000 | Town & Country with 3.0L engine built after 12/1/1998 | EGR Monitor will not complete at high altitude. | Reflash available. Confirm all systems functioning. Erase and reprogram PCM per TSB 18-03-00. | Vehicle requires reflash. Repair per TSB, run monitors then retest. |
| Chrysler | 2000 | Town and Country 3.3L V-6 (E-85) | Readiness monitors will not set on certain flex fuel models, VINs listed below. WCRXT03.32BP (VIN 8th digit: G) | All monitors disabled for operation >E30 and ethanol fuel content learning. | OIS ignores all 11 readiness monitors. |
| Chrysler | 2003 | PT Cruiser 2.4 liter DOHC 16v turbocharged (sales code EDV) with 5- spd manual G288 trans (sales code DDD) | Failure to set catalyst monitor. | PCM software error. Dealer must reprogram PCM. Emissions warranty extended to lifetime for this issue. Diagnose and repair per TSB #18-112-16. Possible repair payment reimbursement, see warranty D-16-26. | Vehicle requires reflash. Repair per TSB and retest. |
| Chrysler | 2010 built prior to 2/20/2010 | 300, Charger, Challenger 3.5L (5 speed automatic transmission) | Fail for monitor readiness, Or MIL illumination: P0456, P0452, P1115. | Reflash available. See Chrysler TSB #18-008-10 | Vehicle requires reflash. Repair per TSB and retest. |
| Dodge | 1998-2002 | Ram Truck 5.9L (Cummins diesel) [California certified] | Some continuous monitors will not complete. | Vehicle design anomaly. | Test normally. BAR-OIS allows one incomplete continuous monitor. |
| Dodge | 1998-2006 | Ram 2500, Ram 3500 (diesel) [Federal certified] | Federal diesel vehicle over 8,500 GVWR is not OBD-II certified. | Federal diesel vehicles over 8,500 GVWR were not built to comply with OBD-II or Fed OBD standards. | Test normally. BAR-OIS will ignore incomplete continuous monitors. If the vehicle fails to communicate, use the result of the bulb check for the overall result of the OBD Test if the analyzer offers this option. |
| Dodge | 1999-2000 | Caravan with 3.0L engine built after 12/1/1998 | EGR Monitor will not complete at high altitude. | Reflash available. Confirm all systems functioning. Erase and reprogram PCM per TSB 18-03-00. | Vehicle requires reflash. Repair per TSB, run monitors then retest. |
| Dodge | 2003 | Dakota, Durango and Ram Trucks with 4.7L engine [California or 50 state certified] | Catalyst monitor readiness status shows as not supported. | Broken vehicle, repair per TSB #18-032-10 with lifetime warranty. | Test normally. OIS ignores unsupported monitors. |
| Dodge | 2003 | Ram Truck 5.9L (Cummins diesel) [California certified] | MIL light is commanded on, but check engine light is not illuminated and no DTCs are stored. | Vehicle design anomaly Recall campaign #K01 for ECM reflash applies to California certified vehicles only. | Test normally. OIS ignores MIL Command if no DTCs are present on this vehicle Advise motorist of Recall Campaign #K01 if the vehicle is California certified. |
| Dodge | 2003-2004 | 25004X2 and Sprinter 35004X2 (diesel) [2003 Federal certified] [2004 Federal certified] | Federal diesel vehicle over 8,500 GVWR is not OBD-II certified. | Federal diesel vehicles over 8,500 GVWR were not built to comply with OBD-II or Fed OBD standards. | Test normally. BAR-OIS will ignore incomplete continuous monitors. If the vehicle fails to communicate, use the result of the bulb check for the overall result of the OBD Test if the analyzer offers this option. |
| Dodge | 2004-2005 built after 12/7/2003 | Ram Truck 5.9L (Cummins diesel) [California certified] | Comprehensive component monitor will not complete. | Vehicle design anomaly Re-flash available per TSB #18-030-10 with lifetime warranty per TSB #18-003-11. | Test normally. OIS allows one incomplete readiness monitor. Advise motorist of fix with lifetime warranty per TSB #18-003-11. |
| Dodge | 2004-2006 | 2500 3500 Sprinter (diesel) | EGR/VVT monitor will not complete. | ECU software error. | Test normally. OIS will ignore EGR/VVT monitor. |
| Dodge | 2005 | Ram Truck 5.9L (Cummins diesel) [Federal certified] | Misfire and Comprehensive Components monitors will not complete. | Vehicle design anomaly. | Test normally. OIS ignores misfire and comprehensive component monitor readiness. |
| Dodge | 2006-2007 | Ram Truck 5.9L, 6.7L (Cummins diesel) [California certified] | Fuel System and Comprehensive Components monitors will not complete. | Recall campaign #K01 for ECM reflash applies to California certified vehicles only. | Test normally. OIS ignores fuel and comprehensive component monitor readiness. Advise motorist of Recall Campaign #K01 if the vehicle is California certified. |
| Dodge | 2006-2007 | Ram Truck with 5.9L (ETC or ETH) built after 1/1/06, [Federal Certified], Cab Chassis with 6.7L (ETJ) built before 1/11/07 (Cummins diesel) [Federal certified] | Fuel System and Comprehensive Components monitors will not complete. | TSB #18-017-10 for ECM reflash applies to Federal certified vehicles only. | Test normally. OIS ignores fuel and comprehensive component monitor readiness. Advise motorist of TSB #18-017-10 if the vehicle is Federal certified. |
