GM Service Manual Online
For 1990-2009 cars only

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 5 000 km (3,000 mi) from the last engine oil change.
   • It is necessary to record the remaining automatic transmission fluid life. If the replacement module is not programed with the remaining automatic transmission fluid life, the automatic transmission fluid life will default to 100 percent. If the replacement module is not programmed with the remaining automatic transmission fluid life, the automatic transmission fluid will need to be changed at 83 000 km (50,000 mi) from the last automatic transmission fluid change.

Removal Procedure


    Object Number: 1888714  Size: SH
  1. Using a scan tool, retrieve the percentage of remaining engine oil and the remaining automatic transmission fluid life. Record the remaining engine oil and the remaining automatic transmission fluid life.
  2. Release the electronic control module (ECM) bracket (1) from the battery cover (2).

  3. Object Number: 1888715  Size: SH
  4. Release the retaining tabs on the ECM bracket and slide the ECM out of it.
  5. Disconnect the engine wiring harness electrical connectors (1) from the ECM (5).

Installation Procedure


    Object Number: 1888715  Size: SH
  1. Connect the engine wiring harness electrical connectors (1) to the ECM (5).
  2. Slide the ECM into the ECM bracket until it locks into place.

  3. Object Number: 1888714  Size: SH
  4. Install the ECM bracket (1) onto the air cleaner assembly cover (2) until it locks in place.
  5. If replacing the ECM, program the ECM. Refer to Control Module References.