ABS Wheel Speed Sensor - Front

This procedure covers the removal and replacement of the front ABS wheel speed sensor on a 1994-2007 Dodge Ram 2500 with 5.9L Cummins diesel engine and 4WD.

Warnings

Tools required

Parts

• Front ABS wheel speed sensor × 1 — Use OEM specification or quality aftermarket
• Electrical connector cleaner (optional) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Loosen wheel lug nuts while vehicle is still on the ground
4. Raise front of vehicle and support securely on jack stands at frame rails
5. Remove wheel completely from the side being serviced
6. Spray ABS sensor mounting bolt and sensor body with penetrating oil and allow to soak for 10-15 minutes if sensor appears corroded

Procedure

1. 1

   Locate the ABS wheel speed sensor
   The front ABS wheel speed sensor is mounted at the wheel hub/knuckle assembly on the solid front axle. Identify the sensor body and its electrical connector. The sensor wire routes up toward the inner fender area. Note the wire routing for reinstallation. Identify the sensor body and its electrical connector. The sensor wire routes up toward the inner fender area. Note the wire routing for reinstallation.
2. 2

   Disconnect the electrical connector
   Trace the sensor wire harness to the electrical connector. Press the release tab and carefully disconnect the connector. If connector is difficult to release, use a small flat blade screwdriver to gently assist with the release tab. Inspect connector terminals for corrosion or damage.
3. 3

   Remove wire harness retaining clips
   Follow the sensor wire from the sensor to the connector and remove any retaining clips or brackets securing the wire to the chassis or suspension components. Some clips may be push-type while others may have small bolts. Keep track of all clips for reinstallation.
4. 4

   Remove the ABS sensor mounting bolt
   Using the appropriate socket, carefully remove the single bolt securing the ABS sensor to the steering knuckle. If bolt is seized, apply additional penetrating oil and allow to soak before attempting removal. Do not use excessive force which could break the bolt in the knuckle.
   Torque spec

   ABS Sensor Bolt10 Nm (7 lb-ft)
5. 5

   Extract the sensor from the hub
   Gently pull the sensor straight out from the steering knuckle bore. If sensor is stuck, carefully wiggle it back and forth while pulling. Do NOT use pliers on the sensor body as this can damage it. If severely seized, apply heat to the knuckle (not the sensor) and continue working it free. Avoid damaging the tone ring teeth visible inside the bore.
6. 6

   Clean the sensor mounting bore
   With the sensor removed, use a wire brush to thoroughly clean the sensor bore in the steering knuckle. Remove all rust, dirt, and debris. Spray with brake cleaner and wipe clean. Inspect the bore for damage or deep corrosion. Check the tone ring teeth inside the hub for damage, missing teeth, or excessive rust buildup.
7. 7

   Prepare the new sensor
   Remove the new sensor from packaging and inspect for damage. Apply a thin coat of dielectric grease to the sensor O-ring and tip (if not pre-applied). Do not apply grease excessively as it can attract metal particles that interfere with sensor operation. Ensure the sensor tip is clean.
8. 8

   Install the new sensor
   Carefully insert the new sensor straight into the steering knuckle bore. Push firmly until it seats completely - the mounting hole in the sensor should align with the threaded hole in the knuckle. Ensure the sensor is fully seated before installing the bolt. The air gap is pre-set by the sensor design and does not require adjustment.
9. 9

   Install and torque the sensor mounting bolt
   Insert the ABS sensor mounting bolt and start it by hand to ensure proper thread engagement. Using a torque wrench, tighten the bolt to the specified torque. Do not exceed the specified torque as the sensor housing can crack.
   Torque spec

   ABS Sensor Bolt10 Nm (7 lb-ft)
10. 10

    Reinstall wire harness clips and connect electrical connector
    Route the sensor wire harness following the original path noted during disassembly. Reinstall all retaining clips and brackets to secure the wire away from moving suspension and steering components and the front axle shaft. Ensure wire has adequate slack and will not be stretched during suspension travel. Clean the electrical connector terminals if needed and reconnect the connector firmly until the release tab clicks into place.
11. 11

    Reinstall the wheel
    Clean the wheel hub mounting surface and reinstall the wheel. Start all lug nuts by hand to ensure proper thread engagement. Snug lug nuts in a star pattern but do not fully torque yet.
    Torque spec

    Wheel Lug Nuts183 Nm (135 lb-ft)
12. 12

    Lower vehicle and perform final torque
    Lower the vehicle until the tire just contacts the ground but vehicle weight is still on jack stands. Torque wheel lug nuts to specification in a star pattern. Lower vehicle completely and remove jack stands. Perform final torque verification of lug nuts in star pattern.
    Torque spec

    Wheel Lug Nuts183 Nm (135 lb-ft)

Reassembly

1. Ensure all wire harness clips are securely fastened and wire routing prevents interference with suspension components
2. Verify electrical connector is fully seated and locked
3. Double-check that wheel lug nuts are torqued to specification in star pattern

Verification

• Start the engine and verify the ABS warning light illuminates during bulb check and then turns off within a few seconds
• If ABS light remains on, use a scan tool to check for ABS codes and verify sensor operation
• Test drive vehicle at speeds above 5 mph to allow ABS system to self-test - ABS light should remain off
• Perform a gentle ABS activation test in a safe area to confirm system is functioning properly
• Inspect for any rubbing or interference between sensor wire and suspension components during steering and suspension travel
• Re-verify wheel lug nut torque after first 50-100 miles of driving

Related trouble codes on this vehicle

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