As an automotive repair expert at obd-de.com, understanding On-Board Diagnostics (OBD) is crucial for effective vehicle maintenance and repair. This guide serves as a comprehensive reference for navigating the complexities of OBD-II and EOBD systems, particularly focusing on pass/fail standards for emissions testing and utilizing Auto Drive Obd2/eobd Code Readers for efficient diagnostics. This document is designed to be an enhanced and SEO-optimized version of the original “On-Board Diagnostic Test Reference,” tailored for an English-speaking audience seeking in-depth information and practical advice.
Understanding OBD Test Standards: A Deep Dive
The journey into modern automotive diagnostics begins with understanding the standardized systems designed to monitor vehicle performance and emissions – OBD-II and its European counterpart, EOBD. These systems are pivotal in ensuring vehicles meet stringent environmental regulations and operate efficiently. For automotive technicians and car enthusiasts alike, a solid grasp of OBD standards is essential. This guide breaks down the key aspects of OBD testing, focusing on how to interpret test results and leverage auto drive OBD2/EOBD code readers for effective troubleshooting.
Pass/Fail Standards for OBD Emissions Testing
Emissions testing is a critical aspect of vehicle inspections, and OBD systems play a central role in this process. The OBD test portion of a Smog Check inspection, for instance, relies on specific pass/fail criteria to determine a vehicle’s emission control system health. Let’s delve into the standards that dictate whether a vehicle passes or fails based on its OBD system performance.
Readiness Monitor Standards
Readiness monitors are self-diagnostic tests run by a vehicle’s OBD system to confirm the functionality of emission control components. These monitors ensure that systems like the catalytic converter, oxygen sensors, and evaporative systems are operating correctly. While many vehicles complete these monitors during normal driving, some require specific driving conditions, often detailed in OEM service literature or repair industry guides. These “drive cycles” involve specific speeds, temperatures, engine loads, and other parameters, sometimes necessitating dynamometer equipment for proper execution.
It’s important to note that readiness monitor completion is contingent on properly functioning components. A vehicle may fail to set a monitor if underlying issues prevent the test from running successfully. Furthermore, any repair work involving battery disconnection or emission component replacement necessitates rerunning these readiness monitors.
The number of incomplete readiness monitors allowed for a passing OBD test varies based on the vehicle’s model year and fuel type. Here’s a breakdown:
| Model Year | Fuel Type | Incomplete Monitors Allowed to Pass OBD Test |
|---|---|---|
| 1996-1999 | Gas (Gasoline, Propane, Natural Gas) | Any one |
| 2000 and newer | Gas (Gasoline, Propane, Natural Gas) | Evaporative system only |
| 1998-2006 | Diesel | Zero |
| 2007 and newer | Diesel | Particulate Filter and NMHC (Non-Methane HydroCarbon) |
Image: An OBD-II port, the gateway to vehicle diagnostics, highlighting its accessibility for code readers.
Understanding the Table: This table is crucial for technicians performing smog checks. For older gasoline vehicles (1996-1999), only one incomplete monitor is permitted. For newer gasoline vehicles, only an incomplete evaporative system monitor is acceptable. Diesel vehicles have stricter standards, especially post-2007 models, where only the Particulate Filter and NMHC monitors can be incomplete. Using an auto drive OBD2/EOBD code reader, technicians can quickly check the status of these monitors before an official smog test, saving time and ensuring vehicles are likely to pass.
