Transmission Position Sensor/Switch: Description and Operation

When the gear position is "P" (A/T models only) or "N", park/neutral position (PNP) switch is "ON".

ECM detects the position because the continuity of the line (the "ON" signal) exists.

For A/T models, the park/neutral position (PNP) switch assembly also includes a transmission range switch to detect selector lever position.