Description of functions

The speed sensor detects the wheel speed and sends the signal to the skid control computer (brake actuator Assembly). These signals are used for ABS control.

The speed sensor detects magnetic field changes in the magnetic rotor, where the N and S poles are evenly allocated in a circumferential direction, and generates a vehicle speed pulse.

With this vehicle speed pulse, the skid control computer (brake actuator Assembly) detects each wheel's speed.

NOTE: The following voltage outputs are the values when the vehicle harness connectors are connected to the skid control computer (brake actuator Assembly) and the speed sensor.

Fig 1: Speed Sensor Output Voltage Waveform

Courtesy of SUBARU OF AMERICA, INC.

Diagnostic codes	DTC detecting conditions	Faulty part
C1330 C1331	Speed sensor's power supply or signal line is shorted.	Front speed sensor Wiring harness or connector Skid control computer (brake actuator Assembly)
C1464 C1465	Signal values are outside the specified range when signals of the four speed sensors are compared. An abnormal wheel speed is detected.	Front speed sensor Front speed sensor, poor installation Wiring harness or connector Speed sensor rotor Skid control computer (brake actuator Assembly)