Powertrain Control Module (PCM) Replacement

Service of the Powertrain Control Module (PCM) should normally consist of either replacement of the PCM or Electrically Erasable Programmable Read Only Memory (EEPROM) programming. If the diagnostic procedures call for the PCM to be replaced, the PCM should be inspected first to see if the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.

IMPORTANT:
^ To prevent internal PCM damage, the ignition must be OFF when disconnecting or reconnecting power to the PCM. For example, when working with a battery cable, PCM pigtail, PCM fuse, or jumper cables.
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM module connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
^ The replacement PCM will not be programmed. DTC P0601 and P0602 indicate the EEPROM is not programmed or has malfunctioned. The following MUST be performed anytime the PCM is replaced:
1. Programming of the EEPROM
2. The PCM Password Learn procedure - Refer to DTC P1631 Theft Deterrent Stan Enable Signal Not Correct.
3. The Idle Learn Procedure - Refer to Idle Learn Procedure.
4. The Crankshaft Position System Variation Learn Procedure - Refer to CKP System Variation Learn Procedure.
5. Resetting the engine oil life monitor - Refer to GM Oil Life System - Resetting.
6. The Functional Check

The following must be performed anytime the PCM is disconnected, loses power, or is reprogrammed:
1. The Idle Learn Procedure - Refer to Idle Learn Procedure.
2. The Functional Check




REMOVAL PROCEDURE

1. Release the PCM cover mounting holes (1.5) away from the mounting tabs on the PCM mounting bracket.
2. Release the PCM cover (8) from the mounting bracket.
3. Remove the PCM cover.

NOTE: Refer to PCM and ESD Notice in Cautions and Notices.

NOTE: Refer to Ignition and PCM Notice in Cautions and Notices.

4. Disconnect the PCM harness connectors (6).
5. Release the spring latch (2) from the PCM.
6. Release the PCM mounting tabs (3) from the PCM.
7. Remove the PCM (4) from the engine compartment.

INSTALLATION PROCEDURE

1. Install the PCM (4) to the PCM mounting bracket (7) ensuring that the mounting tabs (3) are engaged.
2. Secure the spring latch (2) to the PCM.

NOTE: Refer to Fastener Notice in Cautions and Notices.
3. Connect the PCM connectors (6) to the PCM (4).

Tighten
Tighten the PCM connector end fasteners to 8 N.m (70 lb in).

4. Install the PCM cover (8) to the PCM mounting bracket (7), ensuring the mounting tabs on the PCM mounting bracket are engaged into the mounting holes in the PCM cover.
5. If a new PCM is being installed, program the EEPROM. Programming and Relearning