Transmission Range (TR) Sensor
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The 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 EPC pressure. The TR sensor is located on the top of the transaxle, and also contains the neutral/start, and reverse lamp circuits.