Circuit Description

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

The automatic transmission input speed sensor (ISS) is a permanent magnet with a coil of wire wound around it. The ISS mounts in the case cover facing the reluctor wheel of the input shaft. As the reluctor wheel is driven by the turbine shaft, an AC signal is induced in the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage at the sensor.

There is a fixed air gap between the sensor and the teeth on the sensor reluctor wheel. The ISS input is used by the TCM in order to control line pressure, TCC apply and release and transmission shift patterns. This sensor is also used to calculate the gear ratios and TCC slippage.

If the TCM detects a low input speed while the vehicle and engine speeds are high, then DTC P0717 sets. DTC P0717 is a type B DTC.