Malfunction Indicator Lamp (MIL) Standards
The Malfunction Indicator Lamp (MIL), commonly known as the “Check Engine” light, is a primary indicator of potential emission control issues. OBD testing includes stringent standards regarding the MIL’s behavior:
| Condition | Pass/Fail | Standard |
|---|---|---|
| MIL illuminates when key is on, engine off (KOEO) | Pass | System check – normal operation. |
| MIL turns off when engine is running (KOER) | Pass | No active emission faults detected during engine operation. |
| MIL does not illuminate when key is on, engine off (KOEO) | Fail | Bulb check failure or system malfunction. |
| MIL illuminates when engine is running (KOER) | Fail | Active emission fault detected – requires diagnosis and repair. |
MIL Operation and Diagnostics: A properly functioning MIL should illuminate briefly when the ignition is turned to the “ON” position before starting the engine (KOEO) to indicate the bulb is working. It should then turn off once the engine is running (KOER) if no emission-related faults are present. If the MIL stays illuminated while the engine is running, it signifies a problem that needs attention. An auto drive OBD2/EOBD code reader becomes invaluable here, allowing technicians to retrieve Diagnostic Trouble Codes (DTCs) that pinpoint the source of the MIL illumination.
Communication Standards
Successful OBD testing hinges on establishing reliable communication between the diagnostic tool and the vehicle’s computer. Communication failures can stem from various issues, including connector damage, wiring problems, aftermarket stereo installations interfering with the system, or even the tool mistakenly communicating with the transmission computer instead of the engine computer.
| Test Type | Standard |
|---|---|
| BAR-97 | Vehicle communicates with BAR-97 testing equipment. |
| OIS | Vehicle communicates with OIS and transmits required data (Mode $01 PID $00, Mode $01 PID $01). |
Communication Troubleshooting: For a vehicle to pass the OBD communication portion of a smog check, it must successfully communicate with the testing equipment. Mode $01 PID $00 queries the vehicle for supported data parameters, while Mode $01 PID $01 retrieves essential data like MIL status, DTCs, and monitor status. If communication fails, technicians should first inspect the OBD connector and wiring. An auto drive OBD2/EOBD code reader can also help verify basic communication before a formal smog test, and some advanced readers can diagnose communication issues.
Permanent Diagnostic Trouble Code (PDTC) Standards
Permanent Diagnostic Trouble Codes (PDTCs) were introduced to prevent clearing of emission-related DTCs before the underlying issue is properly resolved. Unlike regular DTCs, PDTCs cannot be erased using a scan tool or by disconnecting the battery. They are only cleared by the OBD-II system itself after verifying that the fault condition is no longer present, typically after one or more successful drive cycles.
| Model Year | Standard |
|---|---|
| 1996-2009 | Not applicable |
| 2010 and newer | Vehicles fail if a PDTC is present |
PDTC Implications for Testing: Since July 1, 2019, PDTC checks have been part of BAR-OIS Smog Check inspections. For vehicles model year 2010 and newer, the presence of a PDTC will result in a failed smog check, regardless of whether the MIL is currently illuminated. However, there’s an exception: PDTC presence is ignored if the vehicle has completed at least 15 warm-up cycles and been driven 200 miles since the last OBD data clear. Auto drive OBD2/EOBD code readers are essential for identifying PDTCs. Technicians should be aware that some vehicles are known to have issues clearing certain PDTCs, and manufacturers may have issued recalls or extended warranties to address these problems.
Modified Software Standards
Tampering with a vehicle’s software for emission control is a serious violation. Since July 19, 2021, smog checks include a modified software check. Software modifications not approved by the California Air Resources Board (CARB) will lead to a failed inspection.
Software Integrity and Smog Checks: Vehicles identified with illegally modified software will fail the smog check, with the Vehicle Inspection Report indicating “Modified Software.” To pass, the vehicle must be restored to an OEM-approved or CARB-approved software configuration. While auto drive OBD2/EOBD code readers primarily focus on DTCs and system monitoring, software integrity checks are typically performed by the inspection system itself.
Vehicles of Interest: Navigating Known OBD Test Issues
Certain vehicle makes and models are known to exhibit specific issues during OBD testing. These issues can range from communication problems and incomplete readiness monitors to false MIL illuminations and difficulties clearing PDTCs. The following sections detail vehicles of interest, categorized by the type of OBD inspection and the nature of the problem. Understanding these vehicle-specific issues is crucial for efficient diagnostics and repair, and auto drive OBD2/EOBD code readers are indispensable tools for technicians encountering these challenges.
