Transmission Temperature Sensor (Hardwired)

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The Transmission Temperature Sensor is used to monitor the temperature of the transmission fluid. Power for the sensor is supplied by the TCM. Actual transmission fluid temperature is based on the resistance value of the temperature sensor located in the Transmission Range Sensor (TRS). The primary temperature inputs used by the TCM are the Transmission Temperature Sensor, Battery Temperature Sensor, ECT Sensor and in-gear run time. The engine must be running to get accurate temperature readings.
If the sensor fails, the TCM defaults to a fluid temperature which is calculated from a combination of inputs. The calculated fluid temperature is continually updated and retained in memory for 20 minutes after the Ignition Switch is turned OFF. On vehicles equipped with a BCM, the calculated temperature is retained for four hours. When the vehicle is started after an extended OFF time, the calculated fluid temperature is reinitialized at a value between the battery temperature and engine coolant temperature signals received from the PCM over the PCI Bus.