How to Replace A Wheel Speed Sensor (Step-by-Step Guide)

Replacing a speed sensor as a DIY isn’t difficult. However, you need the right tools and should know your car parts. Sometimes, you may need to remove brake components, such as the brake caliper, brake pads, and brake rotor, to access the speed sensor. 

If you’re unsure, it’s best to have a professional replace the ABS wheel speed sensor for you or have a mobile mechanic drop by to help you out.

Here’s how they’ll do it: 

1. Engage the parking brake and disconnect the negative battery cable.
2. Raise your vehicle using jack stands.
3. Use a breaker bar and lug nut socket set to remove the wheel from the wheel hub assembly.
4. Disconnect the electrical connector from the ABS  (anti-lock braking system) sensor harness.
5. Remove the retaining bolt holding the sensor onto the steering knuckle. Also, remove any fasteners holding the sensor wiring harness in place.
6. Remove the sensor from the vehicle.
7. Ensure that the new sensor has the same design as the old sensor. Preferably, go for an OEM sensor.
8. Install the sensor, and fasten the retaining bolt. Also, reinstall the wheel speed sensor harness.
9. Using a torque wrench, tighten the fasteners and other parts to the specified torque values in the repair manual.
10. Reconnect the ABS sensor electrical connector.
11. Reinstall the brake rotor and caliper, and the brake pads if they were removed earlier.
12. Reinstall the wheel on the wheel hub, and remove the jack stands to lower your vehicle.
13. Reconnect the negative battery cable.
14. Finally, use a scan tool or code reader to clear any ABS codes or other Diagnostic Trouble Codes (DTCs).

How Much Does A Wheel Speed Sensor Replacement Cost?

Standard wheel speed sensor replacement parts can cost anywhere between $230 to $320, depending on your car’s model and the labor charges in your area. 

However, an ABS wheel speed sensor on a luxury vehicle can cost more. It could also be challenging for an auto parts mechanic to work around certain cars, further escalating labor costs. 

It’s also better to replace an old sensor with an OEM sensor, though it’s usually costlier than an aftermarket wheel sensor. 

Here’s why: 

• The exact clip placements and routing are crucial for a sensor’s functioning. 
• The air gap to the tone ring should be exact to read the speed data.
• The wheel speed sensor’s sensitivity depends on precise electrical specifications.

Is It OK to Drive With a Faulty Wheel Speed Sensor?

No, it’s not recommended to drive with a faulty wheel speed sensor, as it compromises key safety systems. The sensor feeds data to features like ABS, traction control, and stability control. 

When it fails, these systems are usually disabled, which can make braking less controlled and increase stopping distance, especially on wet or slippery roads. While the car will still run and may feel normal in dry, low-speed conditions, it can be risky during sudden stops or emergency maneuvers. It’s best to limit driving and get the sensor repaired as soon as possible.

What Causes a Bad Wheel Sensor?

Here’s what could be behind your faulty sensors:

• Dirt and debris buildup: Accumulated grime can impair the sensor’s ability to accurately measure wheel speed.
• Damaged wiring or connectors: Corrosion or physical wear in the wiring can disrupt signal transmission.
• Physical damage: Road debris, potholes, or incorrect installation can harm the sensor.
• Sensor wear: Prolonged use and exposure to harsh conditions can cause the sensor to deteriorate over time.

What Are the Symptoms of a Failing Wheel Speed Sensor?

From faulty brake pedals to ABS warning light, here are the five signs that indicate a bad ABS sensor: 

1. ABS Warning Light Turns On

Most modern vehicles are equipped with an ABS system, a traction control system, and an electronic stability system to ensure safer braking under different driving conditions. 

The ABS speed sensor (or ABS sensor) is a primary data source for these systems.

If a wheel speed sensor fails, the ABS light, Check Engine light, or the traction control light will illuminate on your vehicle’s dashboard. 

2. Anti-lock Brakes Stop Working

Your vehicle’s ABS control module relies on the speed sensor to detect wheel lockup during hard braking. 

The ABS module stops receiving this data when a wheel speed sensor fails. Without the speed signals, the ABS controller shuts down the anti-lock brake. 

3. Pulsating Brake Pedal

Each ABS wheel speed sensor measures the wheel’s speed it’s attached to. If a sensor goes bad, it’ll send false data to the ABS control module. This can cause the ABS module to believe that the vehicle is sliding off, and it’ll activate the anti-lock brakes.

When this happens, the ABS will release brake pressure, rapidly pumping the brakes. As a result, your brake pedal will pulsate when you hit it. 

4. Traction Control And Stability Control Stop Working

A failing wheel speed sensor will turn off your vehicle’s traction control, stability control, or any other driver assist feature. Sometimes, a damaged wire could also prevent the sensor from sending data to the control module.

As a result, you’ll find it difficult to maintain traction in poor weather conditions or have frequent braking issues.

If you’re facing issues with any of these features, you should get your ABS wheel sensor checked at an auto repair shop. 

5. Speedometer Doesn’t Work

This is a rare symptom and usually happens in older vehicles. If you notice your speedometer isn’t working, it could be a bad ABS sensor.

A faulty speedometer is also a safety hazard, as you won’t know whether you’re driving at a low speed or too fast, which could put your and others’ lives at risk.

3 FAQs on Wheel Speed Sensor

Here are answers to some common wheel speed sensor questions: 

1. What Is A Wheel Speed Sensor?

A wheel speed sensor (also known as an ABS sensor or ABS brake sensor) is a critical part of your braking system. The speed sensor, along with the tone wheel, monitors the speed of your vehicle’s wheels and relays the data to the ABS.

The ABS control module reads this data to ensure that all the wheels move at the same speed. Accordingly, it corrects any wheel and brings it to speed. With the help of wheel speed sensors, your car’s ABS can also prevent your wheels from locking up during hard braking.

Additionally, the speed sensors assist the traction control system in providing greater control over your vehicle on uneven roads.

However, like any other braking part, the wheel speed sensors are subject to wear and tear. They can be damaged by dust and dirt, often needing a replacement.

2. Where Is The Wheel Speed Sensor Located?

A speed sensor is usually located on the steering knuckle behind the wheel’s brake rotor. Sometimes it may also be installed directly on the wheel axle.

While most modern vehicles have four sensors (one on each wheel), an ABS system can also have other configurations:

• Two-channel four sensor ABS: An ABS brake sensor is located on each wheel, but the vehicle has one channel for the front sensors and one for the rear.
• Three-channel three sensor ABS: One sensor is located at each front wheel, and a rear wheel speed sensor is installed on the rear axle. The rear wheels are monitored together by the rear sensor, while the front wheels are monitored separately.
• Three-channel four sensor ABS: One sensor is installed on each wheel, but a single controller monitors the rear wheels.

3. How Long Does It Take To Replace A Wheel Speed Sensor?

Diagnosing sensor failure is pretty straightforward, and replacing it with a new sensor shouldn’t take more than an hour (including the diagnostic time).