Circuit Description

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. 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 transmission control module (TCM) in order to control line pressure, torque converter clutch (TCC) apply and release and transmission shift patterns. This sensor is also used to calculate the appropriate gear ratios and TCC slippage.

This diagnostic indicates stuck, erratic or intermittent conditions in the system.

If the TCM detects an unrealistically large change in the ISS high signal in a short period of time, then DTC P0716 sets. DTC P0716 is a type B DTC.