GM Service Manual Online
For 1990-2009 cars only

Notice: In order to prevent possible Electrostatic Discharge damage to the PCM, Do Not touch the connector pins or the soldered components on the circuit board.

Service of the PCM should normally consist of either replacement of the PCM or EEPROM programming. If the diagnostic procedures call for the PCM to be replaced, PCM should be checked first to see if it is the correct part. If it is, remove the faulty PCM and install the new service PCM.

Notice: Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.

Important:  When replacing the production PCM with a service PCM, it is important to transfer the broadcast code and production PCM number to the service PCM label. Do not record on PCM cover. This will allow positive identification of PCM parts throughout the service life of the vehicle.

THE SERVICE PCM EEPROM WILL NOT BE PROGRAMMED. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.

Removal Procedure

    Important: It is necessary to record the remaining engine oil life. If the replacement module is not programed with the remaining engine oil life, the engine oil life will default to 100%. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5000 km (3,000 mi) from the last engine oil change.

  1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in engine electrical.
  3. Remove the PCM access cover.
  4. Disconnect the connectors from PCM.
  5. Remove the PCM from engine compartment.

Installation Procedure

  1. Install the PCM.
  2. Connect the connectors to the PCM.
  3. Reinstall the access cover on the PCM housing.
  4. Reconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in engine electrical.

If a new PCM is being installed, program the EEPROM.

EEPROM Programming

  1. Set-up - Ensure that the following conditions have been met:
  2. •  The ignition is on.
    •  The Techline equipment connection at the Data Link Connector (DLC) is secure.
  3. If the PCM fails to program, check the Techline equipment for the latest software version.
  4. Attempt to program the PCM. If the PCM still cannot be programmed properly, replace the PCM. The replacement PCM must be programmed.

Functional Check

  1. Perform On-Board Diagnostic System Check.
  2. Start engine and run for one minute.
  3. Scan for DTCs using the scan tool.