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.
Engine Control Module: Service and Repair
2005 Pontiac G6 V6-3.5L VIN 8SECTION Service and Repair
POWERTRAIN CONTROL MODULE (PCM) REPLACEMENT
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 programmed 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. Disconnect the negative battery cable.
3. Rotate the lever lock to the up position in order to release the connector.
4. Disconnect the body harness electrical connector from the powertrain control module (PCM).
5. Rotate the lever lock to the up position in order to release the connector.
6. Disconnect the engine harness electrical connectors from the PCM.
7. Release the retaining tab located in the battery box lower half using a small screwdriver or other suitable tool.
8. Remove the PCM by lifting upward after releasing the tab.
INSTALLATION PROCEDURE
1. Slide the PCM into the PCM bracket on the front of the battery box.
2. Push down on the PCM until the retaining tab snaps into place.
3. Connect the engine harness electrical connectors to the PCM.
4. Rotate the lever locks downward to secure the connectors.
5. Connect the body harness electrical connectors to the PCM.
6. Rotate the lever lock downward to secure the connectors.
7. Connect the negative battery cable.
IMPORTANT: Following the PCM reprogramming, the PCM will have to learn the crankshaft position (CKP) variation for misfire diagnostics.
8. If a NEW PCM was installed, reprogram the PCM. Refer to Powertrain Control Module Programming and Setup in Programming and Setup.
Programming and Relearning
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.