Input Speed Sensor

The input speed sensor is a magnetic inductive pickup that relays input speed information to the PCM. The PCM uses A/T input speed information in order to control line pressure, TCC apply and release, and transmission shift patterns. This information is also used in order to calculate the appropriate operating gear ratios and TCC slippage.

The vehicle speed sensor mounts on the transmission case under the channel plate and next to the drive sprocket. An air gap of 0.08-2.12 mm (0.0032-0.834 in) occurs between the sensor and the teeth on the drive sprocket. The sensor consists of a permanent magnet surrounded by a coil of wire. As the turbine shaft drives the drive sprocket, an AC signal is induced in the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.

Sensor resistance should measure between 893-1127 ohms at 20° C (68° F). Output voltage will vary with the vehicle speed from a minimum of 0.5 volts AC at 300 RPM to 200 volts at 6000 RPM.