Diagnostic System Check
WARNING: This page is about a different car, the 2003 Saturn Vue and 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
After performing a visual and physical underhood inspection, the diagnostic system check is the starting point for all diagnostic procedures or finding the cause of an emissions test failure.
The correct procedure to diagnose a problem is to follow three basic steps:
- Are the on-vehicle diagnostics working? If not, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. This is determined by performing the diagnostic system check. Since this is the starting point for the diagnostic procedures or finding the cause of an emissions test failure, always begin here. Go to next step.
- Is there a DTC stored? If a DTC is stored, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . This will determine if the fault is still present. If no DTC is stored, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
NOTE:
Scan serial data transmitted by the TCM. This involves reading the information available on the serial data stream with one of the scan tools available for that purpose.