The ABS wheel speed sensor has multiple functions, making it an important part of your car. When one starts failing, you may notice a number of symptoms.
This article looks at the symptoms, location, function and cost of replacing a faulty ABS wheel speed sensor. Let's take a quick look at the signs you can expect.
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Symptoms of a bad ABS wheel speed sensor
The most common symptoms of a bad ABS sensor are an ABS warning light on the dash, a pulsing brake pedal, a loss of ABS brakes, or a loss of traction control. You may also notice other warning lights on the dashboard, such as:Check the engine lightor traction control light.
As you can see, there really aren't many ways to tell if an ABS sensor is faulty. This is mainly because the ABS control module turns on the ABS warning light and disables the system to avoid accidents.
Here is a more detailed list of signs of a bad or faulty ABS wheel speed sensor to look for:
1. Illuminated warning lights
Your dashboard contains a variety of important lights that warn you of danger. When the ABS wheel speed sensor fails, the ABS light is likely one of the first signs of all the symptoms of a bad ABS wheel speed sensor.
At first, it can simply cause the ABS warning light to come on. However, if the other systems are no longer working properly, you can see that tooTraction and stability control warning lights.
In rare cases, faulty ABS wheel speed sensors can cause the speedometer to stop registering.
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2.Brake pedal pulsates when braking
The ABS sensors measure the speeds of each wheel, and if one of the ABS sensors is faulty, it will read the wrong speed on one or more wheels. This tricks the ABS control module into thinking the car is skidding on a slippery surface.
This activates the ABS and traction control, and you'll feel it if you feel a pulsing sensation under braking or press the brake pedal.
3.Loss of anti-lock braking system
When an ABS wheel sensor fails, it renders the anti-lock braking system inoperable. If a fault is detected, the system will issue a warning and the ABS warning light will illuminate.
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 and need assistance.
Since the system does not know what is going on, the ABS will shut down until the repair is complete.
4. Loss of traction or stability control
Not only can you lose the anti-lock braking system, but you can also lose other features such as stability control, traction control, roll stability and hill-start assist. When the sensor stops sending information, the computer shuts down those systems as well.
However, problems can arise even if the ABS light is not lit. If you're struggling to maintain traction in inclement weather or notice drivability issues when braking quickly, the ABS wheel speed sensor could be the culprit.
It can also be caused by faulty wire connections running from the sensor to the ECM.
Position des ABS-Raddrehzahlsensors
The ABS wheel speed sensor is located on the wheel behind theBremsrotor, but some are placed directly on the shaft. Each vehicle contains a different number of ABS wheel speed sensors.
If the system includes four ABS wheel speed sensors, there will be one at each wheel behind the rotor. Systems with three sensors have one on each front wheel and one on the rear axle instead of either rear wheel.
The ABS type determines how many sensors the vehicle contains. Here are four ABS settings.
ABS with two channels and four sensors: There is one sensor on each wheel, but there is one channel in the front and one in the back. If a speed sensor detects a locked wheel, ABS will activate in that part of the vehicle.
ABS with three channels and three sensors: There is one sensor on each front wheel and one on the rear axle. While the rear wheels are monitored at the same time, the front wheels are evaluated separately.
ABS with three channels and four sensors: while there are sensors on all wheels, the rear wheels work on one controller.
Four-sensor ABS: There is a sensor on each wheel that is monitored separately. This is the most common configuration on modern vehicles.
Function of the ABS wheel speed sensor
ÖABS-RaddrehzahlsensorIt can also be called ABS brake sensor or simply ABS sensor. Whatever it is called, it is a critical part of ABS.
The anti-lock braking system (ABS) can be found in most new cars.ABS wheel sensorsare attached to the wheels or to the axleCalculate the rotational speed of the wheels. Most ABS sensors contain a ring gear and a magnet wrapped around a coil. The contact between the magnet and the ring creates an electric field that is converted into the signal that is sent to the ABS controller.
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From here the controller determines the speed of each wheel or axle. This information is then sent to the Engine Control Module (ECM).
