Diagnostic Aids

WARNING: This page is about a different car, the 2001 GMC Sonoma and 2001 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Extreme high or low ambient temperatures may prevent EVAP system tests from initiating. Performing a visual inspection prior to running EVAP service bay test may prevent having to repeat the test. A loose fuel cap may cause a service bay test to abort or fail and prevent the I/M System Status from updating. A failed or aborted test will require vehicle to cool down in order to meet the enable criteria to run another test.

The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the emission related DTC portion of I/M System Status display will indicate that MIL is requested. The I/M System Status also registers the number of DTCs.