Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2005 Buick LeSabre V6-3.8L VIN KFACTORY OEM SERVICE PROCEDURE
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 PCM replacement, check the PCM first to see if the PCM is the correct part. If the PCM is faulty, remove the module and install the new service PCM.
The new service PCM will not be programmed. You must program the new PCM. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.
NOTE:
- 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.
- 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.
Removal Procedure
1. Using a scan tool, retrieve the percentage of remaining engine oil. Record the remaining engine oil life.
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 percent. If the replacement module is not programmed with the remaining engine oil life, the engine oil will need to be changed at 5 000 km (3,000 mi) from the last engine oil change.
2. Turn OFF the ignition.
3. Disconnect the negative battery cable.
4. Remove the intake duct.
5. Remove the 2 screws (2) from the upper and lower air cleaner assembly sections.
6. Remove the upper air cleaner housing assembly (1).
7. Without disconnecting the PCM connectors (1), remove the PCM (3) and harness from the PCM housing (2).
8. Disconnect the PCM connectors (1).
Installation Procedure
1. Reconnect the PCM connectors (1).
NOTE: Refer to Fastener Notice in Service Precautions.
Tighten the connectors to 8 N.m (71 lb in).
2. Carefully reinstall the PCM (3) and harness into the PCM housing (2).
3. Install the upper air cleaner housing assembly (1).
4. Install the 2 screws (2) into the upper and lower air cleaner assembly sections.
Tighten the screws to 4 N.m (35 lb in).
5. Install the intake duct.
6. Reconnect the negative battery cable.
7. The Replacement PCM will NOT allow secondary AIR pump operation until a total of 10 miles have been accumulated.
8. The new PCM must be programmed. Refer to Powertrain Control Module Programming and Setup (3.8L) in Programming and Setup. Programming and Relearning
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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