Vehicle Speed Sensor

The vehicle speed sensor is a magnetic inductive pickup that relays vehicle speed information to the PCM. The PCM uses this information in order to control shift timing, line pressure, and TCC apply and release.

The vehicle speed sensor mounts in the case at the speed sensor rotor, which is pressed onto the differential. An air gap of 0.27-1.57 mm (0.011-0.062 in) occurs between the sensor and the teeth on the speed sensor rotor. The sensor consists of a permanent magnet surrounded by a coil of wire. As the differential rotates, an AC signal is induced in the vehicle speed sensor. Higher vehicle speeds induce a higher frequency and a higher voltage measurement at the sensor.

Sensor resistance should measure between 981-1471 ohms at 20° C (68° F). Output voltage will vary with vehicle speed from a minimum of 0.5 volts AC at 25 RPM, to 200 volts at 1728 RPM.