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.
- Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
- 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.
- Disconnect the ECM electrical connectors (2).
- Release the ECM cover retaining tabs.
- Remove the ECM cover from the bracket.
- Remove the ECM cover.
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.