GM Service Manual Online
For 1990-2009 cars only

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 PCM replacement, check the PCM first to see if the PCM is the correct part. If the PCM is faulty, remove the module and install the new service PCM.

The new service PCM will not be programmed. You must program the new PCM. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.

Notice: Do not touch the connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage to the 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.

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 percent. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5 000 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. Turn OFF the ignition.
  3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  4. Remove the intake duct. Refer to Air Cleaner Inlet Duct Replacement .

  5. Object Number: 481272  Size: SH
  6. Remove the 2 screws (2) from the upper and lower air cleaner assembly sections.
  7. Remove the upper air cleaner housing assembly (1).

  8. Object Number: 481275  Size: SH
  9. Without disconnecting the PCM connectors (1), remove the PCM (3) and harness from the PCM housing (2).
  10. Disconnect the PCM connectors (1).

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

  1. Reconnect the PCM connectors (1).
  2. Tighten
    Tighten the connectors to 8 N·m (71 lb in).


    Object Number: 481275  Size: SH
  3. Carefully reinstall the PCM (3) and harness into the PCM housing (2).

  4. Object Number: 481272  Size: SH
  5. Install the upper air cleaner housing assembly (1).
  6. Install the 2 screws (2) into the upper and lower air cleaner assembly sections.
  7. Tighten
    Tighten the screws to 4 N·m (35 lb in).

  8. Install the intake duct. Refer to Air Cleaner Inlet Duct Replacement .
  9. Reconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  10. The Replacement PCM will NOT allow secondary AIR pump operation until a total of 10 miles have been accumulated.
  11. The new PCM must be programmed. Refer to Control Module References for programming and setup information.