OIS Vehicles of Interest: Common OBD Issues and Solutions
The following table outlines gasoline, flex-fuel (model year 2000 and newer), and diesel (model year 1998 and newer) vehicles known to have OBD test issues during an OIS inspection. These issues include no communication, readiness monitor problems, OBD test incompatibility, and false MIL illumination. In many cases, the OIS system is programmed to accommodate these anomalies, but sometimes vehicle repair is necessary.
| 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, 323iT Touring, 323Ci Coupe, 323 Cic Convertible, 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, built 3/98 – 7/99, built 2/99 – 7/99, built 9/98 – 7/99, built 4/99 – 7/99 | Various Models | 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, Z8 & M5 with S62 engine, 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 & GMC | 2000-2002 | S-10 (2WD), 2.2L I-4 (E85), 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. | OIS ignores all 11 readiness monitors. |
| Chevrolet & GMC | 2000-2005 | Suburban, Silverado, Express, Avalanche (gasoline) [Federal certified], 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 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 & GMC | 2002 | Silverado C/K 2500HD (diesel), Sierra 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 & GMC | 2019 | Express 2.8L (diesel) [California certified], 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. |
| Chrysler, Dodge, Plymouth | 1999-2000 | Town & Country, Caravan, 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. |
| Chrysler, Plymouth | 2000 | Town and Country 3.3L V-6 (E-85), 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. |
| 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, Dodge | 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, Ford, Freightliner, GMC, Isuzu, Mitsubishi Fuso, Nissan | 1998-2006, 1998-2004, 1998-2004, 1998-2005, 1998-2005, 1998-2004, 1999-2007 | Various Diesel Models over 8,500 GVWR [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 | 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, Freightliner | 2004-2006 | 2500 3500 Sprinter (diesel), 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, 2015, 2016 | ProMaster 2500 & 3500 High 3.0L (diesel) [California certified], ProMaster 1500, 2500, & 3500 High & Standard 3.0L (diesel) [California certified], 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., Recall V97 and ZC0., 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 | 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, Lincoln | 2011 | Edge, Explorer 3.5L & 3.7L, 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. |
| 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, Lincoln | 2020-2022 | Escape; all engines; Gasoline and hybrid, Bronco Sport; all engines; Gasoline (not hybrid), E350, E450; all engines; Gasoline (not hybrid), Corsair; all engines; Gasoline and hybrid, F-53 Motorhome, F-59 Commercial Stripped Chassis; Gasoline (not hybrid), F-650, F-750; 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. |
| 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 | 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, Nissan | 2000 -2001 | I30, Maxima | Failure to set catalyst monitor. | Only OEM scan tool shows OBD catalyst code. | Test catalyst and replace if defective. |
| Infiniti, Nissan | 2000 -2001, 2000-2006 | I30, All models | Fail for readiness. | Vehicle has difficulty completing all monitors during normal driving., 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. | Run drive cycle., Follow drive cycle. See owner’s manual. |
| Isuzu, Mazda | 2000-2002, 2002-2003 | Hombre (2WD) 2.2L I-4 (E85), B3000 (2WD) 3.0L V-6 (E-85) | 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), Readiness monitors will not set on certain flex fuel models. | 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., 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., OIS ignores all 11 readiness monitors. |
