Inspection procedure

1. Check that there is no difference between the speed value output from the speed sensor displayed by the hand–held tester and the speed value displayed by the speedometer when driving the vehicle.

   Ok: there is almost no difference in the displayed speed value.

1. 1
   Disconnect the skid control sensor connector.
2. 2
   measure resistance between terminals 1 and 2 of the skid control sensor connector.

   Ok: resistance: 2.2 Kw or less

3. 3
   measure resistance between each of terminals 1 and 2 of skid control sensor connector and body ground.

   Ok: resistance: 1 mw or higher

   

1. Check for open and short circuit in harness and connector between each skid control sensor and skid control ecu

(Reference) inspection using oscilloscope

1. 1
   connect the oscilloscope to the terminals rr+ – rr– and rl+ – rl– of the skid control ecu.
2. 2
   drive the vehicle at about 30 km/h, and check the signal waveform.

• as the vehicle speed (wheel revolution speed) increases, a cycle of the waveform becomes shorter and the fluctuation in the output voltage becomes greater.
• When noise is identified in the waveform on the oscilloscope, error signals are generated due to the speed sensor rotor’s scratches, looseness or foreign matter deposited on it.

1. Check the sensor installation.

   Ok: there is no clearance between the sensor and rear axle carrier.

1. 1
   Remove the skid control sensor .
2. 2
   check the sensor tip.

   Ok: no scratches or foreign objects on the sensor tip.

   

1. Check the sensor rotor serrations.

   Ok: no scratches, missing teeth or foreign objects.