The Transmission Range Sensor (TRS) is part of the solenoid module, which is mounted to the top of the valve body inside the transmission.The Transmission Range Sensor (TRS) has five switch contact pins that:Determine shift lever positionSupply ground to the Starter Relay in Park and Neutral only.Supply +12 V to the backup lamps in Reverse only.The TRS also has an integrated temperature sensor (thermistor) that communicates transmission temperature to the TCM and PCM.