Code 24, Vehicle Speed Sensor (VSS): Notes

Fig 1: Code 24 - Schematic

Courtesy of GENERAL MOTORS CORP.

VSS, mounted on transaxle extension housing, is a permanent magnet generator that provides Powertrain Control Module (PCM) with pulsing AC voltage signals. VSS produces signals when vehicle speed is greater than 3 MPH. Voltage level and pulses increase with vehicle speed. PCM receives and converts signals.

1. VSS only produces a voltage signal if drive wheels are turning at speeds greater than 3 MPH.
2. Before replacing PCM, check MEM-CAL for correct application.