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What Does a Gear Position Sensor Do?

by Andrea Stein

Modern vehicles come equipped with numerous sensors that send information vital to overall function to control modules. The gear position sensor, or GPS, reacts based on gearshift variables.

Function

The gear position sensor, typically located on the transmission selector shaft or steering column mounting, consists of a series of switches, or electronic devices that either direct or divert power to circuits. These switches send information to the transmission control module regarding the current position of the gearshift.

Starter Operation

The gear position sensor contains a neutral safety switch which receives voltage from the starter solenoid once the key turns to the "start" position in the ignition. The neutral safety switch turns off operation of the starter if the vehicle’s transmission is placed in any gear other than park or neutral. This prevents the engine from starting while the transmission is in an incorrect gear.

Considerations

Gear position sensor failure can make transmission shifting difficult or cause the car not to start. Failure may be indicated by a "check engine" light, which should be checked by a certified mechanic.

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