LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2001 >> Aztek Base, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 943 (Engine Controls - 6.6L (Lb7) (Introduction)) >> Repair Instructions >> Engine Control Module (ECM) Replacement >> Removal Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Removal Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
  • To prevent internal ECM damage, the ignition switch must be OFF when disconnecting or connecting power to the ECM.
  • Remove any debris from the ECM connector surfaces before servicing the ECM. Inspect the ECM module connector gaskets when diagnosing or replacing the ECM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the ECM.
  • The replacement ECM must programmed.
    IMPORTANT: 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%. 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.
  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 Disconnect/Connect Procedure (Single Battery) or Battery Negative Cable Disconnect/Connect Procedure (Auxiliary Battery) in Engine Electrical.
  3. If equipped with the Allison transmission regular production option (RPO) M74, remove the engine harness clip from the ECM cover.
    4. Fig 1: Engine Harness Clip At ECM Cover
    GM877692Courtesy of GENERAL MOTORS CORP.
  4. Release the ECM cover mounting tabs.
  5. Release the ECM cover from the mounting bracket.
  6. Remove the ECM cover.
    7. Fig 2: View Of ECM Cover & Mounting Bracket
    GM814118Courtesy of GENERAL MOTORS CORP.
  7. Loosen the ECM electrical connector bolts (2).
  8. Disconnect the ECM electrical connectors (3).
    9. Fig 3: View Of ECM Electrical Connector & Bolts
    GM877694Courtesy of GENERAL MOTORS CORP.
  9. Release the spring latch from the ECM.
  10. Release the ECM mounting tabs from the ECM.
  11. Remove the ECM.
    12. Fig 4: ECM & Mounting Tabs
    GM877695Courtesy of GENERAL MOTORS CORP.
scientia non olet · About LEMON Manuals