GM Service Manual Online
For 1990-2009 cars only

Vehicle Control Module (VCM)

The service of the VCM consists of replacing the VCM. If the diagnostics call for replacement of the VCM, transfer the KS Calibration PROM and program the EEPROM in the VCM. Refer to EEPROM Programming .

KS Calibration PROM

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

Important: In order to prevent the internal VCM damage, the ignition must be OFF when disconnecting or reconnecting the power to the VCM (battery cable, ECM fuse, jumper cables, etc.).

Removal Procedure

  1. Disconnect the negative battery cable.
  2. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.


    Object Number: 25251  Size: SH
  3. Remove the connectors from the VCM.
  4. Remove the mounting hardware.
  5. Remove the VCM from the engine compartment.


    Object Number: 2315  Size: SH
  6. Remove the VCM access cover.
  7. Important: The replacement VCM is supplied without a KS Calibration PROM so for reuse in the new VCM carefully remove the PROM from the defective VCM.


    Object Number: 10783  Size: SH
  8. Remove the Calibration PROM.
  9. • Using the thumb and first finger, remove the KS Calibration PROM by gently squeezing each end of the blue KS Calibration PROM
    • Pull upward.
    • Do not remove the cover of the KS Calibration PROM. Use of an unapproved KS Calibration PROM removal methods may cause damage to the KS Calibration PROM or the socket.

    Object Number: 10930  Size: SH
  10. Inspect for the alignment notches of the KS Calibration PROM.
  11. Carefully set it aside.
  12. Do not open the KS Calibration PROM.

  13. Object Number: 2315  Size: SH
  14. Remove the new VCM from the packaging.
  15. Check the service number in order to make sure it is the same as the defective VCM.

  16. Remove the access cover.

Installation Procedure


    Object Number: 10783  Size: SH

    Important: Press only on the ends of the KS Calibration PROM. The small notches in the KS Calibration PROM must align with the small notches in the KS Calibration PROM socket. Gently press on the KS Calibration PROM until it is firmly seated in the socket. Listen for the click.

  1. Install the KS Calibration PROM in the KS Calibration PROM socket.

  2. Object Number: 2315  Size: SH
  3. Install the access cover on the VCM.
  4. Install the VCM in the engine compartment.

  5. Object Number: 25251  Size: SH
  6. Install the connectors to the VCM.
  7. The MIL, antilock and brake lamps will continue to be enabled until the VCM is programmed. Once the programming is complete, the lamps will turn off and normal operation will occur.
  8. Connect the negative battery cable.
  9. Notice: The ignition should always be OFF when installing or removing the VCM connectors in order to prevent damage.

  10. Program the EEPROM. Refer to EEPROM Programming .