GM Service Manual Online
For 1990-2009 cars only

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: It is necessary to record the remaining engine oil life. If the replacement engine control module (ECM) is not programed with the remaining engine oil life, the engine oil life will default to 100 percent. If the replacement ECM 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 oil change.

Important: It is necessary to record the remaining automatic transaxle fluid life. If the replacement ECM is not programed with the remaining transaxle fluid life, the transaxle fluid life will default to 100 percent. If the replacement ECM is not programmed with the remaining transaxle fluid life, the transaxle fluid will need to be changed at 83 000 km (50,000 mi) from the last transaxle fluid change.

Removal Procedure


    Object Number: 1670786  Size: SH
  1. Using a scan tool, retrieve the percentage of remaining engine oil and automatic transaxle fluid life. Record the remaining engine oil and transaxle fluid life.
  2. Ensure that the ignition is in the OFF position.
  3. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  4. Disconnect the engine harness electrical connector from the mass air flow/intake air temperature (MAF/IAT) sensor.

  5. Object Number: 1661022  Size: SH
  6. Disconnect the positive crankcase ventilation (PCV) fresh air tube quick connect fitting from the air duct. Refer to Plastic Collar Quick Connect Fitting Service.

  7. Object Number: 1665331  Size: SH
  8. Disconnect the secondary air injection (AIR) pump inlet tube quick connect fitting from the air cleaner upper housing. Refer to Plastic Collar Quick Connect Fitting Service.

  9. Object Number: 1670790  Size: SH
  10. Loosen the air cleaner outlet duct clamp at the throttle body.
  11. Remove the air cleaner outlet duct from the throttle body.

  12. Object Number: 1670787  Size: SH
  13. Disengage the lower housing clips (1).
  14. Disengage the upper housing front tabs from the lower housing.
  15. Remove the air cleaner upper housing.

  16. Object Number: 1664479  Size: SH
  17. Disengage the engine harness electrical connector lever locks at the ECM.
  18. Remove the engine harness electrical connectors from the ECM.
  19. Remove the ECM from the air cleaner lower housing.

Installation Procedure

Important: Inspect the following areas prior to installing the ECM:

   • No debris in the air filter/ECM housing assembly, or the MAF/IAT sensor inlet screen that may distort the air flow.
   • No signs of damage to the air filter/ECM housing assembly, or the intake air duct. If a problem is found, replace the components as necessary.


    Object Number: 1664479  Size: SH
  1. Install the ECM to the lower air cleaner housing.
  2. Install the engine harness electrical connectors to the ECM.
  3. Engage the engine harness electrical connector lever locks at the ECM.

  4. Object Number: 1670787  Size: SH
  5. Install the air cleaner upper housing.
  6. Engage the upper housing front tabs to the lower housing.
  7. Engage the lower housing clips (1).

  8. Object Number: 1670790  Size: SH

    Important: Properly install the air cleaner outlet duct to the throttle body. An improperly installed, distorted, or damaged air duct may cause a DTC to set.

  9. Install the air cleaner outlet duct to the throttle body.
  10. Notice: Refer to Fastener Notice in the Preface section.

  11. Tighten the air cleaner outlet duct clamp at the throttle body.
  12. Tighten
    Tighten the clamp to 3 N·m (27 lb in).


    Object Number: 1665331  Size: SH
  13. Connect the AIR pump inlet tube quick connect fitting to the air cleaner upper housing. Refer to Plastic Collar Quick Connect Fitting Service.

  14. Object Number: 1661022  Size: SH
  15. Connect the PCV fresh air tube quick connect fitting to the air duct. Refer to Plastic Collar Quick Connect Fitting Service.

  16. Object Number: 1670786  Size: SH
  17. Connect the engine harness electrical connector to the MAF/IAT sensor.
  18. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  19. Program the ECM. Refer to Control Module References.