Transmission Position Sensor/Switch: Description and Operation

The Powertrain Control Module (PCM) sends a voltage signal to the Transmission Range (TR) sensor. The TR sensor incorporates a series of step down resistors which act as a voltage divider. The PCM monitors this voltage which corresponds to the position of the transmission range selector lever (P, R, N, D, 2, 1) to determine desired gear and Electronic Pressure Control (EPC) pressure. The TR sensor is located on the top of the transaxle, and also contains the neutral/start, and backup lamp circuits.