Removal
To remove the wheel speed sensor, perform the following steps.
Front wheel
Fig. 14.50. Front and rear wheel speed sensors: 1 – front wheel speed sensor rotor; 2 – bolt (25 Nm); 3 – front wheel speed sensor; 4 – rear wheel speed sensor; 5 – sensor bracket; 6 – rear wheel speed sensor rotor
1. Unscrew the bolt and remove sensor 3 (Fig. 14.50) of the front wheel speed.
Fig. 14.51. Location of the pole piece (1) of the wheel speed sensor
Caution! Be careful when handling the pole piece of the wheel speed sensor and the toothed surface of the rotor so as not to damage them against other parts (Fig. 14.51).
2. Remove rotor 1 (see Fig. 14.50) of the front wheel speed sensor together with the front wheel drive shaft. The rotor of the front wheel speed sensor is combined with the front wheel drive shaft and is non-separable.
Rear wheel
1. Loosen the bolt and remove the rear wheel speed sensor 4.
2. Unscrew the two bolts and remove the sensor bracket 5.
3. Remove rotor 6 of the rear wheel speed sensor.
Examination
1. Check the sensor pole tip surfaces for any metal particles and remove any if present.
2. Also check the pole piece for damage, and if any is found, replace the sensor.
3. Since there is a magnet installed inside the speed sensor, the sensor pole becomes magnetized, causing foreign metal objects to be easily attracted to it. In addition, if the pole piece is damaged, the sensor will not be able to detect the wheel speed correctly.
4. Measure the resistance between the sensor terminals, which should be within 1.28–1.92 kOhm.
5. If the internal resistance of the wheel speed sensor does not correspond to the nominal value, replace the sensor.
6. Check the sensor wires for damage, breaks or poor contact; if any are found, replace the wire with a new one.
To check for damage to the sensor wire, remove the wire mounting bracket from the body, then bend and pull the wire to check if the contact is temporarily broken.
Installation
Installation is carried out in the reverse order of removal, taking into account the following.
Fig. 14.52. Measuring the gap between the pole piece of the wheel speed sensor and the toothed surface of the rotor
1. When installing the rear wheel speed sensor, insert the measuring probe into the gap between the pole piece of the wheel speed sensor and the toothed surface of the rotor, set the nominal gap around the entire perimeter of the rotor within 0.3–0.9 mm and tighten the sensor bracket (Fig. 14.52).
Caution: Be careful when handling the pole piece of the wheel speed sensor and the toothed surface of the rotor to avoid damaging them against other parts.
2. Check the sensor output voltage.