If the ECM detects that a wheel is locking, the ABS will activate. It works at such a high speed that it often produces a grinding noise with a pulsating feel.
If the vehicle is also equipped with traction control, the ABS sensor will help control vehicle movement in tricky situations. When traction is lost, one wheel's speed differs from the others, triggering the system.
The computer reduces the braking force applied to the wheel, causing problems. When this force subsides, the wheel can regain grip and spin normally again. The same sensors also control the stability control systems in modern cars.
RELATED:Symptoms of a bad ABS control module
ABS wheel speed sensor replacement cost
The average cost of replacing an ABS wheel speed sensor ranges from $200 to $400 per sensor depending on vehicle model and labor costs. You can expect to pay around $100-$150 for the wheel speed sensor and another $100-$300 for the labor.
ABS wheel speed sensors on luxury vehicles can often cost more, and some models can be more difficult to work with, increasing labor costs.
However, it is not difficult to replace the ABS wheel speed sensor yourself with just a few tools. If you have basic mechanical knowledge, this may be a project worth doing in your home garage. They can get stuck after a while, so you may need a heat source to remove them.
Testing the ABS wheel speed sensor
frequently asked questions
Can you drive with a defective ABS sensor?
If your ABS sensor is defective, it means that your car's anti-lock braking system (ABS) is not working properly. You can technically drive with a bad ABS sensor, but it's not recommended. Safety should always come first when driving. So if you have a bad ABS sensor, it's best to have it repaired as soon as possible.
Can ABS sensors be cleaned?
You can try cleaning the ABS sensor, but that probably won't fix the problem. Electrical problems and open circuits are the most common reasons for ABS sensor failure. However, if the ABS resistance ring is badly rusted, it can give the sensor incorrect readings.
What Causes ABS Sensors to Go Bad?
There are a few things that can cause ABS sensors to go bad. One is the accumulation of dirt and debris on the sensor or connector. This can happen over time as the sensor is mounted in a very exposed location, especially if you live in an area with a lot of dust or dirt. Another possibility is corrosion, which can occur when water enters the system. Finally, physical damage to the sensor itself can also lead to failure.
Does the ABS sensor affect acceleration?
Although it's quite unlikely, it's not impossible. ABS sensors are also used for the traction control system and if a wheel is reading the wrong speed it can reduce engine power as a safety feature.
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If your car is exhibiting any of the above ABS sensor symptoms but you feel like you lack the knowledge to properly diagnose it, it's time to take it to a mechanic.
Due to the fact that the ABS sensors are installed in an area exposed to water and dust, removing the old sensor can be difficult and if you are unaware you may need the help of an experienced mechanic.
However, if you have good experience in handling cars, you can replace the sensor yourself. Replacing an ABS sensor is usually not very expensive, but the exact cost will depend on the make and model of your car.
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FAQs
How much does it cost to replace ABS wheel speed sensor? ›
$62-$78. The average cost to replace your Wheel Speed Sensor is $62 - $78. Pricing may vary based on the type of car you have, as well as the type of (and quality) auto shop that you go to.
How much does it cost to replace ABS sensor? ›The cost to replace an ABS sensor can vary depending on the car you drive—but you can expect to pay between $100 and $150, plus an extra $100 to $300 in labor costs.
What are the symptoms of a faulty ABS system? ›- THE DASHBOARD'S ABS LIGHT IS ON. When your ABS experiences a mechanical issue, your dashboard's ABS light will illuminate as a warning. ...
- YOUR BRAKE PEDAL LOCKS UP. ...
- INCORRECT SPEEDOMETER READINGS. ...
- BRAKING SYSTEM IS UNRESPONSIVE.
If your ABS sensor goes bad, can you still drive your car? The answer is yes, but it's not ideal. ABS sensors are important for keeping your car stable and stopping properly in difficult conditions.
Can I drive my car with a broken wheel speed sensor? ›However, when it comes to wheel speed sensors, a minor-seeming glitch may turn into a major safety risk. That is why in general, it is unsafe to drive a vehicle with a broken wheel speed sensor.
What happens when your wheel speed sensor goes out? ›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.
