Speed Sensor - Input: Operation
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 (Fig 1), an AC voltage is generated and sent to the PCM/TCM. The PCM/TCM interprets this information as input shaft RPM.
The PCM/TCM compares the input speed signal with output speed signal to determine the following:
- Transmission gear ratio
- Speed ratio error detection
- CVI calculation
The PCM/TCM also compares the input speed signal and the engine speed signal to determine the following:
- Torque converter clutch slippage
- Torque converter element speed ratio