Transmission Input Speed Sensor (4-Speed A/T)

The input speed sensor is a two-wire magnetic pick-up device that generates an AC voltage signal as rotation occurs. It is threaded into the transaxle case and sealed with an "O" ring. See Figure . The sensor is considered a primary input to the Transmission Control Module (TCM). The input speed sensor provides information on how fast the input shaft is rotating. As the teeth of the input clutch hub pass by the sensor coil, an AC voltage signal is generated and sent to the TCM. The TCM interprets this information as input shaft RPM. The TCM compares the input speed signal with the output speed signal to determine transmission gear ratio, speed ratio error detection and clutch volume index. The TCM also compares the input speed signal and the engine speed signal to determine torque converter clutch slippage and torque converter element speed ration.