Transmission Position Sensor/Switch: Description and Operation

Park/Neutral Position (PNP) Circuit:

PURPOSE
The PARK/NEUTRAL POSITION (PNP) switch indicates to the ECM when the transmission is in PARK or NEUTRAL.
This information is used by the ECM to control:
- Idle Air Control (IAC) valve operation
- Transmission Torque Converter Clutch (TCC) operation

OPERATION
The PNP switch contacts are closed to ground in park or neutral and open in drive ranges and reverse. The ECM supplies ignition voltage through a current limiting resistor to the switch and senses a closed circuit when voltage drops to less than 1 volt.

NOTE
Do NOT drive the vehicle with the PNP switch disconnected, since idle quality may be affected.