General Description

Vehicle Speed Sensor (Pulse Counter Type) Location/Installation:

Vehicle Speed Input And Output Circuits:

Purpose:
The Vehicle Speed Sensor (VSS) is a pulse counter type input that informs the PCM how fast the vehicle is being driven. The PCM processes the information and sends it to the Central Control Module (CCM), cruise control module and radio. The PCM uses this information to control A/T Torque Converter Clutch (TCC) system, A/T transmission gear switch system and M/T 1-4 upshift systems.

Operation:
The VSS system uses an inductive sensor, which is a permanent magnet surrounded by a coil of wire, mounted in the extension housing of the transmission. A toothed reluctor wheel rotates with the output shaft. As the teeth of the reluctor interfere with the magnetic field, an A/C voltage is induced in the wire coils. This A/C voltage signal increases in both frequency and amplitude as vehicle speed increases. The PCM monitors this signal and calculates the vehicle speed from the frequency of the signal. Vehicle speed information is then relayed to the cruise control module, central control module (for dashboard display and odometer calculations), and radio tuner head (for speaker volume control).