The speed sensor on these vehicles is located on the top of the rear differential unit.
See Figure 1
- Remove the speed sensor from the rear differential.
- Confirm that the resistance between the connector terminals is 420-520 ohms.
- Measure the insulation resistance between the terminals 1, 2 and the speed sensor body. The standard value is 100 kilo-ohms or more.
- If the speed sensor fails either of these two tests, replace the speed sensor with a new unit.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable from the battery.
- Raise the rear of the vehicle and support with jackstands. Block the front wheels with wheel chocks.
- Locate the speed sensor mounting position on the differential and trace the cable back along its route until the connector is reached. Unplug the speed sensor wiring harness connector.
- Remove the several retaining brackets holding the speed sensor cable in place on the rear axle assembly. Make certain to note the locations of the various brackets and bolts.
- Loosen the retaining ring of the speed sensor on the differential by unscrewing it. Once the retaining ring has been loosened, pull the speed sensor out of the rear differential.
Be careful when handling the pole piece at the tip of the speed sensor not to damage it by striking it against other parts.
- Insert the speed sensor into the rear differential unit and tighten the retaining ring until snug.
- Route the speed sensor cable along its original placement. Fasten it in place with the various cable brackets. Plug the harness connectors back together.
- Lower the vehicle to the ground.
- Connect the negative cable to the battery.
- Have the system rechecked if a new speed sensor was installed and the problem continues.