Preliminary Checks: Notes

WARNING: This page is about a different car, the 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

Before performing Symptom based diagnosis you must perform the DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS (ALTERNATIVE FUELS) under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 2.2L CAVALIER - BI-FUEL - CNG/GASOLINE article. The System Check will determine the following:

PCM and the MIL are operating correctly.
There are no DTCs stored.
Scan tool data is within normal operating range.

Several of the Symptom diagnostic procedures require that a visual and physical check be performed. Always perform a visual and physical check before using a symptom diagnostic procedure.

After all checks have been performed, verify customer complaint and locate correct symptom. Check items indicated under that symptom. Not all items listed under each symptom apply to all models and systems. These procedures will normally recommend testing of a specific system or component, such as EGR, ignition, TCC, etc. See SYSTEM & COMPONENT TESTING - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article for test procedures.