Examination
1. Disconnect the sensor connector (indicated by an arrow).
2. Raise the car and place it on stands. Connect a voltmeter to the sensor. Block one of the front wheels and rotate the other wheel by hand. The voltmeter should register a pulsating voltage from 0 to 5 volts. If not, replace the sensor.
Replacement
1. Disconnect the sensor connector, unscrew the fixing screw and remove the sensor. Replace O-ring.
2. Installation is carried out in the reverse order of removal.