Code 72, Vehicle Speed Sensor Circuit: Notes

A vehicle speed signal is provided to the PCM by the Vehicle Speed Sensor (VSS). This sensor produces a pulsing waveform voltage whenever vehicle speed is greater than 2 MPH. Voltage level or amplitude and frequency of pulses increases with vehicle speed. PCM conditions this signal and calculates vehicle speed. The PCM will then supply the signal to the instrument panel (4000 pulses per mile).

NOTE: Test numbers refer to numbers on diagnostic chart.

Sensor will produce a signal and vehicle speed only if the wheels are turning faster than 3 MPH.
If circuits 389, 400 and 401 are okay, and if speedometer works correctly, DTC 24 is being caused by a faulty PCM or an incorrect program.