| Dodge | 2010 built before 2/20/10 | 300, Charger, Challenger 3.5L (5 speed automatic transmission) | Evaporative monitor will not set. | Evaporative leak detection monitor may not set to ready. | Test normally. Inform consumer of TSB #18-008-10 Revision A. |
| Dodge/Ram | 2010-2015 | 2500 & 3500 6.7L (diesel) [California certified] | NOx after-treatment monitor will not complete. | Vehicle design anomaly. | Test normally. BAR-OIS temporarily allows NOx after-treatment monitor to be incomplete until vehicle manufacturer remedy is available. |
| Dodge/Ram | 2014 | ProMaster 2500 & 3500 High 3.0L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. | Vehicle design anomaly. Dealers are to perform Recall V97 and ZC0. | Vehicle requires reflash. Perform recall then retest. |
| Dodge/Ram | 2015 | ProMaster 1500, 2500, & 3500 High & Standard 3.0L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. | Vehicle design anomaly. Dealers are to perform Recall V97 and ZC0. | Vehicle requires reflash. Perform recall then retest. |
| Dodge/Ram | 2016 | ProMaster 2500 & 3500 High 3.0L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. | Vehicle design anomaly. Dealers are to perform Recall V97. | Vehicle requires reflash. Perform recall then retest. |
| Ford | 1998-2003 | Truck 7.3L (diesel) | Engine could shut off when requesting Mode $09 data with aftermarket scan tool. | Vehicle design anomaly. | Test normally. OIS programmed to skip Mode $09 data request on these vehicles. |
| Ford | 1998-2004 | F250, F350, E350, E450, E Super Duty, Econo Commercial S- Duty, Econo RV S- Duty (diesel) [Federal certified] | Federal diesel vehicle over 8,500 GVWR is not OBD-II certified. | Federal diesel vehicles over 8,500 GVWR were not built to comply with OBD-II or Fed OBD standards. | Test normally. BAR-OIS will ignore incomplete continuous monitors. If the vehicle fails to communicate, use the result of the bulb check for the overall result of the OBD Test if the analyzer offers this option. |
| Ford | 2000-2004 | F250, F350, E350, Excursion (gasoline) [Federal certified] | Message appears during OBD II test stating, “Unable to confirm this Vehicle’s OBD II requirements. Does this vehicle have OBD II?” | Federally certified vehicle may not be certified to OBD II standards. | Check under-hood emission label to determine OBD certification status. Enter correct type into OIS and follow OIS prompts. OIS may state a BAR-97 test is required on vehicles without OBDII. |
| Ford | 2003 | Focus | Fail for readiness. | Monitors may be difficult to complete. | Broken Vehicle. Reflash PCM per TSB #06-7-5. Then test normally. |
| Ford | 2004 | E350 Super duty 5.4 (gas) | Failure to set CAT monitor. | Vehicle design anomaly Recall #15E06 dated 1/13/2016 may apply. Reflash ECM so CAT monitor will set. | Vehicle requires reflash. Repair per recall and retest. |
| Ford | 2011 | Edge, Explorer 3.5L & 3.7L | Vehicle fails for readiness. Some vehicles do not set readiness monitors. | Some vehicles clear the OBD-II diagnostic data on every engine start and/or incorrectly report the VIN. Reprogram or update vehicle’s calibration. Perform monitor drive cycle. | Please consult Ford Emission Recall #13E04 for applicability. Owner must ensure recall is performed if required and all monitor drive cycles are completed prior to Smog Check testing. |
| Ford | 2013-2016 | F series, Super Duty 6.7L (diesel) | Exhaust Gas Sensor monitor will not complete. | After DOC or DPF replacement on vehicles , EGS monitor will not run until degreening strategy completes (up to 6,000 to 10,000 miles). | Test normally. OIS will ignore incomplete EGS monitor on certain VINs provided by Ford where the DOC or DPF were replaced after January 1, 2022. Other vehicles are currently under investigation. Expires 10/8/2025. |
| Ford | 2015-2019 | Transit 3.2L (diesel) | Exhaust Gas Sensor monitor will not complete. | After DOC or DPF replacement, EGS monitor will not run until degreening strategy completes (up to 6,000 to 10,000 miles). | Test normally. OIS will ignore incomplete EGS monitor on certain VINs provided by Ford where the DOC or DPF were replaced after January 1, 2022. Other vehicles are currently under investigation. Expires 10/8/2025. |
| Ford | 2020-2022 | Escape; all engines; Gasoline and hybrid | Might not communicate with BAR-OIS. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. Similar messaging will be displayed on the OIS during the inspection, and printed on the VIR for consumers. |
| Ford | 2021-2022 | Bronco Sport; all engines; Gasoline (not hybrid) | Might not communicate with BAR-OIS. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. Similar messaging will be displayed on the OIS during the inspection, and printed on the VIR for consumers. |
| Ford | 2021-2023 | E350, E450; all engines; Gasoline (not hybrid) | Might not communicate with BAR-OIS. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. Similar messaging will be displayed on the OIS during the inspection, and printed on the VIR for consumers. |
