Diagnostic Procedure
- Connect scan tool to DLC. DLC is located on lower left side of instrument panel, near steering column. If scan tool powers up, go to next step. If scan tool does not power up, diagnose scan tool concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Turn ignition switch to RUN position. Attempt to establish communication with BCM and PCM. If scan tool communicates with BCM and PCM, go to next step. If scan tool does not communicate with BCM and PCM, diagnose body control system. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Using scan tool, retrieve all DTCs from BCM and PCM. If any DTC is retrieved, go to next step. If no DTCs are retrieved, repair shift interlock concern by symptom. See SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
- If "U" series DTCs (communication DTCs) are not retrieved, go to next step. If "U" series DTCs are retrieved, diagnose body control system. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- If DTCs B1000 or B1001 are not retrieved, go to next step. If DTCs B1000 or B1001 are retrieved, diagnose body control system. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- If DTC B1328 is retrieved, diagnose charging system. See appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS. If DTC B1328 is not retrieved, diagnose indicated DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If indicated DTCs are not included within this article, see appropriate article related to DTC for diagnosis (i.e., ACCESSORIES & EQUIPMENT, ENGINE PERFORMANCE, etc.).
NOTE:
During any diagnostic procedure, it must be determined if DTCs are hard failure or intermittent failure. Diagnostic tests will not usually help analyze intermittent failures. For additional information, see HARD OR INTERMITTENT DTC DETERMINATION