The ABS wheel speed sensor has multiple functions, making it a vital part of your automobile. When one begins to fail, you might notice several symptoms.
This article reviews the top for symptoms of a bad ABS wheel speed sensor, its location, function, and replacement cost. Let’s take a quick look at what signs you can expect.
The most common symptom of a bad ABS sensor is an ABS warning light showing up on your dashboard. You may also notice issues like a pulsating brake pedal while braking or a complete loss of the anti-lock brake system.
As you can see, there are actually not that many ways to tell if an ABS sensor has gone bad. This is mainly because the ABS control module will light up the ABS warning light and deactivate the system to prevent accidents. Here is a more detailed list of the most common symptoms of a bad ABS wheel speed sensor.
Bad ABS Wheel Speed Sensor Symptoms
1. Illuminated Warning Lights
Your dashboard contains a variety of important lights that alert you to danger. When the ABS wheel speed sensor fails, the ABS light is probably one of the first sign your will notice of all bad ABS wheel speed sensor symptoms.
At first, it might simply cause the ABS warning light to come on. However, when the other systems stop functioning properly, you might also see the traction and stability control warning lights.
In rare cases, defective ABS wheel speed sensors can cause the speedometer to stop registering.
RELATED: What does the ABS light mean & What Causes it?
2. Pulsating Brake Pedal while braking
The ABS sensors measure the speeds of each wheel, and if one of the ABS sensors has gone bad, it will read the wrong speed on one or more wheels. This will cause the ABS control module to get tricked and thinking the car is sliding on a slippery surface.
This will cause the ABS and traction control to kick in, and you will feel it by feeling a pulsating or pumping brake pedal while braking.
3. Loss of Anti-lock Brakes
When an ABS wheel sensor fails, it causes the anti-lock brakes to be inoperable. Anytime a fault is noticed, the system triggers an alert, and the ABS warning light comes on.
From here, the vehicle’s electronic control module stops receiving valuable data from the sensor. The computer relies on this information to determine if the wheels are locking up and require support.
Because the system doesn’t know what is happening, the ABS shuts down until the repair is made.
4. Loss of Traction or Stability Control
Not only can you lose anti-lock brakes, but also other functions, such as stability control, traction control, roll stability, and hill-start assist. When the sensor stops sending information, the computer shuts down these systems as well.
However, you can experience problems even when the ABS light isn’t on. If you struggle to maintain traction in poor weather conditions or notice handling issues when you brake quickly, the ABS wheel speed sensor might be to blame.
It could also be caused by damaged wiring connections running from the sensor to the ECM.
ABS Wheel Speed Sensor Location
The ABS wheel speed sensor is located at the wheel, behind the brake rotor, but some are placed directly on the axle. Each vehicle contains a varying amount of ABS wheel speed sensors.
If the system contains four ABS wheel speed sensors, there will be one at each wheel behind the rotor. Systems with three sensors have two at each front wheel and another on the rear axle instead of at the wheel.
The ABS type determines how many sensors the vehicle contains. Here are four ABS configurations.
Two-channel, four-sensor ABS: One sensor is located on each wheel, but there’s a channel in the front and one for the rear. When any speed sensors detect a wheel lockup, ABS engages at that part of the vehicle.
Three-channel, three-sensor ABS: There is one sensor located at each front wheel and one located on the rear axle. While the rear wheels are monitored at the same time, the front wheels are evaluated separately.
Three-channel, four-sensor ABS: While there are sensors located at every wheel, the rear wheels run on one controller.
Four-sensor ABS: One sensor is located at each wheel and monitored separately. This is the most common configuration with modern vehicles.
ABS Wheel Speed Sensor Function
The ABS wheel speed sensor can also be called an ABS brake sensor or, more plainly, an ABS sensor. Whatever it is called, it is a critical part of the ABS.
The anti-lock braking system (ABS) is found on most new vehicles. ABS wheel sensors are attached to wheels or the axle to measure the rotation speed of the wheels. Most ABS sensors contain a toothed ring and magnet that’s enclosed with a coil. Contact between the magnet and ring creates an electric field, which turns into the signal that is sent to the ABS controller.
RELATED: 4 Symptoms of a Bad ABS Ring
From here, the controller determines the speed of each wheel or axle. This information is then transmitted to the Engine Control Module (ECM).
When the ECM sees that a wheel is locking up, the ABS is activated. It operates at such a fast speed that it often creates a grinding noise with a pulsating sensation.
If the vehicle is also equipped with traction control, the ABS sensor helps control the movement of the vehicle in precarious situations. When traction is lost, the speed of one wheel will be different than the others, causing the system to kick in.
The computer reduces the amount of braking force being applied to the wheel, causing trouble. When this force decreases, it allows the wheel to regain grip and rotate normally again. These same sensors run the stability control systems in modern cars as well.
