GM Service Manual Online
For 1990-2009 cars only

Service of the PCM should normally consist of either replacement of the PCM or 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%. 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. Turn OFF the ignition.
  3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  4. Disconnect the IAT sensor electrical connector.
  5. Carefully remove the air intake duct from the throttle body and air cleaner housing (1).

  6. Object Number: 481272  Size: SH
  7. Remove the two screws (2) from the two air cleaner housing sections.
  8. Remove the air cleaner housing cover assembly.

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

Installation Procedure


    Object Number: 481275  Size: SH
  1. Reconnect the PCM connectors.
  2. Tighten
    Tighten the PCM harness connector screws (1) to 8 N·m or 71 lb. in.


    Object Number: 481272  Size: SH
  3. Carefully reinstall the PCM and harness into the PCM housing (3).
  4. Reinstall the air cleaner housing cover assembly (1).
  5. Reinstall the two air cleaner assembly screws (2) from the two air cleaner housing sections.
  6. Tighten
    Tighten the two air cleaner assembly screws to 4 N·m or 35 lb. in.

  7. Carefully reinstall the air intake duct to the throttle body and air cleaner housing.
  8. Reconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in engine electrical.
  9. If a new PCM is being installed, program the EEPROM.
  10. The Replacement PCM will NOT allow Secondary AIR Pump operation until a total of 10 miles have been accumulated.

EEPROM Programming

  1. Set-up - Ensure that the following conditions have been met:
  2. • The battery is fully charged.
    • The ignition is ON.
    • The Techline Equipment cable connection at the DLC is secure.
  3. Program the PCM using the latest software matching the vehicle. Refer to up-to-date Techline equipment user's instructions.
  4. If the PCM fails to program, proceed as follows:
  5. • Ensure that all PCM connections are OK.
    • Check the Techline equipment for the latest software version.
    • Attempt to program the PCM. If the PCM still cannot be programmed properly, replace the PCM. You must program the replacement PCM.
    • Perform the Crankshaft Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn

Functional Check

  1. Perform the On-Board Diagnostic System Check. Refer to Powertrain On Board Diagnostic (OBD) System Check .
  2. Start the engine and let the engine run for one minute.
  3. Use the scan tool in order to scan for DTCs.