GM Service Manual Online
For 1990-2009 cars only

System Status For Satisfying the Federal Inspection/Maintenance (I/M) Regulations

The scan tool System Info menu includes the System Status selection.

Several states require that the vehicle pass on-board (OBD ll system) tests for the major diagnostics prior to having a vehicle I/M emission inspection. Some areas may require that the vehicle pass the OBD II system tests and the I/M emission inspection in order to renew license plates.

Using a scan tool, the technician can observe the System Status (Complete or Not Complete) in order to verify that the vehicle meets the criteria which complies with the local area requirements. Use the System Status display in order to monitor any of the following systems or a combination of the systems (depending on the vehicle make and model) for I/M readiness:

    • The catalyst
    • The heated oxygen sensor (HO2S)
    • The heated oxygen sensor (HO2S) heater
    • The exhaust gas recirculation (EGR) system
    • The evaporative emissions (EVAP) system
    • The secondary air injection system (AIR)

Important: The System Status display indicates only if the PCM has completed the required tests (DTCs). The System Status display does not necessarily mean that the test has passed. If a failure indication is present for a DTC associated with one of the above systems, that test has failed. Diagnosis and repair are necessary in order to meet the I/M requirement. Verify that the vehicle passes all of the diagnostic tests associated with the displayed System Status prior to returning the vehicle to the customer.

Following a DTC Info Clear, a battery disconnect, or a control module replacement, all of the System Status information is set to Not Complete.

Refer to the diagnostic support information associated with each DTC in order to obtain the Conditions for Running the DTC. The vehicle operating conditions that the system must meet in order for a DTC to run are the Conditions for Running the DTC.

The System Status table shows the DTCs that must run in order for the System Status to indicate a system test has been Completed.

System Status

System Status

DTCs Used to Set System Status

Catalyst

P0420

HO2S

P0133, P1133 and P1134

HO2S Heater

P0135 and P0137

EGR System

P0401

EVAP System

P0440, P0442, P0446, P1441, or the Service Bay Test

AIR System

P0410, P0412, P0418