| Ford | 2025 and newer | Explorer (2.3L) AWD, RWD. Test Group SFMXT02.34K2. | Fail for no OBD communication. | Vehicle has OBDonUDS. DAD 1.0 units will not communicate with OBDonUDS vehicles. | Cal-VIS software programmed to skip the OBD test until DAD 2.0 units are BAR certified. |
| Freightliner | 1998-2004 | M Line Walk In Van [GVWR 6,001-14,000] (diesel) [Federal certified] | Vehicle is not equipped with OBD II. | OBD not required in federally certified vehicles in this GVWR range during these years. | OIS programmed to skip the OBD functional test. |
| Freightliner | 2004-2006 | Sprinter (diesel) | EGR/VVT monitor will not complete. | ECU software error. | Test normally. OIS will ignore EGR/VVT monitor. |
| GM | 2000 – 2008 | Various models, and Silverado 1500 | OIS prompts for no vehicle voltage. | No power on vehicle’s OBDII connector (DLC pin 16). Possible blown fuse. | Use auxiliary DAD cables / power supply per DAD manufacturer’s instructions. |
| GM | 2015-2017 | All gasoline powered | Fail for readiness. | Post catalyst oxygen sensor monitor will not run until after 1,000 mile catalyst break in. See Bulletin #15-NA-010. | Inspect vehicle after 1,000 miles or send to Referee. |
| GMC | 1998-2005 | DIESEL C/K2500 & C/K 3500 (including Suburban and Sierra), Savana G3500, Workhorse P30 Forward Cntl | Federal diesel vehicle over 8,500 GVWR is not OBD-II certified. | Federal diesel vehicles over 8,500 GVWR were not built to comply with OBD-II or Fed OBD standards. | Test normally. BAR-OIS will ignore incomplete continuous monitors. If the vehicle fails to communicate, use the result of the bulb check for the overall result of the OBD Test if the analyzer offers this option. |
| GMC | 1999-2005 | W3500 W35042 (box truck) [GVWR 10,001 – 14,000] (diesel) [Federal certified] | Vehicle is not equipped with OBD II. | OBD not required in federally certified vehicles in this GVWR range during these years. | OIS programmed to skip the OBD functional test. |
| GMC | 2000-2002 | Sonoma (2WD), 2.2L I-4 (E85) | Monitors won’t set on certain flex fuel models, VINs listed below. YGMXT02.2121 YGMXT02.2122 1GMXT02.2122 2GMXT02.2122 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 Senor monitor implemented; only reports faults during operation E15 blends. | All 11 readiness monitors ignored in OIS. |
| GMC | 2000-2005 | Sierra, Yukon, Savana (gasoline) [Federal certified] | Message appears during OIS OBD II test stating, “Unable to confirm this Vehicle’s OBD II requirements. Does this vehicle have OBD II?” | Federally certified vehicle may not be certified to OBD II standards. | Check under-hood emission label to determine OBD certification status. Enter correct type into OIS and follow OIS prompts. OIS may state a BAR-97 test is required on vehicles without OBDII. |
| GMC | 2002 | Sierra C/K 2500HD (diesel) | Failure to set EGR monitor. | Difficult drive cycle. | OIS reprogrammed 10/13/2016 to allow monitor to be incomplete. |
| GMC | 2019 | Savana 2.8L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. A Particulate Matter sensor fault may not set DTC or illuminate MIL. | The Engine Control Module (ECM) may not properly handle diagnostic information for the exhaust Particulate Matter (PM) sensor. Dealers are to reprogram the ECM per Emission Recall N232408230. | Vehicle requires reflash. Perform recall then retest. |
| GMC | 2022 | Sierra K2500 SLT 6.6L (diesel) [California certified] | Exhaust Gas Sensor monitor will not complete. | Vehicle design anomaly. | Test normally. BAR-OIS temporarily allows Exhaust Gas Sensor monitor to be incomplete until vehicle manufacturer remedy is available. |
| Hyundai | 2002 | Sonata | Fail for readiness. | Monitors are difficult to complete; perform drive cycle two times. | Run drive cycle. See TSB #02-36-030. |
| Hyundai | 2003 | Tiburon | Will not communicate with generic OBD test equipment. | Pin 5 not grounded. Ground pin 5 by jumping to pin 4 in DLC per TSB. | Test normally on OIS. If using generic OBD test equipment, perform recall campaign #057 and Hyundai TSB #03-01-003-01. |
| Infiniti | 2000 -2001 | I30 | Failure to set catalyst monitor. | Only OEM scan tool shows OBD catalyst code. | Test catalyst and replace if defective. |
| Infiniti | 2000 -2001 | I30 | Fail for readiness. | Vehicle has difficulty completing all monitors during normal driving. | Run drive cycle. |
| Isuzu | 1998-2005 | NPR [GVWR 10,001- – 14,000] (diesel) [Federal certified] | Vehicle is not equipped with OBD II. | OBD not required in federally certified vehicles in this GVWR range during these years. | OIS programmed to skip the OBD functional test. |
| Isuzu | 2000-2002 | Hombre (2WD) 2.2L I-4 (E85) | Monitors wont set on certain flex fuel models, VINs listed below. YGMXT02.2121 YGMXT02.2122 1GMXT02.2122 2GMXT02.2122 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. | OIS ignores all 11 readiness monitors. |
| Jaguar | 2017 | Jaguar XE, XF, & F-Pace 2.0L (diesel) [California certified] Test Group HJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall H444. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Jaguar dealership for a software update. |
| Jaguar | 2018 | Jaguar XE, XF, F-Pace & Rover Velar 2.0L (diesel) [California certified] Test group JJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall H444. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Jaguar dealership for a software update. |
