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.
Gear Selector Module (GSM)
The gear selector assembly is located in the tunnel console and is mechanically connected to the transmission by a cable which moves the shuttle valve in the transmission control system. The Gear Selector Module (GSM) is located on the top panel of the gear selector assembly. The Gear Selector Module (GSM) is supplied with power from the Central Electronic Module (CEM). The Gear Selector Module (GSM) communicates with the Transmission Control Module (TCM) via serial communication, to light up gear position indication amongst other things. Gear position indication consists of a row of LEDs in the top panel of the gear selector assembly.
The Central Electronic module (CEM) has a cable which is directly connected to the Gear Selector Module (GSM) to control the shiftlock solenoid. The supply of power and ground for the solenoid are directly connected to the Gear Selector Module (GSM).
The switch for winter program (W) is located on the top panel of the gear selector assembly. Upon activation the switch sends a request to activate the winter program (Winter mode) to the Transmission Control Module. The Transmission Control Module then determines whether or not the winter program is possible.
The Gear Selector Module can be diagnosed. In the event of a fault a signal on fault status is sent to the Transmission Control Module which then stores any diagnostic trouble codes.
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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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