- Powertrain/On-Board Diagnostic System Check

Self Diagnostic System Check:

NOTE: For referrals to any chart not included in DIAGNOSTIC CHARTS, refer to COMPUTERIZED ENGINE CONTROLS.


The SELF-DIAGNOSTIC CIRCUIT CHECK is an organized approach for identifying a problem caused by the on-car computer-controlled electronics. Understanding this chart and using it correctly will reduce diagnosis time and prevent the unnecessary replacement of parts. Refer to HOW TO ENTER DIAGNOSTIC MODE.

NOTES ON CHART:

1. A two second bulb check of the "SERVICE AIR CONDITIONING" lamp at key "ON" (and after crank) confirms battery, ignition, and ground integrity to the BCM.

2. Verifies proper operation of the "COOLANT TEMP" and "SERVICE ENGINE SOON" lamps.

3. A two second bulb check of the "Service Engine Soon" lamp confirms battery, ignition, and ground integrity to the PCM/ECM.

4. The Electronic Climate Control panel (ECC) and Fuel Data Center (FDC) must be functional in order to use the SELF-DIAGNOSTIC CIRCUIT CHECK. Check if the panels illuminate and respond when the buttons are depressed.

5. After entering diagnostics, refer to HOW TO ENTER DIAGNOSTICS, record all displayed trouble codes and note those displayed during both the first and second pass. Codes displayed during the first pass only are history, (INTERMITTENTS) may require a visual or physical inspection of circuitry to isolate. Codes displayed during the second pass are current, (hard) malfunctions which can be diagnosed using the appropriate trouble code charts. If no codes were stored refer to DIAGNOSIS BY SYMPTOM.


HOW TO CLEAR TROUBLE CODES

Diagnostic Mode:

Trouble codes stored in the PCM/ECM's memory may be cleared (erased) by entering the diagnostic mode and then depressing the "OFF" and "HI" buttons on the Climate Control Panel (CCP) simultaneously. Hold until "E.O.O" appears. Trouble codes stored in the BCM's memory may be cleared by depressing the "OFF" and "LO" buttons simultaneously until "F.O.0" appears. After "E.O.0" or "F.O.0" is displayed ".7.0" will appear. With .7.0 displayed turn the ignition off for at least 10 seconds before reentering the diagnostic mode.

NOTE: If PCM/ECM codes are cleared at any time, code snapshot information will be lost. To return to .7.0 without losing code snapshot information, clear BCM codes by depressing the "OFF" and "LO" buttons simultaneously.