Circuit Description

WARNING: This page is about a different car, the 2002 GMC Cab & Chassis Sierra and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The Input Speed Sensor (ISS) provides transmission input speed to the PCM. 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 forward clutch housing. The permanent magnet generator produces an AC voltage as the forward clutch housing rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the turbine shaft speed increases. The PCM converts the AC voltage into a digital signal. The PCM determines actual turbine speed using the digital signal. The PCM uses the input speed to calculate torque converter slip speed and gear ratios.

When the PCM detects a low or no input speed during high vehicle and high engine speeds, then DTC P0717 sets. For Federal emission vehicles, DTC P0717 is a type "C" DTC. For California emissions vehicles, DTC P0717 is a type "B" DTC.