Blazer 2WD V6-4.3L VIN X (2004)
Engine Control Module: Service and Repair
POWERTRAIN CONTROL MODULE (PCM) REPLACEMENT
Service of the powertrain control module (PCM) should normally consist of either replacement of the powertrain control module (PCM) or electrically
erasable programmable read only memory (EEPROM) programming. If the diagnostic procedures call for the PCM to be replaced, the PCM should be
inspected first to see if the correct part is being used.
NOTE: Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery
cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.
IMPORTANT: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM module connector gaskets when
diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminant intrusion into the PCM.
Removal Procedure
CAUTION: Refer to Battery Disconnect Caution in Service Precautions.
NOTE: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.
1. Disconnect the negative battery cable.
2. Move the PCM retention bar and retainer away from the PCM.
