Front Wheel Speed Sensor: Inspection

Remove the instrument panel lower cover. Ref. to REMOVAL , Instrument Panel Lower Cover.
Set the probe of oscilloscope to TCM harness connector.

Fig 1: TCM Harness Connector Terminal Identification
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle and raise the vehicle speed up to 20 km/h (12 MPH).
Check the waveform of front wheel speed sensor when vehicle speed is at 20 km/h (12 MPH).

Fig 2: Identifying Signal Waveform
Courtesy of SUBARU OF AMERICA, INC.