Engine Control Module: Service and Repair

PCM Location:

Powertrain Control Module (PCM):

Service of the PCM should normally consist of either replacement of the PCM or a MEM-CAL change. If the diagnostic procedures call for the PCM to be replaced, the Memory-Calibration unit (MEM-CAL) and PCM should be checked first to see if they are the correct parts. A computer controlled device shorted to ground or voltage can possible cause repeat failure of the PCM.

When replacing a production PCM with a service PCM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and the MEM-CAL must be removed from the PCM being replaced and transferred to the new unit.


CAUTION: The ignition switch should always be "OFF" when installing or removing a PCM connector.



REMOVE OR DISCONNECT

1. Right hand hush panel.
2. Connectors to PCM.
3. PCM retaining screws.
4. Pull PCM down.
5. Bracket, top and front mounting pins from PCM (if replacing PCM).
6. MEM-CAL cover and MEM-CAL.

INSTALL OR CONNECT

1. Old MEM-CAL in new PCM.
2. Bracket and mounting pins to new PCM.
3. PCM.
4. PCM retaining screws.
5. PCM connectors.
6. Hush panel.
7. Turn ignition "ON".
8. Enter diagnostics. Refer to COMPUTERS AND CONTROL SYSTEMS / DIAGNOSIS, TESTING AND INSPECTION PROCEDURES / ON-BOARD DIAGNOSTIC PROCEDURES.
^ Code E052 should appear.
^ If the diagnostic message "NO PCM DATA" appears on the Climate Control Center (CCC) display, the MEM-CAL may be defective or not fully seated.
9. Perform TPS/Idle learn procedure. Refer to FUEL SUPPLY AND AIR INDUCTION / ADJUSTMENT PROCEDURES / TPS-IDLE LEARN PROCEDURES.

NOTE: Failure to perform the TPS/Idle learn procedure may result in severe driveablity problems.