| Jaguar, Land Rover | 2017, 2018, 2019, 2017, 2018, 2019 | Jaguar XE, XF, & F-Pace 2.0L (diesel) [California certified] Test Group HJLXJ02.0STY, Jaguar XE, XF, F-Pace & Rover Velar 2.0L (diesel) [California certified] Test group JJLXJ02.0STY, Jaguar XE, XF, & F-Pace 2.0L (diesel) [California certified] Test group KJLXJ02.0STY, Discovery, Range Rover, Range Rover Sport 3.0L (diesel)[California certified] Test group HJLXT03.0GTR, Velar 2.0L (diesel) [California certified] Test group JJLXJ02.0STY, Velar 2.0L (diesel) [California certified] Test group KJLXJ02.0STY | NOx Aftertreatment System monitor will not complete. | Vehicle design anomaly. Dealer issued recall H444., Vehicle design anomaly. Dealer issued recall H444., Vehicle design anomaly. Dealer issued recall H444., Vehicle design anomaly. Dealer issued recall N808., Vehicle design anomaly. Dealer issued recall N808., 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 Jaguar dealership for a software update., 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., 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., 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., 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., 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. |
| 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. |
| Lexus, Toyota | 2007 | RX400 Hybrid, Highlander Hybrid | Fail for oxygen sensor (air/fuel) monitor readiness. Air conditioning readiness monitor mistakenly set to supported instead of unsupported., Fail for oxygen sensor (air/fuel) monitor readiness. | Air Fuel monitor issue. Perform software update to vehicle at no charge per Lexus campaign FLD with TSB #L-SB-0027-15., 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., If fails for incomplete oxygen sensor monitor, advise motorist recall may be required. Recall status: use https://www.toyota.com/recall. |
| 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 | 2003-2004, 2005 | Mazda 6, 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., 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., 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 | 2000-2001, 1998, 1998, 1999 | Montero, Montero Sport, Diamante, 3000GT Mirage, Galant, Expo/Expo LRV, and Eclipse models (except 2.0L non—turbo 420A engine models)., Eclipse (all), Galant 2.4L, Mirage, Montero Sport 2.4L, 3000GT, Diamante, Galant 2.3L, Montero, Montero Sport 3.0L, All models | Fail for monitor readiness., Monitors difficult to complete., Some monitors are difficult to complete., Some monitors are difficult to complete. | Some monitors are difficult to complete., Monitors difficult to complete., Follow recommended drive cycles in Mitsubishi service manual., Follow recommended drive cycles in Mitsubishi service manual. | Follow recommended drive cycles. See Mitsubishi service manual., EIS ignores readiness status., Test as normal., Test as normal. |
| Toyota | 2000-2006, 2003-2004 | All models, 4 Runner | Fail for monitor readiness., Vehicle Stability Control (VSC) light may illuminate if CAN protocol attempted with aftermarket scan tool. | Monitors can be difficult to complete., Vehicle loses stability control calibration when CAN protocol attempted. Follow service procedure to reset zero-point calibration. | Follow drive cycle. See Toyota service information., OIS will not attempt to communicate via CAN protocol on these vehicles. |
| 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, 2005-2007 | S40, V50, XC90 | Air conditioning readiness monitor mistakenly set to supported instead of unsupported. | Vehicle design anomaly. | OIS ignores A/C monitor status., OIS ignores A/C monitor status. |
| VW | 2000-2005, 1997-1999 | Passat, 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, 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., 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., Likely Broken Vehicle. Repair and retest. |
Using Code Readers for OIS Vehicle Issues: For many of these vehicles, an auto drive OBD2/EOBD code reader can be the first step in diagnosis. For instance, with Audi and VW models experiencing no communication due to ABS module issues, a code reader might fail to connect, immediately indicating a deeper problem beyond simple DTCs. For BMW models with oxygen sensor readiness issues, a code reader can confirm monitor status and guide technicians to check for applicable software updates or recalls. Similarly, for Chevrolet and GMC models with “Unable to confirm OBDII requirements” messages, a code reader can help verify basic OBD-II functionality before proceeding with a BAR-97 test if needed.
Image: A technician using an OBD-II code reader, demonstrating the practical application of diagnostic tools.
Note: This table provides a snapshot of known issues. Always consult the latest service bulletins and repair information from vehicle manufacturers for the most up-to-date diagnostic and repair procedures.
