DTC 24, Vehicle Speed Sensor: Notes

ECM supplies a 5 volt signal to Vehicle Speed Sensor (VSS). While vehicle is moving, a reed switch inside VSS will open and close, 4 times per revolution, toggling 5 volt signal high and low. ECM then converts this toggled high/low voltage into a vehicle speed that is displayed as MPH. DTC 24 will set if a constant voltage signal (high or low) is detected at ECM for at least 4 seconds, with engine running and vehicle moving.

1. Checks if malfunction is intermittent.
2. If VSS is not receiving 5 volts from ECM, DTC 24 will set. Checks for open or short to ground in Yellow/Green wire or a faulty ECM.
3. Checks instrument cluster printed circuit for cracks or bad connections, an open in Black/Blue wire or a faulty VSS.