| Jaguar | 2019 | Jaguar XE, XF, & F-Pace 2.0L (diesel) [California certified] Test group KJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall H444. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Jaguar dealership for a software update. |
| Jeep | 2005-2006 | Wrangler | O2 sensor, O2 heater, and catalyst readiness monitors may indicate not ready. | Vehicle design anomaly. TSB #25-005-13 Rev. A contains wiring modification to make vehicle ready. | OIS allows incomplete O2 heater monitor. |
| Jeep | 2010-2011 | Wrangler 3.8L | Failure to set Oxygen sensor monitor. PCM not running monitor frequently enough. | Recall L34 (m/t) through 9/10/2010. Recall L35 (a/t) through 3/26/2011, and/or OEM drive cycle not working. | Reflash PCM per TSB 18-027-10. May need to run special drive cycle to set O2 monitor. [Coast from 70 to 30mph three times then pullover and restart engine.] |
| Kia | 2009 | Borrego LX/EX 3.8L | Fail for readiness. Vehicle may not set EGR monitor. | Vehicle has difficulty completing EGR monitor. Difficult to run drive cycle. | OIS reprogrammed 12/7/2017 to allow EGR/VVT monitor to be incomplete. |
| Land Rover | 2017 | Discovery, Range Rover, Range Rover Sport 3.0L (diesel)[California certified] Test group HJLXT03.0GTR | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall N808. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Land Rover dealership for a software update. |
| Land Rover | 2018 | Velar 2.0L (diesel) [California certified] Test group JJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall N808. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Land Rover dealership for a software update. |
| Land Rover | 2019 | Velar 2.0L (diesel) [California certified] Test group KJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall N808. | Test normally. If the vehicle you are inspecting fails the OBD test for incomplete NOx aftertreatment monitor, direct the vehicle to a Land Rover dealership for a software update. |
| Lexus | 2007 | RX400 Hybrid | Fail for oxygen sensor (air/fuel) monitor readiness. Air conditioning readiness monitor mistakenly set to supported instead of unsupported. | Air Fuel monitor issue. Perform software update to vehicle at no charge per Lexus campaign FLD with TSB #L-SB-0027-15. | If fails for incomplete oxygen sensor monitor, advise motorist recall may be required. Recall status: use https://www.toyota.com/recall. |
| Lincoln | 2011 | MKX 3.5L & 3.7L | Vehicle fails for readiness. Some vehicles do not set readiness monitors. | Some vehicles clear the OBD-II diagnostic data on every engine start and/or incorrectly report the VIN. Reprogram or update vehicle’s calibration. Perform monitor drive cycle. | Please consult Ford Emission Recall #13E04 for applicability. Owner must ensure recall is performed if required and all monitor drive cycles are completed prior to Smog Check testing. |
| Lincoln | 2020-2022 | Corsair; all engines; Gasoline and hybrid | Might not communicate with BAR-OIS. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. Similar messaging will be displayed on the OIS during the inspection, and printed on the VIR for consumers. |
| Mazda | 2000 | MPV | Failure to set Catalyst monitor. | May need catalyst and/or oxygen sensor. Diagnose and repair. | Likely broken vehicle. Repair and retest. |
| Mazda | 2002-2003 | B3000 (2WD) 3.0L V-6 (E-85) | Readiness monitors will not set on certain flex fuel models. | 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). | OIS ignores all 11 readiness monitors. |
| Mazda | 2003-2004 | Mazda 6 | Some vehicles may have a false MIL illumination during inspection with multiple U-code DTCs during OBDII test. The following OBD Codes may be set. (U1900-ABS, U2516-ABS, U1900-FF- IC, U2516-FF-IC, U0073-FF- PCM, U0073-FF-TCM, U0100-FF-TCM). | PCM sensitive to OBD tool connect or disconnect to DLC with ignition in the “On” position, or when the engine is running. See Mazda Service Bulletin #01-002/05 Dated 01/13/2005. Erase trouble codes, disconnect tool when ignition switch off. | Reset monitors. Connect/disconnect DAD to vehicle only when key off. |
| Mazda | 2005 | Mazda 6 (with 2.3 only) | Some vehicles may have a false MIL illumination during inspection with multiple U-code DTCs during OBDII test. The following OBD Codes may be set. (U1900-ABS, U2516-ABS, U1900-FF- IC, U2516-FF-IC, U0073-FF- PCM, U0073-FF-TCM, U0100-FF-TCM). | PCM sensitive to OBD tool connect or disconnect to DLC with ignition in the “On” position, or when the engine is running. See Mazda Service Bulletin #01-002/05 Dated 01/13/2005. Erase trouble codes, disconnect tool when ignition switch off. | Reset monitors. Connect/disconnect DAD to vehicle only when key off. |