Permanent Diagnostic Trouble Code Vehicles of Interest
Certain vehicles are known to have persistent PDTC issues, where specific codes may not clear even after the fault is resolved. In these cases, BAR-OIS may ignore these codes to allow the vehicle to pass inspection.
| Make | Year | Model Engine (L); Fuel Type | Issue | Cause and Possible Remedy | Instructions to Inspector |
|---|---|---|---|---|---|
| Audi, Volkswagen | 2010, 2011-2012, 2010, 2011-2012 | Q7; 3.0 (TDI/diesel), Q7; 3.0 (TDI/diesel), Touareg; 3.0 (TDI/diesel), Touareg; 3.0 (TDI/diesel). | Permanent Fault Codes P0087, P0088, and P053F will not clear if present., Permanent Fault Codes P0087, P0088, P053F, P064A, P2635, and P0230 will not clear if present., Permanent Fault Codes P20B5, P0087, P0088, and P053F will not clear if present., Permanent Fault Codes P20B5, P0087, P0088, P053F, P064A, P2635, and P0230 will not clear if present. | No remedy is available., No remedy is available., No remedy is available., No remedy is available. | Test normally. BAR-OIS ignores these codes., Test normally. BAR-OIS ignores these codes., Test normally. BAR-OIS ignores these codes., Test normally. BAR-OIS ignores these codes. |
| Chrysler, Dodge, Ram, Jeep | 2011-2015, 2010-2014, 2017, 2018, 2019, 2011-2014, 2011-2012, 2011-2015, 2011-2014, 2011-2015, 2010-2011, 2013, 2013, 2014-2015, 2011-2014, 2011-2015, 2010-2011, 2010, 2010-2015, 2014-2017, 2010-2012, 2011-2015, 2010-2015, 2010-2014, 2013, 2014-2017, 2010-2015, 2011-2015, 2013-2015, 2014 | Various Models and Engines | Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Vehicle fails for PDTC C2200 or B22A9-00., Vehicle fails for PDTC C2200 or B22A9-00., Vehicle fails for PDTC C2200 or B22A9-00., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Vehicle fails for Permanent Fault Code U0140., Vehicle fails for Permanent Fault Code U0140., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Vehicle fails for Permanent Fault Code U0140., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Vehicle fails for Permanent Fault Code U0140., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear, Vehicle fails for Permanent Fault Code P1D30., Permanent Fault Codes will not clear, Permanent Fault Codes will not clear, Permanent Fault Codes will not clear, Vehicle fails for Permanent Fault Code U0140., Permanent Fault Codes will not clear., Vehicle fails for Permanent Fault Code P1D30., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear., Permanent Fault Codes will not clear. | Reflash per Recall V51., Reflash per Recall V51., Reflash modules per TSB 08-005-21 and 08-006-21, Reflash modules per TSB 08-008-21 and 08-009-21, Reflash modules per TSB 08-011-21 and 08-012-21, Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V50 and V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51, Vehicle not self-clearing permanent fault code., Reflash per Recall V51, Reflash per Recall V51, Reflash per Recall V51, Reflash per Recall V51., Reflash per Recall V50., Vehicle not self-clearing permanent fault code., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V51., Reflash per Recall V50. | Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Test normally. BAR-OIS will ignore this code., Test normally. BAR-OIS will ignore this code., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Reflash then retest., Test normally. BAR-OIS will ignore this code., Reflash then retest., Reflash then retest., Reflash then retest., 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, Mercedes | 2014-2015, 2014-2015, 2010-2013 | Sprinter 2500 Sprinter 3500 (diesel), Sprinter 2500 Sprinter 3500 (diesel), 350 Bluetec | Vehicle fails for Permanent Fault Codes P202A, P203A, P208A, P20B9, P20BD, P20BE or P20FA., Vehicle fails for Permanent Fault Codes P202A, P203A, P208A, P20B9, P20BD, P20BE or P20FA., Vehicle fails for Permanent Fault Codes P203D, P20B6, P20BD or P20BE | Vehicle not self-clearing permanent fault code., Vehicle not self-clearing permanent fault code., Vehicle not self-clearing permanent fault code. | Test normally. BAR-OIS will ignore these codes., Test normally. BAR-OIS will ignore these codes., Test normally. BAR-OIS will ignore these codes. |
PDTCs and Code Readers: Auto drive OBD2/EOBD code readers are critical for identifying PDTCs. When diagnosing vehicles, technicians should check for both regular DTCs and PDTCs. If a PDTC is present on a vehicle from model year 2010 or newer, it will likely cause a smog check failure unless it falls under the exceptions listed or is one of the known problematic codes that BAR-OIS ignores. For Chrysler, Dodge, Jeep, and Ram vehicles listed, software reflashing is often the remedy for persistent PDTC issues, highlighting the importance of staying updated with manufacturer recalls and technical service bulletins.
