Vehicle Speed Sensor: Description and Operation

Vehicle Speed Sensor:

The Vehicle Speed Sensor (VSS) is a pulse generator which is mounted in the transaxle. A toothed reluctance ring rotates near a magnetic pick up, producing a voltage signal that is proportional to the vehicle speed. The speed sensor produces a weak signal. A vehicle speed sensor buffer amplifier is placed between the speed sensor and the ECM to amplify the speed signal. The buffer amplifier decodes the signal from the speed sensor to a digital signal, and sends it to the ECM. The ECM uses this signal to calculate miles per hour to operate the idle speed control system, Torque Converter Clutch (TCC), and to modify fuel delivery under certain vehicle conditions. A speed sensor or circuit which is not functioning properly will set a code E024.