Diagnostic Procedure

The procedures contained in this article include specifications, instructions and graphics needed to diagnose PCM powertrain system. The diagnostics are based on the failure condition or symptom being present at the time of diagnosis. Use the following recommendations:

• First make sure the DRBIII® is communicating with the appropriate modules; i.e., if the DRBIII® displays a No Response condition, you must diagnose the condition first before proceeding. See appropriate BASIC DIAGNOSTIC PROCEDURES article (no response with a no-start condition) or appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT (all other no response conditions).
• Using DRBIII® scan tool read Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• If no DTCs are present, identify the customer complaint and diagnose by symptom. See appropriate TROUBLE SHOOTING - NO CODES article.
• If any DTCs are present, perform the appropriate diagnostic test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .