Front

Front Speed Sensor:

1. Inspect Speed Sensor.
(a) Disconnect the Speed Sensor connector.

Measure Resistance Between Terminals Of Front Speed Sensor:

(b) Measure the resistance between terminals.
Resistance: 0.6 - 2.5 k ohms
If resistance value is not as specified, replace the sensor.

Check For No Continuity Between Terminal And Sensor Body:

(c) Check there is no continuity between each terminal and sensor body. If there is continuity, replace the sensor.
(d) Connect the Speed Sensor connector.
2. Inspect sensor installation.

Check Sensor Installation:

(a) Check the sensor installation bolt is tightened properly. If not, tighten the bolt.
Torque 7.8 Nm (69 ft. lbs.)
(b) Check there is no clearance between the sensor and Steering Knuckle.
3. Visually inspect sensor rotor serrations.
(a) Remove the Front Axle Hub.

Inspect Sensor Rotor Serrations:

(b) Inspect the sensor rotor serrations for scratches, cracks, warping or missing teeth. Install the front axle hub.

CAUTION: Be careful not scratch the sensor rotor serrations.

4. Inspect Speed Sensor and sensor rotor serrations by using an oscilloscope (reference)
(a) Remove the Anti-Lock Brake System (ABS) Electronic Control Unit (ECU) with connector still connected.
(b) Connect the oscilloscope to the terminals FR+, FR- and Ground (GND) of ABS ECU.

Inspect Speed Sensor And Sensor Rotor Serrations With Oscilloscope:

(c) Drive the vehicle at about 30 km/h (19 mph), and check the signal waveform.

NOTE: When the waveform is abnormal, inspect the sensor tip and rotor. If there is no abnormality on the sensor tip and rotor, only replace the grease.

5. Check Speed Sensor signal.