| Mazda | 2003-2005 | Mazda 6 – 2.3 engine non PZEV (built May 20, 2002 – July 2, 2005) Mazda 6 – 3.0 engine (built May 16, 2002 – August 23, 2004) | Some vehicles may have a false MIL illumination during inspection. This will cause the vehicle to fail the test, although the vehicle itself has no problem. | PCM sensitive to OBD tool connect or disconnect to DLC with ignition in the “On” position, or when the engine is running. See TSB #01-024/05. If vehicle within VIN range reprogram PCM and TCM. Or Earlier Emission Recall TSB #1303F to Reprogram PCM applicable to certain VINs. | Follow OIS prompts. Connect/disconnect DAD when key off. |
| Mitsubishi Fuso | 1998-2004 | FE639/FG639 [GVWR 10,001 –14,000] (diesel) [Federal certified] | Vehicle is not equipped with OBDII. | OBD not required in federally certified vehicles in this GVWR range during these years. | OIS programmed to skip the OBD functional test. |
| Mitsubishi | 2000-2001 | Montero, Montero Sport, Diamante, 3000GT Mirage, Galant, Expo/Expo LRV, and Eclipse models (except 2.0L non—turbo 420A engine models). | Fail for monitor readiness. | Some monitors are difficult to complete. | Follow recommended drive cycles. See Mitsubishi service manual. |
| Nissan | 1999-2007 | UD1200, [GVWR 10,001-14,000] (Diesel) [Federal certified] | Vehicle is not equipped with OBDII. | OBD not required in federally certified vehicles in this GVWR range during these years. | OIS programmed 2/26/2016 to skip the OBD functional test. |
| Nissan | 2000-2001 | Maxima | Failure to set catalyst monitor. | Only OEM scan tool shows OBD catalyst code. | Test catalyst and replace if defective. |
| Nissan | 2000-2006 | All models | Fail for monitor readiness. | Incomplete monitors during normal driving. Follow drive cycle for that specific year, make, model, engine, certification, transmission. Run entire drive pattern even if only one monitor unset. | Follow drive cycle. See owner’s manual. |
| Plymouth | 1999-2000 | Voyager with 3.0L engine built after 12/1/1998 | EGR Monitor will not complete at high altitude. | Reflash available. Confirm all systems functioning. Erase and reprogram PCM per TSB 18-03-00. | Vehicle requires reflash. Repair per TSB, run monitors then retest. |
| Plymouth | 2000 | Voyager 3.3L V-6 (E-85) | Readiness monitors will not set on certain flex fuel models, VINs listed below. WCRXT03.32BP (VIN 8th digit: G). | All monitors disabled for operation >E30 and ethanol fuel content learning. | OIS ignores all 11 readiness monitors. |
| Suzuki | 2001 | Aerio | Fail for monitor readiness. | Monitors can be difficult to complete. | Follow drive cycle. See OBD Clearinghouse or Suzuki service information. |
| Suzuki | 2004 | Forenza | Fail for monitor readiness. | Monitors can be difficult to complete. | Follow drive cycle. See OBD Clearinghouse or Suzuki service information. |
| Toyota | 2000-2006 | All models | Fail for monitor readiness. | Monitors can be difficult to complete. | Follow drive cycle. See Toyota service information. |
| Toyota | 2003-2004 | 4 Runner | Vehicle Stability Control (VSC) light may illuminate if CAN protocol attempted with aftermarket scan tool. | Vehicle loses stability control calibration when CAN protocol attempted. Follow service procedure to reset zero-point calibration. | OIS will not attempt to communicate via CAN protocol on these vehicles. |
| Toyota | 2007 | Highlander Hybrid | Fail for oxygen sensor (air/fuel) monitor readiness. | Air Fuel monitor issue. Perform software update to vehicle at no charge per Toyota Special Service Campaign F0P, dated August 20, 2015 and TSB #0042-15. | If fails for incomplete oxygen sensor monitor, advise motorist recall may be required. Recall status: use https://www.toyota.com/recall. |
| Volvo | 2000 | S40 / V40 | Failure to set Comprehensive, Oxygen sensor, and Catalyst monitors. | Defective ECM. | Send to Referee for inspection only if comprehensive, oxygen sensor, and catalyst monitors unset. If any additional failures exist, they must be repaired before the Referee inspection. |
| Volvo | 2004-2006 | S40, V50 | Air conditioning readiness monitor mistakenly set to supported instead of unsupported. | Vehicle design anomaly. | OIS ignores A/C monitor status. |
| Volvo | 2005-2007 | XC90 | Air conditioning readiness monitor mistakenly set to supported instead of unsupported. | Vehicle design anomaly. | OIS ignores A/C monitor status. |
| VW | 2000-2005 | Passat | May fail for no OBD communication. No response or Only Transmission Control Module responds to DADs requests. ABS and/or brake lamp illuminated in instrument panel cluster | Broken ground bond wire in ABS module causes diagnostic communication issues with the ABS module, ECM, and TCM. Diagnose and repair per VW TSB #45 15 01, dated September 21, 2015. | Likely Broken Vehicle Repair and Retest. |
This table details specific vehicles that may encounter issues during OBD testing. Inspectors should consult this list when encountering problems, as the OIS system may have specific programming to handle these known anomalies, or the vehicle may require specific repairs or software updates. For instance, certain Ford and Lincoln models from 2020-2023 may experience communication issues with BAR-OIS due to a software design issue, requiring a dealership software update. Similarly, some GM vehicles might trigger “no vehicle voltage” prompts, often resolvable with auxiliary power to the OBDII connector.
