Transmission Position Sensor/Switch: Description and Operation

The PNP switch indicates to the PCM when the transmission is in park, neutral, or drive. This information is used for the EGR and IAC valve operation. The PNP switch is part of the neutral/start and backup light switch assembly.

IMPORTANT: Idle quality will be affected if the vehicle is driven with the PNP switch disconnected. Having the switch disconnected may also cause a VSS DTC to set.