Transmission Position Sensor/Switch: Description and Operation

Transmission Range Sensor (switch) (A/T vehicle only)
This switch is installed on the automatic transmission. ECM (PCM) detects transmission range by monitoring the ON/OFF signal from this switch and uses it as one of the signals to control the fuel injector, IAC valve and automatic transmission.

Electric Load Signal
This signal is sent from each circuit of head & small (or clearance) lights, heater fan, stop light and rear window defogger. ECM (PCM) uses it as one of the factors for controlling IAC valve.