Circuit Operation

The Vehicle Speed Sensor (VSS) is a Permanent Magnet (PM) generator attached to the transmission case extension. The final drive assembly has a toothed wheel (VSS rotor). As the final drive assembly rotates, an AC voltage is induced and transmitted to the Powertrain Control Module (PCM). The PCM converts the AC voltage into a digital signal.

The PCM uses vehicle speed to determine shift timing, TCC apply and release and gear ratio. VSS voltage will vary from 0.5 volts AC at 100 RPM to more than 100 volts AC at 6000 RPM. VSS resistance value is 981-1864 ohms.

If the PCM detects a large change in vehicle speed, then DTC P0503 sets. DTC P0503 is a Type B DTC.