Vehicle Speed Sensor: Description and Operation
Vehicle Speed Sonsor Circuit:
PURPOSE
The sensor is used by the ECU to determine vehicle speed.
LOCATION
The vehicle speed sensor is mounted inside the speedometer assembly.
CONSTRUCTION
The sensor consists of a reed switch that is closed by a rotating magnet in the speedometer.
OPERATION
As the switch rotates, continuity between terminals A and B is interrupted 4 times per revolution. This reference signal is sent to the ECU for determining vehicle speed.