GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Service of the engine control module (ECM) should normally consist of either replacement of the ECM or programming of the electrically erasable programmable read only memory (EEPROM). If the diagnostic procedures call for the ECM to be replaced, the ECM should be inspected first to see if the correct part is being used. If the correct part is being used, remove the faulty ECM and install the new service ECM. The replacement ECM must be programmed.

Caution: 

   • Turn the ignition OFF when installing or removing the control module connectors and disconnecting or reconnecting the power to the control module (battery cable, powertrain control module (PCM)/engine control module (ECM)/transaxle control module (TCM) pigtail, control module fuse, jumper cables, etc.) in order to prevent internal control module damage.
   • Control module damage may result when the metal case contacts battery voltage. DO NOT contact the control module metal case with battery voltage when servicing a control module, using battery booster cables, or when charging the vehicle battery.
   • In order to prevent any possible electrostatic discharge damage to the control module, do no touch the connector pins or the soldered components on the circuit board.
   • Remove any debris from around the control module connector surfaces before servicing the control module. Inspect the control module connector gaskets when diagnosing or replacing the control module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the control module.
   • The replacement control module must be programmed.

Note: 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 5000 km (3,000 mi) from the last engine oil change.


    Object Number: 1922190  Size: SH
  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.
  3. Disconnect the engine wiring harness electrical connectors (1) from the ECM.

  4. Object Number: 1922570  Size: SH
  5. If removing the ECM and bracket assembly in order to access other components perform the following steps, otherwise proceed to step 5.
  6. 4.1. Remove the ECM bracket nuts (1) and bolts (2).
    4.2. Remove the ECM and bracket assembly (3) from the studs on the intake manifold.

    Object Number: 1922191  Size: SH
  7. Disengage the retainers (1) securing the ECM to the bracket.

  8. Object Number: 1922192  Size: SH
  9. Remove the ECM (1) from the bracket.

  10. Object Number: 1922197  Size: SH
  11. If the ECM bracket requires removal, perform the following steps:
  12. 7.1. Remove the ECM bracket bolts (2) and nuts (1).
    7.2. Remove the ECM bracket (3) from the studs on the intake manifold.

Installation Procedure


    Object Number: 1922197  Size: SH
  1. If the ECM and bracket assembly was removed in order to access other components, proceed to step 5.
  2. If the ECM bracket was removed, perform the following steps, otherwise proceed to step 3:
  3. 2.1. Install the ECM bracket (3) to the studs on the intake manifold.

    Caution: Refer to Fastener Caution in the Preface section.

    2.2. Install the ECM bracket bolts (2) and nuts (1) and tighten to 9 N·m (80 lb in).

    Object Number: 1922192  Size: SH
  4. Install the ECM (1) to the bracket.

  5. Object Number: 1922191  Size: SH
  6. Ensure that the retainers (1) completely engage and secure the ECM.

  7. Object Number: 1922570  Size: SH
  8. If the ECM and bracket assembly was removed in order to access other components, perform the following steps:
  9. 5.1. Install the ECM and bracket assembly (3) to the studs on the intake manifold.
    5.2. Install the ECM bracket bolts (2) and nuts (1) and tighten to 9 N·m (80 lb in).

    Object Number: 1922190  Size: SH
  10. Connect the engine wiring harness electrical connectors (1) to the ECM.
  11. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  12. If a NEW ECM was installed, program the ECM. Refer to Control Module References.
  13. Using a scan tool, set the remaining engine oil life.