Written by Mike Steen - Technical Director
The Transmission Range Sensor (TRS) has 3 primary functions:
1. Provide a PARK/NEUTRAL start signal to the engine controller and the starter relay.
2. Turn the Back-up lamps on when the transmission is in REVERSE and the engine (ignition) is on.
3. Provide a transmission range signal to the instrument cluster.
This relatively simple sensor has caused us problems over the years.