Transmission Range (TR) Sensor
The TCM uses the position of the transmission range (TR) sensor, housed in the TCM, to determine the selected gear range from the range selector lever.
The sensor completes the start circuit in P and N, and the back-up lamp circuit in R. The sensor also opens/closes a set of switches that are monitored by the TCM to determine the position of the manual lever (P, R, N, D, 3, 2 and 1).