Permanent Diagnostic Trouble Code Vehicles of Interest
Some vehicles are known to have issues with clearing Permanent Diagnostic Trouble Codes (PDTCs). In these cases, even after the underlying issue is resolved, the PDTC may persist, causing the vehicle to fail inspection. BAR-OIS is programmed to ignore PDTCs for the following vehicles:
| Make | Year | Model Engine (L); Fuel Type | Issue | Cause and Possible Remedy | Instructions to Inspector |
|---|---|---|---|---|---|
| Audi | 2010 | Q7; 3.0 (TDI/diesel) | Permanent Fault Codes P0087, P0088, and P053F will not clear if present. | No remedy is available. | Test normally. BAR-OIS ignores these codes. |
| Audi | 2011-2012 | Q7; 3.0 (TDI/diesel) | Permanent Fault Codes P0087, P0088, P053F, P064A, P2635, and P0230 will not clear if present. | No remedy is available. | Test normally. BAR-OIS ignores these codes. |
| Chrysler | 2011-2015 | 200; 2.4, 3.6 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Chrysler | 2010-2014 | 300; 3.6, 5.7, 6.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Chrysler | 2017 | Pacifica Hybrid | Vehicle fails for PDTC C2200 or B22A9-00. | Reflash modules per TSB 08-005-21 and 08-006-21 | Reflash then retest. |
| Chrysler | 2018 | Pacifica Hybrid | Vehicle fails for PDTC C2200 or B22A9-00. | Reflash modules per TSB 08-008-21 and 08-009-21 | Reflash then retest. |
| Chrysler | 2019 | Pacifica Hybrid | Vehicle fails for PDTC C2200 or B22A9-00. | Reflash modules per TSB 08-011-21 and 08-012-21 | Reflash then retest. |
| Chrysler | 2011-2015 | Town and Country; 3.6 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2014 | Avenger | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2012 | Caliber; 2.0, 2.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2015 | Challenger; 3.6, 5.7, 6.4 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2014 | Charger; 3.6, 5.7, 6.4 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2015 | Grand Caravan; 3.6 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2010-2011 | Dakota; 3.7, 4.7 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2013 | Dart; 2.0 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V50 and V51. | Reflash then retest. |
| Dodge | 2013 | Dart; 2.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2014-2015 | Dart; 2.0, 2.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2014 | Durango; 3.6, 5.7 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2011-2015 | Journey; 2.4, 3.6 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Dodge | 2010-2011 | Nitro; 3.7, 4.0 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Ford | 2011-2014 | Mustang; 3.7 & 5.0 (gasoline) | Vehicle fails for Permanent Fault Code P0315. | Vehicle not self-clearing permanent fault code. | Refer the motorist to Ford for Customer Satisfaction Program 17N01. |
| Freightliner | 2014-2015 | Sprinter 2500 Sprinter 3500 (diesel) | Vehicle fails for Permanent Fault Codes P202A, P203A, P208A, P20B9, P20BD, P20BE or P20FA. | Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore these codes. |
| Jeep | 2014-2015 | Cherokee; 2.4, 3.2 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V51. | Reflash then retest. |
| Jeep | 2010 | Commander; 5.7 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Jeep | 2010-2015 | Grand Cherokee; 3.6, 5.7, 6.4 | Permanent Fault Codes will not clear | Reflash per Recall V51. | Reflash then retest. |
| Jeep | 2014-2017 | Grand Cherokee (diesel) | Vehicle fails for Permanent Fault Code P1D30. | Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore this code. |
| Jeep | 2010-2012 | Liberty; 3.7 | Permanent Fault Codes will not clear | Reflash per Recall V51. | Reflash then retest. |
| Jeep | 2011-2015 | Patriot / Compass; 2.0, 2.4 | Permanent Fault Codes will not clear | Reflash per Recall V51. | Reflash then retest. |
| Jeep | 2010-2015 | Wrangler; 3.6, 3.8 | Permanent Fault Codes will not clear | Reflash per Recall V51. | Reflash then retest. |
| Mercedes | 2010-2013 | 350 Bluetec | Vehicle fails for Permanent Fault Codes P203D, P20B6, P20BD or P20BE | Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore these codes. |
| Mercedes | 2014-2015 | Sprinter 2500 Sprinter 3500 (diesel) | Vehicle fails for Permanent Fault Codes P202A, P203A, P208A, P20B9, P20BD, P20BE or P20FA. | Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore these codes. |
| Ram | 2010-2014 | 1500; 3.6, 3.7, 4.7, 5.7 | Vehicle fails for Permanent Fault Code U0140. | Reflash per Recall V51. | Reflash then retest. |
| Ram | 2013 | 1500; 3.6, 5.7 | Permanent Fault Codes will not clear. | Reflash per Recall V50. | Reflash then retest. |
| Ram | 2014-2017 | 1500 (diesel) | Vehicle fails for Permanent Fault Code P1D30. | Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore this code. |
