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.
2009 Hummer H3 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Circuit/System Verification
- Ignition ON, vehicle in PARK, observe the scan tool TCM TR SW parameter. The parameter should indicate PARK.
- If not the specified value, refer to Range Selector Displays Incorrect Range .
- Observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The parameter should change between Applied and Released.
- If the parameter does not change between the specified values, refer to Stop Lamps Malfunction .
- Press the brake pedal, the vehicle operator should be able to move the shifter out of the PARK position.
Factory Service Tools
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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.