Transmission Temperature Sensor
The Transmission Range Sensor (TRS) has an integrated thermistor that the Transmission Control Module (TCM) uses to monitor the transmission's sump temperature. See Figure . Since fluid temperature can affect transmission shift quality and converter lockup, the TCM requires this information to determine which shift schedule to operate in. The powertrain control module also monitors this temperature data so it can energize the vehicle cooling fan(s) when a transmission overheat condition exists. If the thermistor circuit fails, the TCM will revert to calculated oil temperature usage.