HARD FAILURES
All vehicles are equipped with a permanent fault memory. If a fault occurs in monitored sensors and components, they store a hard fault in memory.
Hard failures of monitored sensors and/or components cause Malfunction Indicator Light (MIL) to come on and remain on until problem is repaired. If MIL (CHECK ENGINE light) comes on and remains on during vehicle operation, cause of malfunction must be determined.
If malfunctions are present for more than 5 seconds, they are stored as Diagnostic Trouble Codes (DTCs) and will be displayed as a permanent malfunction even if malfunction is not present during DTCs display. Malfunctions affecting oxygen sensor control can only be read accurately after a test drive of at least 10 minutes.
INTERMITTENT FAILURES
If a malfunction occurs for no more than 5 seconds, they are stored and considered to be "sporadic" (intermittent failures). When displayed on scan tester, malfunctions will have "SP" (sporadic) code.
RETRIEVING CODES
Note. See ENTERING SELF-DIAGNOSTICS for additional scan tester operating instructions.
- Turn ignition on. Locate Adapter Cable (357 971 514E) in glove box. Connect adapter cable to Data Link Connectors (DLC), located on center instrument panel, behind panel adjacent to ashtray. (Scheme 7) Connect Black end of adapter cable to Black DLC and White end of cable to White DLC.
- Leave adapter cable attached for 5 seconds, until on-board diagnostic MIL (CHECK ENGINE light) begins to blink. Remove adapter cable. Allow on-board diagnostic code retrieval procedure to run until Code 4444 (no faults indicated) or Code 0000 (end of output) appears. To end code retrieval procedure, reconnect adapter cable to DLCs or turn ignition off.
- To erase fault codes, turn ignition off. Connect adapter cable and turn ignition on. Leave adapter cable attached for 5 seconds, until CHECK ENGINE light begins to blink.
- When light displays code 4444 (no faults indicated), reconnect adapter cable to DLCs or turn ignition off to end code clearing procedure. Fault memory is now erased.
Scheme 7
CLEARING CODES
See RETRIEVING CODES .
SUMMARY
If no hard fault codes (only "sporadic" codes) are present, driveability symptoms exist or intermittent codes exist, proceed to the H - TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.