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.
2008 Hummer H2 V8-6.2LFACTORY OEM SERVICE PROCEDURE
Ignition Switch: Service and Repair
Ignition and Start Switch Replacement
Special Tools
J-42759 Ignition Switch Connector Release Tool
Removal Procedure
Caution: Refer to SIR Caution (SIR Caution) .
1. Remove the driver knee bolster. Refer to Driver Knee Bolster Replacement (Driver Knee Bolster Replacement) .
2. Remove the theft deterrent module. Refer to Theft Deterrent Module Replacement (Service and Repair) .
3. Disconnect the passlock and key buzzer from the ignition lock cylinder case.
4. Insert release tool J-42759 into the ignition lock cylinder case to release the tabs on the ignition/start switch.
5. Pull the ignition/start switch out of the ignition lock cylinder case.
6. Disconnect the electrical connector from the ignition/start switch.
Installation Procedure
Important: The gears between the ignition/start switch and the ignition lock cylinder case must be in the correct position. Failure to do so will cause a misalignment of the gears in the ignition/start switch and the ignition lock cylinder case , which may result in a NO START or BATTERY DRAIN.
1. Verify the alignment of the gear (1) in the ignition/start switch (2). If the gear (1) is not in the position shown then turn the gear in the ignition/start switch (2) until you reach the correct position.
Important: In order to reach a stop while rotating the ignition lock cylinder case gear you MUST push and hold in the solenoid on the electric park lock.
2. Use a screwdriver to rotate the ignition lock cylinder case gear counterclockwise until it hits the stop.
3. Connect the electrical connector to the ignition/start switch.
4. Insert the ignition/start switch into the ignition lock cylinder case. The tabs (2) on the ignition/start switch MUST be seated inside the ignition lock cylinder case (1) for proper installation.
5. Use a screwdriver to rotate the ignition lock cylinder case gear clockwise to the START position allowing it to spring return into the RUN position.
6. Connect the passlock and key buzzer to the ignition lock cylinder case.
7. Install the theft deterrent module. Refer to Theft Deterrent Module Replacement (Service and Repair) .
8. Install the knee bolster. Refer to Driver Knee Bolster Replacement (Driver Knee Bolster Replacement) .
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.