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.
Transmission Control Module (TCM) (4T65 AWD; 2003-2006): Function: Shift-Lock
To avoid any chance of the gear selector inadvertently moving from the P position, the car is also equipped with an electrically operated shift-lock function. This locks the interlock pin in the gear selector lever in the shift-lock section, locking the selector lever in the P position. To move the gear selector from the P position, the ignition must be switched on and the brake pedal depressed. (The stop lamp switch is activated.). The central electronic module (CEM) reads the position of the brake pedal via direct connection to the brake pedal sensor and transmits a signal to the gear selector module (GSM) to deactivate the solenoid in the gear lever selector. The solenoid lock pin is pushed in and the gear selector lock button can be pressed down as usual to select another gear. When the ignition is in position "0", the solenoid is deactivated. In this position the gear selector is mechanically locked by the ignition switch interlock.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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