Diagnostic Trouble Codes: Notes

NOTE: In following diagnostic tests, schematics are courtesy of General Motors Corp.

NOTE: Before clearing DTCs, perform On-Board Diagnostic (OBD) system check. See appropriate BASIC TESTING article. Record FREEZE FRAME and FAILURE RECORDS for reference during testing. Data will be erased when DTCs are cleared.

NOTE: If VCM/PCM is replaced, NEW VCM/PCM must be programmed using special manufacturer's equipment.