Inspection Using An Oscilloscope (Reference): Wheel-Speed

ABS HU/CM terminal:
1. RR: A (+) - B (-)
2. LR: C (+) - F (-)
3. RF: D (+) - G (-)
4. LF: E (+) - I (-)
Oscilloscope setting:
1. 1 V/DIV (Y), 2 ms/DIV (X), AC range
Vehicle condition: Driving 30 km/h (18.6 MPH)
NOTE:
- As vehicle speed increases, period of wave shortens.
- If there is malfunctioning in the sensor rotor, wave profile warps.
Fig 1: Wheel-Speed Oscillations
Courtesy of MAZDA MOTORS CORP.