GM Service Manual Online
For 1990-2009 cars only

Service of the engine control module (ECM) should 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 replacement ECM should be checked to ensure that the correct part is being used. If the correct part is being used, remove the faulty ECM and install the new service ECM.

Notice: 

   • 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.

Important: Before removing the engine control module (ECM), use the scan tool to capture the ECM data. This captured data will then need to be restored into the NEW ECM. Refer to Control Module References .

Removal Procedure

  1. Using a scan tool, capture the ECM data.
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  3. Remove the washer solvent container. Refer to Windshield Washer Solvent Container Replacement .

  4. Object Number: 1655955  Size: SH
  5. Disconnect the ECM electrical connectors.

  6. Object Number: 1655954  Size: SH
  7. Release the ECM upper retaining tabs.
  8. Remove the ECM from the bracket.

Installation Procedure


    Object Number: 1655954  Size: SH
  1. Place the bottom edge of the ECM into the bracket lower retainers.
  2. Push the ECM towards the bracket until the upper edge of the ECM snaps into place.

  3. Object Number: 1655955  Size: SH
  4. Connect the ECM electrical connectors.
  5. Install the washer solvent container. Refer to Windshield Washer Solvent Container Replacement .
  6. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  7. If a NEW ECM was installed, program the ECM. Refer to Control Module References .
  8. Perform the turbocharger learn procedure. Refer to Turbocharger Learn .