BAR-97 EIS Vehicles of Interest: Readiness Monitor Challenges in Older Models
For older vehicles (model year 1996-1999) undergoing BAR-97 EIS inspections, readiness monitor issues are common. In many cases, the BAR-97 EIS system is designed 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, Dodge, Eagle, Plymouth | 1996 | Cirrus, Concord, LHS Sebring Convertible, Stratus, Intrepid, Neon, Vision, 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., 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., 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., 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., 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., 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., 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., 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., 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., Comply with recall, then test as normal., Comply with recall, then test as normal., Comply with recall, then test as normal., Comply with recall, then test as normal., Comply with recall, then test as normal., Comply with TSB, then test as normal., Comply with recall, then test as normal., Comply with recall, then test as normal. |
| Chrysler | 1996, 1998-1999 | Concord, LHS, New Yorker, Sebring, Town & Country 2.0L, 2.4L, 2.5L, 3.3L, 3.5L, Town & Country 3.3L Flex Fuel | Monitors difficult to complete., Monitors may not function when ethanol is detected by the vehicle. | EIS ignores readiness status., Test as normal. | |
| Dodge | 1996, 1996, 1996, 1998-1999 | Avenger, Stratus 2.0L manual, Stealth 3.0L, Caravan 3.3L Flex Fuel | Monitors difficult to complete., Monitors difficult to complete., All monitors reset to incomplete upon every ignition key-off., Monitors may not function when ethanol is detected by the vehicle. | EIS ignores readiness status., EIS ignores readiness status., These vehicles are not reflashable., Test as normal. | |
| Eagle | 1996-1997 | Talon 2.0L | Monitors difficult to complete. | EIS ignores readiness status. | |
| Ford | 2020-2022, 2021-2023 | F-53 Motorhome, F-59 Commercial Stripped Chassis; Gasoline (not hybrid), 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., 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, 1997-1998 | Accent 1.5L Elantra 1.8L Sonata 2.0L, Sonata 2.0L, 3.0L | Monitors difficult to complete., Monitors difficult to complete. | EIS ignores readiness status., EIS ignores readiness status. | |
| Infiniti, Nissan, Saab | 1996, 1996-1997, 1996-1998, 1996-1998 | All models, All models, 900 2.3L (B234 with Motronic 4.1), All models | Catalyst and evaporative system monitors are difficult to complete., Catalyst and evaporative system monitors are difficult to complete., Monitors difficult to complete., Catalyst and evaporative system monitors are difficult to complete. | Follow drive cycle for specific vehicle model per TSB #ITB98-011F, June 7, 2013., Follow recommended drive cycle for specific model per Nissan TSB #NTB98-018G, June 7, 2013., EIS ignores readiness status., Saab Service Instruction No. 248-9037 describes the correct drive cycle for completion of the monitors. | Test as normal., Comply with TSB, then test as normal., EIS ignores readiness status., Comply with TSB, then test as normal. |
