Range Rover (LH) V8-3.9L (1989)
Vehicle Speed Sensor: Description and Operation
PURPOSE AND OPERATION
The vehicle speed sensor provides road speed data to the electronic control unit (ECU). The ECU in turn detects vehicle movement from the road
speed input and ensures that idle speed control mode is disengaged. Should the vehicle speed sensor fail in service, the ECU idle speed control
would become erratic.
The vehicle speed sensor also provides road speed data to the electric speedometer and cruise control ECU.