ABS Wheel Speed Sensor Replacement

An ABS wheel speed sensor is used to send feedback reference voltage to the system's computer which controls the system. Your vehicles ABS brake system relies on these speed sensors which connect to an electronic module while using a fluid pump motor to activate the system.

Electronic sensors are located at all four wheels to monitor the rotation speed of each tire. This monitoring is performed to help the main controller differentiate brake system pressure to each wheel when the brake system is abruptly applied.

By doing this the wheel that is rotating at a lesser speed than the remaining wheels will experience a brake fluid pressure drop to help allow the wheel to start rotating at the same rate as the remaining wheels.

These sensors are prone to failure and will usually illuminate a red or yellow brake system warning light when there is trouble with one or more of them. To determine if a sensor has failed there are one of two methods that can be used.

The first method is to attach an expensive system scan tool to retrieve the trouble codes, once the code is discovered finding the definition is next step which will pinpoint the particular bad sensor.

If no scanner is available an alternative method can be used. Remove the electrical connector from each wheel sensor and by using a hand held multi-meter test the voltage produced while rotating the wheel, if no voltage is produced the sensor is bad.

See Also: Testing an ABS wheel sensors These sensors are not to difficult to repair and will take about an hour and cost between $25 and $140 depending if the sensor is separate from the hub or not, find the sensor your need on Amazon, dealer or the local parts store. Please follow this guide I have created for you to repair your own sensor.

Some sensors can be removed separately while others are integrated into the wheel bearing assembly which is what I have shown here.

Watch the video below, then continue to the follow article below to gain tips and additional information that might be missed in the video.

Tools and supplies needed to complete the repair 

  • Replacement wheel speed sensor
  • Tool set
  • Shop towels
  • Protective eye wear
  • Work gloves
  • Floor jack
  • Jack stands
Before you begin, park the car on level ground with the emergency brake set. If the vehicle needs to be raised do so safely with jack stands rated to hold the weight of your vehicle, now let's get started.

Step 1

Remove the wheel cover if needed and break the lug nuts loose one or two turns using a lug wrench supplied with the spare tire. Once completed use a floor jack under the frame or control arm to lift the vehicle, once raised use a jack stand under the frame for safety. After you have finish removing the lug nuts, remove the tire. Slide the tire under the vehicle for an additional measure of safety.

Removing Wheel

Step 2

Once the tire has been removed, locate and remove the brake caliper mounting bolts to remove the caliper. After the bolts have been remove, grasp the caliper and rock it back and forth slightly to loosen and remove. Then place the caliper in a secure spot, do not allow it to hang by the brake hose, this can damage the hose and cause a safety issue.

Without stretching the brake hose set the caliper safety to the side and use a zip tie to hold it in place if needed. Remove both brake pads and place in a clean area, never allow grease or oil to contact the brake pad or rotor surface.

Removing the Caliper Mounting Bolts

Step 3

Loosen and remove the brake caliper mounting bracket bolts to remove the bracket. These can be fairly tight so get a good grip on the wrench or socket being used. Be sure to hold the bracket because once the bolts are removed it can fall causing damage to the part and possibly hurt you as it falls.

Remove Brake Caliper Mounting Bolts

Step 4

With the caliper mounting bracket out of the way it's time to remove the brake rotor, if the rotor is stuck on the hub use a hammer to "shock" the rotor loose by striking it on the flat surface of the rotor and against the bearing hub or axle (The rotor can be tight due to rust and the press of the lug nuts while holding the tire on).

With this completed remove the rotor, again this part is heavy and can cause harm if it falls so get a good grip on it.

Remove Brake Rotor

Step 5

After the rotor has been removed, it will expose the sensor which can be replaced separately on some models, or along with the bearing hub. Some sensors are simply bolted to the rear of the spindle or backing plate on the rear of the car, in which case the removal of the brake assembly is not needed. Be sure to inspect which kind of sensor configuration you have before beginning the job.

ABS Wheel Sensor

Step 6

Use a socket or wrench to remove the sensor mounting bolt which can be Allen, hex or torx head bolts. After the mounting bolt has been removed, grasp the sensor to remove it from the bearing hub or spindle. While the sensor has been removed inspect the sensor stator ring by rotating the hub to confirm there is no damage existing to the ring. If the ring shows signs or wear or missing teeth replacement is required and could be the cause of the warning light.

Removing Wheel Sensor Mounting Bolt

Step 7

Locate the sensor wiring connector which is usually near the frame or upper control arm. Release the safety clasp and gently remove the connector from the wiring harness. Match the new sensor to the old unit to ensure proper installing and operation, confirm the electrical connector is clean from dirt and grease before reassembly.

Once the sensor has been replaced, the ABS warning light should go out without resetting or clearing the codes in most cases. Some older systems such as Nissan or Volkswagen might require a scan tool to reset the system, but this not typical.

ABS Wheel Sensor Wiring Connector
If you have any questions about this article please visit our forum where hundreds ABS wheel sensor questions have already been answered.

 

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