| Kia, Mitsubishi, Nissan, Saab, Subaru, Toyota, Volvo | 1996, 1996-1997, 1998, 1998, 1999, 1996, 1996-1997, 1998, 1999, 1996, 1996-1999, 1996-1997, 1996-1998 | Sephia Sportage, All Models, Eclipse (all), Galant 2.4L, Mirage, Montero Sport 2.4L, 3000GT, Diamante, Galant 2.3L, Montero, Montero Sport 3.0L, All models, All models, All models, All models, Tercel, Paseo, All models | Monitors difficult to complete., Monitors difficult to complete., Monitors difficult to complete., Monitors difficult to complete., Some monitors are difficult to complete., Some monitors are difficult to complete., Monitors difficult to complete., Monitors difficult to complete., Some monitors are difficult to complete., Some monitors are difficult to complete., Readiness cleared at key-off., Monitors can be difficult to complete., Evaporative system monitor will never complete or is unsupported., Monitors difficult to complete. | EIS ignores readiness status., EIS ignores readiness status., EIS ignores readiness status., EIS ignores readiness status., Follow recommended drive cycles in Mitsubishi service manual., Follow recommended drive cycles in Mitsubishi service manual., EIS ignores readiness status., Follow recommended drive cycles in Mitsubishi service manual., Follow recommended drive cycles in Mitsubishi service manual., Follow recommended drive cycles in Mitsubishi service manual., EIS ignores readiness status., Follow drive cycles in Toyota service information., The EIS allows any one monitor to be incomplete. Test as normal., Follow recommended drive cycles in Service Bulletin 25-19 | EIS ignores readiness status., EIS ignores readiness status., EIS ignores readiness status., EIS ignores readiness status., Test as normal., Test as normal., EIS ignores readiness status., Test as normal., Test as normal., Test as normal., EIS ignores readiness status., Test as normal., Test as normal., EIS ignores readiness status. |
| 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. | |
| Plymouth | 1998-1999 | Voyager 3.3L Flex Fuel | Monitors may not function when ethanol is detected by the vehicle. | 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. |
| 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. |
| 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. |
Older Vehicles and Readiness: For these older models, achieving readiness can be challenging. Auto drive OBD2/EOBD code readers can still be useful for checking readiness monitor status, although for many of these vehicles, the EIS system will disregard incomplete monitors. For models like the 1996 Mercedes-Benz C220 and E320, technicians must be aware of potential MIL illumination when connecting scan tools during smog checks and should use alternative RPM measurement methods. For 1996-1997 Toyota Tercel and Paseo models, the EIS accommodates the evaporative system monitor issue by allowing one incomplete monitor.
Conclusion: Mastering OBD Diagnostics with Code Readers
Understanding OBD-II and EOBD test standards is paramount for automotive professionals and anyone involved in vehicle maintenance. This guide has provided a detailed overview of these standards, highlighting pass/fail criteria for emissions testing and common issues encountered with specific vehicle makes and models.
Auto drive OBD2/EOBD code readers are indispensable tools in this diagnostic landscape. They empower technicians to:
- Verify readiness monitor status before official smog checks, ensuring vehicles are likely to pass.
- Retrieve Diagnostic Trouble Codes (DTCs) to pinpoint the root cause of MIL illumination and emission system faults.
- Identify Permanent Diagnostic Trouble Codes (PDTCs), understanding their implications for smog check outcomes.
- Troubleshoot communication issues and other OBD system anomalies.
- Efficiently diagnose vehicle-specific OBD problems, leveraging the knowledge of known issues and remedies.
By mastering OBD diagnostics and effectively utilizing auto drive OBD2/EOBD code readers, automotive professionals can enhance their efficiency, accuracy, and customer service, ensuring vehicles meet emission standards and operate optimally. As OBD systems become increasingly sophisticated, continuous learning and staying updated with the latest vehicle-specific information and diagnostic techniques are essential for success in the automotive repair industry.
