buick Workshop Repair Guides

Buick Workshop Service and Repair Manuals

Vehicle Speed Sensor|Testing and Inspection > < VSS - Revised Test A (Speedometer is Inaccurate)|Page 4266
Page 1
background image

Vehicle Speed Sensor: Description and Operation

CIRCUIT OPERATION:

The vehicle speed sensor generates a signal proportional to vehicle speed. The signal produced is a sine wave, which the PCM processes into a
square wave to supply inputs to the speedometer, Multi-Function Chime (MFC) module and the Computer Command Ride (CCR) controller (if
equipped).

The PCM takes the sensor voltage pulses from the vehicle speed sensor and uses them to close solid-state output switches. The output terminals
are switched to ground at a rate that is proportional to vehicle speed.

Vehicle Speed Sensor|Testing and Inspection > < VSS - Revised Test A (Speedometer is Inaccurate)|Page 4266