Transmission Position Sensor/Switch: Description and Operation

Park/Neutral Switch (Auto. Trans):

The PARK/NEUTRAL switch indicates to the computer when the transmission is in PARK or NEUTRAL. This information is used by the computer for ignition timing, Idle Air Control (IAC) operation, EGR and Canister Purge operation as well as transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected.