Circuit Description
The automatic transmission input speed sensor (ISS) provides transmission input speed to the transmission control module (TCM). The ISS is a permanent magnet generator. The sensor mounts into the transmission case and maintains a slight air gap between the sensor and the drive sprocket. The ISS produces an AC voltage as the drive sprocket rotor teeth pass through the magnetic field of the sensor. The AC voltage level increases as the turbine shaft speed increases. The TCM converts the AC voltage into a digital signal. The TCM determines actual turbine speed using the digital signal. The TCM uses the input speed to calculate torque converter slip speed, and gear ratios.
When the TCM detects a low input speed and the vehicle has a large vehicle speed, DTC P0717 sets. DTC P0717 is a type B DTC.