C 3500 Truck 2WD V8-8.1L VIN G (2001)
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 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. If the correct part is being used, remove the faulty PCM and install the new service PCM.
IMPORTANT:
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To prevent internal PCM damage, the ignition must be OFF when disconnecting or reconnecting power to the PCM. For example, when working
with a battery cable, PCM pigtail, PCM fuse, or jumper cables.
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Remove any debris from 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.
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The replacement PCM will not be programmed. DTC P0601 and P0602 indicate the EEPROM is not programmed or has malfunctioned. The
following MUST be performed anytime the PCM is replaced:
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Programming of the EEPROM
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The PCM Password Learn procedure - Refer to Powertrain Control Module (PCM) Programming (On-Board) or Powertrain Control Module
(PCM) Programming (Off-Board).
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The Idle Learn Procedure
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The Crankshaft Position System Variation Learn Procedure - Refer to CKP System Variation Learn Procedure.
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Resetting the engine oil life monitor - Refer to GM Oil Life System - Resetting.
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The Functional Check
The following must be performed anytime the PCM is disconnected, loses power, or is reprogrammed:
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The Idle Learn Procedure - Refer to Idle Learn Procedure.
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The Functional Check
Removal Procedure
1. Release the PCM cover mounting holes (1,5) away from the mounting tabs on the PCM mounting bracket.
2. Release the PCM cover (8) from the mounting bracket.
3. Remove the PCM cover.
NOTE:
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Refer to PCM and ESD Notice in Service Precautions.
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Refer to Ignition and PCM Notice in Service Precautions.
4. Disconnect the PCM harness connectors (6).
