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: 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.

Important: 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.

Important: 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:

1. Programming of the EEPROM
2. The PCM Password Learn procedure -- Refer to DTC P1631 Theft Deterrent Start Enable Signal Not Correct .
3. The Idle Learn Procedure -- Refer to Idle Learn .
4. The Crankshaft Position System Variation Learn Procedure -- Refer to Crankshaft Position System Variation Learn .
5. The Functional Check

1. The Idle Learn Procedure -- Refer to Idle Learn .
2. The Functional Check

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. Release the PCM cover mounting holes (1,5) away from the mounting tabs on the PCM mounting bracket.
3. Release the PCM cover (8) from the mounting bracket.
4. Remove the PCM cover.

Notice: Do not touch the connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage to the PCM.

Notice: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.

5. Disconnect the PCM harness connectors (6).
6. Release the spring latch (2) from the PCM.
7. Release the PCM mounting tabs (3) from the PCM.
8. Remove the PCM (4) from the engine compartment.

1. Install the PCM (4) to the PCM mounting bracket (7) ensuring that the mounting tabs (3) are engaged.
2. Secure the spring latch (2) to the PCM.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Connect the PCM connectors (6) to the PCM (4).

Tighten
Tighten the PCM connector end fasteners to 8 N·m (70 lb in).

4. Install the PCM cover (8) to the PCM mounting bracket (7), ensuring the mounting tabs on the PCM mounting bracket are engaged into the mounting holes in the PCM cover.
5. If a new PCM is being installed, program the EEPROM.

1. Setup -- Ensure that the following conditions have been met:

•	The battery is fully charged.

•	The ignition is ON.

2. Program the PCM using the latest software matching the vehicle. Refer to the Techline terminal/equipment users instructions.
3. If the PCM fails to program, proceed as follows:

•	Ensure that all PCM connections are OK.

•	Inspect the Techline terminal or equipment for the latest software version.

•	Attempt to program the PCM. If the PCM still cannot be programmed properly, replace the PCM. The replacement PCM must be programmed.

4. Perform the PCM Password Learn procedure. Refer to DTC P1631 Theft Deterrent Start Enable Signal Not Correct .
5. Perform the Idle Learn Procedure. Refer to Idle Learn .
6. Perform the CKP System Variation Learn Procedure. Refer to Crankshaft Position System Variation Learn .
7. Reset the engine oil life monitor. Refer to GM Oil Life System Resetting .
8. Perform the Functional Check.

1. Clear the diagnostic trouble codes (DTCs).
2. Perform the Powertrain On-Board Diagnostic (OBD) System Check.
3. Start the engine and idle the engine for 1 minute.
4. Use the scan tool in order to inspect for DTCs.