Vehicle Speed Sensor (ES300 & GX470)

Wheel speed sensors on each wheel deliver an input signal to Anti-Lock Brake System (ABS) Electronic Control Unit (ECU). ABS ECU converts input signals from wheel speed sensors to a 4-pulse input signal to instrument cluster. Instrument cluster converts 4-pulse input signal to a rectangular waveform and then sends input signal to Engine Control Module (ECM). ECM determines vehicle speed by using input signal. ECM uses input signal for controlling fuel injection system and electronic control of automatic transmission/transaxle.