RELATED: Symptoms of a Bad ABS Control Module
ABS Wheel Speed Sensor Replacement Cost
The average ABS wheel speed sensor replacement cost is between $200 and $400 per sensor, depending on the car model and labor costs. You can expect to pay about $100 to $150 for the wheel speed sensor and another $100 to $300 for the labor.
ABS wheel speed sensors on luxury vehicles can often cost more, plus some models can be harder to work on, which increases the labor cost.
However, it’s not difficult to replace the ABS wheel speed sensor yourself with a few tools. If you have basic mechanical knowledge, this might be a project worth tackling in your home garage. They can become stuck after a while though, so you may need some heat source to remove them.
Ochei Paul
Hi, Am having the ABS, Brake, VSC and 4WD light coming up on the dashboard after some days it goes off on my 2011 Toyota RAV4 only had it for 15 months now. And also during braking i get this Pulsation while braking.I equally noticed the front left wheel gets so hot after driving around for a while i guess the brake pads are binding. Could this be as a result of faulty ABS sensors?
Beth Kern
Hi, I have a 2007 Camry and about 6 months ago had my brake pads and calipers replaced. Shortly after I started getting a weird stuttering under the brake pedal. My mechanic cannot seem to pinpoint it but believes it is antilock sensor but since I have four, one for each wheel, this is causing a delay in repairs. My ABS light is not coming on. The grinding/slipping comes and goes and even on occasion even occurs when backing up. Do you think the ABS sensors could be the cause or do you have another suggestion? (I have taken my car in on 3 different occasions and cannot get it to act up while in the shop.)
Magnus Sellén
If it's fast pulsating even when driving at lower speeds, it's definitely an issue with the ABS system. Need to check the distance between the ABS sensors and tone rings, as well as check the sensor wirings. However, if it's pulsating at higher speeds when braking hard it could be the rotors. Difficult to pinpoint without test driving yourself.
DeeJai Jones
I have a question. I just changed both my front wheel bearing and both of the ABS wheel sensors on my 2009 Ford Focus SEL but my ABS and traction control light is still coming on. What could be the issue if I have just changed both sides.
Magnus Sellén
You need to check the wirings. Especially where the wire is bending when you turn your wheels! If there is a trouble code on the front ABS sensors - electric circuit fault
Asllan Hafuzi
Hi I have a Toyota Prius v 2026, when I drive in the bad road first tern ABS lamp on after all the lamps and it's not possible to drive
Tony
I have a ef falcon theirs a noise coming from the front left wheel I have replaced the disc pads bearing the only thing I havernt replaced is abs sensor it sounds a bit like a bearing but more of of a wind left front if you could help would appreciate it cheers
Felix
Does removing the front tire of 2016 Toyota venza affect the ABS. I REMOVED MY FRONT TIRE OF MY VENZA AND AFTER FIXING THE TIRE BACK, MULTIPLE. DASH BOARD LIGHT HAVE PERSOSTED WITHOUT GOING OF, eg, traction, airbag, Abs, AWD indicators etc. In total about 7 dash board lights have remained on just after removing and fixing on from tire.
G Keir
Hi, I have had to send my 1 year old giulietta to the garage due to loud hissing/ air leak sound when the car is stationary and the brakes are pumped. The garage has found a faulty ABS sensor. Is this one of the symptoms? The ABS sensor light didn’t come on while this was happening? Any advice would be appreciated, thanks.
Ian Robinson
Hi, I have had a problem with my 2007 Holden Captiva, sometimes (but not always) when braking there is a "shudder" feeling that comes through the brake pedal which also makes a slight "grinding" noise. I have taken it to several mechanics, have had sensors & module replaced (costing approx $2000) but problem still exists. The issue is that the shudder/grinding does not always occur which makes diagnosis a problem. Your thought ? Ian
Mick
I have just put all new brakes, rotors and calibers on my equinox s as nd still when I hit the brakes there is a loud noise on right front? No one including mechanic can tell us why
Millicent
Thanks for the article. Very informative.. when the slip indicator sign shows what does that mean. I drive a 2013 Toyota avalon. Thanks
Rich
Sounds like your caliper has slack… so when you push on pedal the piston takes up the slack and makes the noise of piston hitting pads hitting rotor. Check out caliper…
Eddie Maynard
Does a ABS sensor cause the front caliper on passenger side to stick
Joe
No, it will most likely be a failed seal and corrosion on the piston within the calliper body.
Moses
Thank you so much. The article is very helpful. Sir, could you elaborate to me the use of a multimeter to test the sensor. I' m slightly confused on the following sentence "Allow the voltage to fluctuate and then drop to zero". Thank you once again for your help.