This guide provides a comprehensive overview of pass/fail criteria for the On-Board Diagnostic (OBD) test during a Smog Check inspection. It also offers detailed instructions for inspecting vehicles known to have OBD test difficulties, focusing on utilizing an Auto Drive Obdii Eobd Code Reader for diagnostics.
Understanding OBD Pass/Fail Standards
This information replaces the Smog Check OBDII Reference (Testability Issues) document, formerly known as Appendix J. It aims to equip technicians with the knowledge to effectively use an auto drive obdii eobd code reader to diagnose and resolve common OBD issues.
Readiness Monitor Requirements for OBDII EOBD Code Readers
Readiness monitors, self-tests run by the vehicle’s OBD system, confirm emission control functionality. An auto drive obdii eobd code reader can display the status of these monitors. While normal driving usually completes these tests, some vehicles require specific driving conditions. Occasionally, owner’s manuals provide guidance, but repair manuals or OEM resources often contain more detailed drive cycle information.
Using an auto drive obdii eobd code reader, technicians can verify monitor completion, which relies on functioning components. A thorough diagnosis and repair might be necessary before a monitor can run. Disconnecting the battery or replacing emission components requires rerunning readiness monitors.
Allowed Incomplete Monitors:
| Model Year | Fuel Type | Incomplete Monitors Allowed |
|---|---|---|
| 1996-1999 | Gas1 | Any one2 |
| 2000 and newer | Gas1 | Evaporative System2 |
| 1998-2006 | Diesel | Zero |
| 2007 and newer | Diesel | Particulate Filter and NMHC3 |
1 Includes gasoline, propane, natural gas (CNG, LNG, LPG).
2 Misfire, fuel, and comprehensive component continuous monitors are ignored for gas vehicles.
3 Implemented July 5, 2023.
Malfunction Indicator Lamp (MIL) Criteria
An auto drive obdii eobd code reader is crucial for interpreting MIL status. The MIL, or “Check Engine” light, provides critical information:
| Vehicle | Status | Standard |
|---|---|---|
| All OBDII | Pass | MIL ON with Key On, Engine Off (KOEO) |
| All OBDII | Pass | MIL OFF with Key On, Engine Running (KOER) |
| All OBDII | Fail | MIL OFF with KOEO |
| All OBDII | Fail | MIL ON with KOER |
Communication Protocols and Your Auto Drive OBDII EOBD Code Reader
Communication failures, detectable with an auto drive obdii eobd code reader, can arise from various issues: a damaged OBD connector, aftermarket stereo, or invalid vehicle data.
| Vehicle | Test Type | Standard |
|---|---|---|
| All OBDII | BAR-97 | Communicates with BAR-97 |
| All OBDII | OIS | Communicates with OIS and transmits required data1 |
1 Typically data from Mode $01 PID $00 (supported data) and Mode $01 PID $01 (MIL status, DTCs, monitor status).
Permanent Diagnostic Trouble Codes (PDTCs) and the Auto Drive OBDII EOBD Code Reader
Since July 1, 2019, the BAR-OIS Smog Check includes a PDTC check. Your auto drive obdii eobd code reader can retrieve these codes, which are similar to regular DTCs but are not erased by clearing DTCs or disconnecting the battery. The OBDII system clears PDTCs only after verifying the resolved issue.
| Model Year | Test Type | Standard |
|---|---|---|
| 1996-1999 | BAR-97 | Not Applicable |
| 2000-2009 | OIS | Not Applicable |
| 2010 and newer1 | OIS | Fail if PDTC present2,3,4,5 |
1 Some 2010 vehicles lack PDTC support.
2 PDTC failure occurs regardless of MIL status.
3 PDTCs are ignored after 15 warm-up cycles and 200 miles driven since last OBD information clearing (Mode $01 PID $30 and $31).
4 Known problematic vehicles are addressed by manufacturers; their codes are ignored by BAR-OIS.
5 Manufacturers offer extended warranties or recalls for some vehicles with PDTC clearing issues.
Modified Software Detection with an Auto Drive OBDII EOBD Code Reader
As of July 19, 2021, a modified software check was implemented. Software with a CARB Executive Order should not trigger a failure. Vehicles with illegally modified software, detectable by an auto drive obdii eobd code reader, will fail. The Vehicle Inspection Report will indicate “Modified Software.” Retesting is permitted after restoring OEM-approved or CARB-approved software.
Conclusion: Leveraging Your Auto Drive OBDII EOBD Code Reader
Understanding OBD standards and utilizing an auto drive obdii eobd code reader are essential for successful Smog Check inspections. This guide provides a framework for diagnosing and addressing common OBD issues, ensuring vehicles meet emission requirements. Always consult manufacturer resources for specific vehicle information and recall status.
