C 1500 Yukon 2WD V8-5.3L VIN Z Flex Fuel (2003)
Engine Control Module: Service and Repair
Repair Instructions
POWERTRAIN CONTROL MODULE (PCM) REPLACEMENT
Service of the powertrain control module (PCM) should consist of either replacement of the PCM or programming of the electrically erasable
programmable read only memory (EEPROM). If the diagnostic procedures call for the PCM to be replaced, the replacement PCM should be checked to
ensure that the correct part is being used. If the correct part is being used, remove the faulty PCM and install the new service PCM.
IMPORTANT:To prevent internal PCM damage, the ignition switch must be OFF when disconnecting or reconnecting power to the PCM.
Remove any debris from around the PCM connector surfaces before servicing the PCM. Inspect the PCM module connector gaskets
when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into
the PCM.
The replacement PCM must be programmed.
Removal Procedure
1. Disconnect the negative battery cable.
2. Release the PCM cover mounting tabs.
3. Release the PCM cover from the mounting brackets.
4. Remove the PCM cover.
5. Loosen the PCM electrical connector bolts (2).
NOTE: Refer to PCM and ESD Notice in Service Precautions See: Service Precautions.
6. Disconnect the PCM electrical connectors.