Transmission Description - Vehicles With: 8HP76 8-Speed Automatic Transmission, AWD (G2391364): Description: Sensors

Speed Sensors 

The turbine speed sensor and the output shaft speed sensor are Hall effect type sensors located in the mechatronic valve block and are not serviceable items. The TCM  monitors the signals from each sensor to determine the input (turbine) speed and the output shaft speed.

The turbine speed is monitored by the TCM  to calculate the slip of the torque converter clutch and internal clutch slip. This signal allows the TCM  to accurately control the slip timing during shifts and adjust clutch application or release pressure for overlap shift control.

The output shaft speed is monitored by the TCM  and compared to engine speed signals received on the FlexRay system bus from the PCM  . Using a comparison of the 2 signals the TCM  calculates the transmission slip ratio for plausibility and maintains adaptive pressure control.

Temperature Sensor 

The temperature sensor is also located in the mechatronic valve block. The TCM  uses the temperature sensor signals to determine the temperature of the ATF  . These signals are used by the TCM  to control the transmission operation. The TCM  uses the temperature signals to promote faster warm-up in cold conditions. The TCM  also uses the temperature signal to assist with ATF  cooling by controlling the transmission operation when high ATF  temperatures are experienced. If the sensor fails, the TCM  uses a default value and a Diagnostic Trouble Code(s) (DTC) is stored in the TCM  .