| Ram | 2010-2015 | 2500; 5.7, 6.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Ram | 2011-2015 | 3500 Cab Chassis; 5.7, 6.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Ram | 2013-2015 | 3500 Pickup; 5.7, 6.4 | Permanent Fault Codes will not clear. | Reflash per Recall V51. | Reflash then retest. |
| Ram | 2014 | Promaster; 3.6 | Permanent Fault Codes will not clear. | Reflash per Recall V50. | Reflash then retest. |
| Volkswagen | 2010 | Touareg; 3.0 (TDI/diesel) | Permanent Fault Codes P20B5, P0087, P0088, and P053F will not clear if present. | No remedy is available. | Test normally. BAR-OIS ignores these codes. |
| Volkswagen | 2011-2012 | Touareg; 3.0 (TDI/diesel). | Permanent Fault Codes P20B5, P0087, P0088, P053F, P064A, P2635, and P0230 will not clear if present. | No remedy is available. | Test normally. BAR-OIS ignores these codes. |
Inspectors working with these vehicles should be aware of these exceptions and follow the “Instructions to Inspector” column in the table. Often, the resolution involves a software reflash at the dealership. For certain Audi and Volkswagen diesel models (2010-2012), specific PDTCs are known to not clear, and the BAR-OIS system is programmed to ignore these codes to allow these vehicles to pass inspection if no other issues are present.
BAR-97 EIS Vehicles of Interest
For older vehicles (model year 1996-1999) undergoing BAR-97 EIS inspections, similar monitor readiness issues may arise. In many cases, the BAR-97 EIS is programmed to accommodate these design anomalies by ignoring readiness status.
| Make | Year | Model Engine (L); Fuel Type | Issue | Cause and Possible Remedy | Instructions to Inspector |
|---|---|---|---|---|---|
| BMW | 1996 | 7-Series, 8-Series 5.0L, 5.4L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Chrysler | 1996 | Cirrus, Concord, LHS Sebring Convertible | All monitors reset to incomplete upon every ignition key-off. | Recall campaign #678 applies to California certified vehicles originally sold in California. TSB #18-005-01 (with lifetime warranty) applies to federal certified and California certified originally sold in northeast states. | Comply with recall, then test as normal. |
| Chrysler | 1996 | Concord, LHS, New Yorker, Sebring, Town & Country 2.0L, 2.4L, 2.5L, 3.3L, 3.5L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Chrysler | 1998-1999 | Town & Country 3.3L Flex Fuel | Monitors may not function when ethanol is detected by the vehicle. | Test as normal. | |
| Dodge | 1996 | Stratus, Intrepid, Neon | All monitors reset to incomplete upon every ignition key-off. | Recall campaign #678 applies to California certified vehicles originally sold in California. TSB #18-005-01 (with lifetime warranty) applies to federal certified and California certified originally sold in northeast states. | Comply with recall, then test as normal. |
| Dodge | 1996 | Avenger, Stratus 2.0L manual | Monitors difficult to complete. | EIS ignores readiness status. | |
| Dodge | 1996 | Stealth 3.0L | All monitors reset to incomplete upon every ignition key-off. | These vehicles are not reflashable. | EIS ignores readiness status. |
| Dodge | 1998-1999 | Caravan 3.3L Flex Fuel | Monitors may not function when ethanol is detected by the vehicle. | Test as normal. | |
| Eagle | 1996 | Vision | All monitors reset to incomplete upon every ignition key-off. | Recall campaign #678 applies to California certified vehicles originally sold in California. TSB #18-005-01 (with lifetime warranty) applies to federal certified and California certified originally sold in northeast states. | Comply with TSB, then test as normal. |
| Eagle | 1996-1997 | Talon 2.0L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Ford | 2020-2022 | F-53 Motorhome, F-59 Commercial Stripped Chassis; Gasoline (not hybrid) | May fail for no OBD communication. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. |
| Ford | 2021-2023 | F-650, F-750; all engines; Gasoline (not hybrid) | May fail for no OBD communication. | Design issue. Software update available. | Test normally. If the vehicle you are inspecting fails the OBD test for no communication, direct the vehicle to a Ford dealership for a software update. Issue may be due to software in gateway module—see SSM 50974. |
| Hyundai | 1996 | Accent 1.5L Elantra 1.8L Sonata 2.0L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Hyundai | 1997-1998 | Sonata 2.0L, 3.0L | Monitors difficult to complete. | EIS ignores readiness status. | |
| lnfiniti | 1996 | All models | Catalyst and evaporative system monitors are difficult to complete. | Follow drive cycle for specific vehicle model per TSB #ITB98-011F, June 7, 2013. | Test as normal. |
| Kia | 1996 | Sephia Sportage | Monitors difficult to complete. | EIS ignores readiness status. | |
| Lexus | 1996-1999 | All models | Monitors can be difficult to complete. | Follow drive cycles in Lexus service information. | Test as normal. |
