Gear Selector Module (GSM)
The gear selector assembly is in the tunnel console. It is mechanically connected to the transmission by a cable which moves the gear valve in the transmission control system. The gear selector module (GSM) is on the top panel of the gear selector assembly. The gear selector module (GSM) is powered by the transmission control module (TCM). The gear selector module (GSM) uses serial communication to communicate with the transmission control module (TCM) to light the gear position indicator for example. The gear selected is indicated by a row of LEDs in the top panel on the gear selector assembly.
There is a directly connected cable from the transmission control module (TCM) to the gear selector module (GSM) which controls the shift-lock solenoid. The power supply and ground for the shift-lock solenoid are directly connected to the gear selector module (GSM).
The switch for winter mode (W) is located in the lever carrier's top panel (switch and function are discontinued from model year 2008). At activation, the switch sends a request to activate winter mode to Transmission control module (TCM) (TCM). Transmission control module then decides if winter mode is possible or not.
There are diagnostics for the gear selector module. In the event of a fault, a signal about the fault status is transmitted to the transmission control module where any diagnostic trouble codes are stored.