Transmission Range Sensor: Description

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Range Sensor (TRS) (Fig 1) has 3 primary functions:

Provide a PARK/NEUTRAL start signal to the engine controller and the starter relay.
Turn the Back-up lamps on when the transmission is in REVERSE and the engine (ignition) is on.
Provide a transmission range signal to the instrument cluster.

Fig 1: Identifying Transmission Range Sensor

Courtesy of DAIMLERCHRYSLER CORP.

The sensor is mounted in the transmission housing near the valve body, just above the pan rail. It's in the same position as the Park/Neutral switch on other transmissions. The TRS contacts a cammed surface on the manual valve lever. The cammed surface translates the rotational motion of the manual lever into the linear motion of the sensor. The cammed surface on the manual lever is comprised of two parts controlling the TRS signal: The insulator portion contacts the switch poppet when the manual lever is not in PARK or NEUTRAL. The manual lever itself contacts the poppet when the lever is in PARK or NEUTRAL; providing a ground for the signal from the starter relay and the JTEC engine controller.