| Mercedes-Benz | 1996 | C220, E320, C280, S320, SL320 | The MIL illuminates when a scan tool is connected to the DLC. Trouble codes are not stored. | If the OBD II connector is used as the RPM source during the Smog Check, the MIL will illuminate. | Do not connect the OBD II connector until the analyzer prompts for the OBD II functional test. Use the conventional contact or non-contact method to obtain an rpm signal. |
| Mitsubishi | 1996-1997 | All Models | Monitors difficult to complete. | EIS ignores readiness status. | |
| Mitsubishi | 1998 | Eclipse (all), Galant 2.4L, Mirage, Montero Sport 2.4L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Mitsubishi | 1998 | 3000GT, Diamante, Galant 2.3L, Montero, Montero Sport 3.0L | Some monitors are difficult to complete. | Follow recommended drive cycles in Mitsubishi service manual. | Test as normal. |
| Mitsubishi | 1999 | All models | Some monitors are difficult to complete. | Follow recommended drive cycles in Mitsubishi service manual. | Test as normal. |
| Nissan | 1996 | Sentra 1.6L and 2.0L manual, 200SX 1.6L, 240SX 2.4L, Maxima 3.0L, Pickup 2.4L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Nissan | 1996-1997 | All models | Catalyst and evaporative system monitors are difficult to complete. | Follow recommended drive cycle for specific model per Nissan TSB #NTB98-018G, June 7, 2013. | Comply with TSB, then test as normal. |
| Nissan | 1999 | All models | Monitors can be difficult to complete. | Follow owner’s manual drive cycle to achieve readiness. | Test as normal. |
| Plymouth | 1996 | Breeze, Neon | All monitors reset to incomplete upon every ignition key-off. | Recall campaign #678 applies to California certified vehicles originally sold in California. TSB #18-005-01 (with lifetime warranty) applies to federal certified and California certified originally sold in northeast states. | Comply with recall, then test as normal. |
| Plymouth | 1998-1999 | Voyager 3.3L Flex Fuel | Monitors may not function when ethanol is detected by the vehicle. | Test as normal. | |
| Saab | 1996-1998 | 900 2.3L (B234 with Motronic 4.1) | Monitors difficult to complete. | EIS ignores readiness status. | |
| Saab | 1996-1998 | All models | Catalyst and evaporative system monitors are difficult to complete. | Saab Service Instruction No. 248-9037 describes the correct drive cycle for completion of the monitors. | Comply with TSB, then test as normal. |
| Subaru | 1996 | All models | Readiness cleared at key-off. | EIS ignores readiness status. | |
| Toyota | 1996-1999 | All models | Monitors can be difficult to complete. | Follow drive cycles in Toyota service information. | Test as normal. |
| Toyota | 1996-1997 | Tercel, Paseo | Evaporative system monitor will never complete or is unsupported. | The EIS allows any one monitor to be incomplete. Test as normal. | |
| VW | 1997-1999 | Passat | May fail for no OBD communication. No response or Only Transmission Control Module responds to DADs requests. ABS and/or brake lamp illuminated in instrument panel cluster. | Broken ground bond wire in ABS module causes diagnostic communication issues with the ABS module, ECM, and TCM. Diagnose and repair per VW TSB #45 15 01, dated September 21, 2015. | Likely Broken Vehicle. Repair and retest. |
| Volvo | 1996-1998 | All models | Monitors difficult to complete. | Follow recommended drive cycles in Service Bulletin 25-19 | EIS ignores readiness status. |
For many 1996-1999 vehicles, particularly from manufacturers like Chrysler, Dodge, Eagle, Hyundai, Kia, Mitsubishi, Nissan, Plymouth, Saab, Subaru, Toyota, and Volvo, monitors may be inherently difficult to complete, or the readiness status might reset every ignition cycle. In these scenarios, the BAR-97 EIS system is designed to disregard readiness monitor status, focusing on other aspects of the OBD test. For specific models like Mercedes-Benz C-Class and E-Class from 1996, the MIL may illuminate when a scan tool is connected; inspectors should be aware of this and use alternative RPM measurement methods initially, connecting the OBD tool only when prompted.
IV. Conclusion
Understanding obd2 vehicle monitors and their role in vehicle diagnostics and emission testing is crucial for both vehicle owners and automotive professionals. This guide provides a detailed reference for navigating OBD2 testing, interpreting pass/fail standards, and addressing common issues, particularly for vehicles known to have specific OBD-related challenges. By staying informed about these vehicle-specific considerations and following the outlined instructions, technicians can effectively perform smog checks and ensure vehicles meet emission compliance standards, contributing to cleaner air and a healthier environment. For further in-depth information and updates, always consult resources like obd-de.com and official vehicle manufacturer service information.
