Operation CHARM: Car repair manuals for everyone.

Circuit Operation

The Vehicle speed sensor generates a signal proportional to vehicle speed. the signal produced is a sine wave, which the Powertrain Control Module (PCM) processes into a square wave to supply inputs to the speedometer, Multi-Function Chime (MFC) Module and the Computer Command Ride (CCR) controllers (If Equipped).

The PCM takes the sensor/Voltage pulses from the vehicle speed sensor and uses them to close a solid-state output switch. The output terminal is switched to ground at a rate that is proportional to vehicle speed.