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Engine Control Module: Service and Repair

Powertrain Control Module (PCM)

Powertrain Control Module (PCM) Replacement:




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. Also, perform the 'PCM Replacement Check' chart in this section before replacing a PCM to assure that the replacement PCM will not be damaged. The PROM can easily be checked using parameter P.2.5. If the part numbers are correct, remove the MEM-CAL from the faulty PCM and install them in the new service PCM. THE SERVICE PCM WILL NOT CONTAIN A MEM-CAL, so care should be taken when removing the MEM-CAL from a defective PCM which is being replaced. Trouble Code F32 (No PCM Data) indicates the MEM-CAL is installed improperly or has malfunctioned. If Code F32 is current, check to see if the MEM - CAL is fully seated. If not fully seated, press firmly on the ends of the MEM - CAL and make sure the retaining clips have locked. If the MEM-CAL is installed correctly and Code 'F32' still shows, diagnose using the code chart for F32. After replacement of an PCM, clear stored codes, and check the vehicle for proper operation.

NOTICE: To prevent internal PCM damage, the ignition must be 'OFF' when disconnecting or reconnecting power to PCM (for example, battery positive cable, PCM connectors, PCM fuse, jumper cables, etc.).

Remove or Disconnect

1. Right hand hush panel.
2. Connectors to PCM.
3. PCM retaining nut.
4. Move PCM rearward to disengage the front mounting pin.
5. Pull PCM down.
6. Bracket, and front mounting pin.
7. MEM-CAL cover and MEM-CAL.

Install or Connect

1. Old MEM-CAL in new PCM.
2. Bracket and mounting pin to new PCM.
3. PCM.
4. PCM retaining nut.
5. PCM Connectors.
6. Hush panel.
7. Turn ignition 'ON'.
8. Enter diagnostics.
A. Code E052 should appear.
B. If the diagnostic message 'NO PCM DATA' appears on the display, the MEM-CAL may be defective or not fully seated.
- If it is not fully seated, press firmly on the ends of the MEM - CAL and make sure the retaining clips have locked.
- If it is necessary to remove the MEM -CAL, follow the appropriate procedures.
9. Perform TPS/Idle Learn Procedure.

Important
- Failure to perform the TPS/Idle Learn Procedure may result in severe driveability problems.
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