Gear Shift Module

On a shift-by-wire vehicle the gear selector is not a switch on a wire but a small module of its own, reading the lever and reporting the driver's intention as a message on the data bus. That makes the selector a participant in the vehicle's network rather than a mechanical control, with the consequence that it can fail by going silent as well as by misreading — and a transmission receiving no message holds its last state or falls back to a default rather than guessing. Mounted in the centre console directly beneath the cup holders on most vehicles, which is why spilled drinks account for a disproportionate share of its faults.

Also known as: shifter module, gear selector module, gsm, shift by wire module, selector control unit, electronic shifter

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Codes involving this component (58)

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