Transmission Position Sensor/Switch: Description and Operation

Park-Neutral-Backup Lamp Switch:

Wiring Diagram For VSS, and Park/Neutral Relay.:

PURPOSE
The PARK/NEUTRAL switch contacts are a part of the neutral start switch and are closed in park or neutral, and open in drive ranges. 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), and Transmission Torque Converter Clutch (TCC) operation. DO NOT drive the vehicle with the PARK/NEUTRAL switch disconnected, since idle quality may be affected.


OPERATION
The gear selector switch, located on the steering column, opens and closes switch contacts which then pass voltage through a diode module to open and close the contacts on the Park/Neutral Reverse Relay. The Engine Control Module (ECM) will then read the signal directly from the relay.