Only 4WD models are equipped with separate rear wheel speed sensors. 2WD models do not utilize separate rear wheel speed sensors; instead their control modules utilize the VSS signal in order to determine the rate at which the rear wheels are spinning/approaching lock-up. In this way, the system monitors the rear wheel speed in the same fashion as the RWAL system described earlier in this section.
REMOVAL & INSTALLATION
Individual Wheel Type
See Figure 1
- Raise and support the rear of the vehicle safely on jackstands.
- Remove the tire and wheel assembly.
- Matchmark and remove the brake drum/disc.
- Remove the primary brake shoe. Refer to the brake shoe procedure in this section.
- Disengage the sensor wiring at the connector.
- Remove the sensor wire from the rear axle clips.
- Remove the 2 bolts holding the sensor to the brake backing plate, then remove the sensor by carefully working the wire through the hole in the backing plate.
- Route the wire through the hole in the backing plate and fit the sensor into position.
- Install the retaining bolts and tighten to 26 ft. lbs. (35 Nm).
- Secure the sensor wire within the rear axle clips.
- Engage the sensor wiring to the harness connector.
- Install the primary brake shoe.
- Align and install the brake drum/disc.
- Install the tire and wheel assembly, then remove the jackstands and carefully lower the vehicle.
See Figure 2
The speed sensor is not serviceable and must be replaced if malfunctioning. The sensor is usually located in the left rear of the transmission case.
The speed sensor may be tested with an ohmmeter. The correct resistance is normally 900-2000 ohms. To remove the speed sensor:
- Raise and support the vehicle safely using jackstands.
- Disengage the electrical connector from the speed sensor.
- If equipped, remove the sensor retaining bolt.
- Remove the speed sensor. Place a container below the sensor to catch fluid when the sensor is removed.
If equipped with the 4L30-E automatic transmission, use J-38417 or an equivalent speed sensor remover/installer tool whenever the sensor is serviced.
- Remove and discard the O-ring used to seal the sensor. Discard the O-ring.
- When installing, coat the new O-ring with a thin film of transmission fluid.
- Install the O-ring and speed sensor.
- If a retaining bolt is used, tighten the bolt to 97 inch lbs. (11 Nm) in automatic transmissions, or 107 inch lbs. (12 Nm) for manual transmissions.
- Engage the wire harness to the sensor.
- Remove the jackstands and carefully lower the vehicle.