What problems can a bad ABS sensor cause? ›Defective ABS wheel speed sensors might cause the speedometer to cease registering in rare situations. 2. Pulsating Brake Pedal - While braking, the ABS sensors detect the speeds of each wheel, and if one of the ABS sensors fails, it will read the incorrect speed on one or more wheels.
What happens when speed sensor goes out? ›When there's no speed signal coming from the sensors, shifting of gears will be a problem because the powertrain control module won't control them correctly. This will make the transmission not work properly. It will either shift more quickly or roughly than expected.
Can Autozone check ABS sensors? ›It Might Be the ABS
Unfortunately, the only way to check whether or not the problem is with the ABS is to go and get the codes of your car read. AutoZone can scan your codes as part of our Fix Finder service, or you can do it yourself if you already have a scan tool.
If the ABS speed sensor fails or does not work properly, you can replace it on your own.
How long do ABS wheel speed sensors last? ›
You can usually expect to get 30,000 to 50,000 miles out of your ABS speed sensor – more if you don't drive often, or if you live in an area where your car is seldom exposed to dirt, road salt, or other compounds that can cause damage to electronics.
What is the most common problem with ABS systems? ›The most common ABS problems occur when sensors become contaminated with debris or metal shavings. Malfunctions also occur when sensor wiring becomes damaged, resulting in intermittent or no continuity.
What happens when the ABS module goes out? ›The Brakes Lock Up
So, when an ABS control module fails, you'll likely notice it when applying more braking pressure. A bad ABS module can behave erratically, making your brakes lock up even under normal braking. You might even notice unusual behavior from the brakes, like random clicking noises.
Lift the vehicle with a car jack, disconnect the ABS from its sensor cable, set the multimeter to the 20k Ohms range, and place the probes on the sensor terminals. You expect to get the appropriate reading between 800 and 2000 Ohms if the ABS is in good condition.
What happens if I unplug my ABS sensor? ›Removing a wheel speed sensor will disable ABS—and sometimes, stability control. If your car has a yaw sensor, you can unplug that for results. You can also try simply unplugging the ABS module, though that could adversely affect your car's braking performance.
Is there a fuse for the ABS sensor? ›The fuse box for the ABS is located in the engine compartment on the passenger's side. To open it, push the tab as shown. 253 to 256, or the diagram on the fuse box lid, which fuse or fuses control that component.
How much does it cost to fix ABS and traction control? ›From $1,500 to $3,000 is the usual pricing range. There is a wide range in the cost of control modules from vehicle to vehicle. A replacement control module will typically cost you around $1,000. Usually, one might expect to pay between $800 and $2000.
Will a wheel speed sensor throw a code? ›The inspection process is typically fairly simple, but even relatively small issues with the wiring and connections for the wheel speed sensors can impact the connection, causing the system to throw a C0035 code.
Will a wheel speed sensor throw a check engine light? ›Common signs include harsh or improper shifting, cruise control not working, and the Check Engine Light coming on.
What is the difference between a vehicle speed sensor and a wheel speed sensor? ›A vehicle speed sensor (VSS) is a small component mounted on your car's transmission that lets the car's onboard computer know how fast you're moving. It's also known as a wheel speed sensor, transmission speed sensor, or output shaft speed sensor.
Is wheel speed sensor same as ABS sensor? ›
Wheel speed sensors are often also called ABS sensors as they were used in vehicles for the first time when ABS was introduced. Wheel speed sensors can be designed as active or passive sensors, depending on how they operate.
How many ABS wheel speed sensors are on a car? ›Modern vehicles have four wheel speed sensors—one for each wheel of your car.
What are the signs of a bad traction control module? ›Common signs include the Traction Control System (TCS) Light coming on, TCS not turning off/on, and loss of TCS or ABS features.
How much does it cost to replace a vehicle speed sensor? ›The national average cost for a vehicle speed sensor replacement in 2023 is $85.
How often do wheel speed sensors go out? ›It will cost between $200 and $400 to replace an individual speed sensor, and there is one for each wheel. Typically, they should be replaced every 30,000 to 50,000 miles.
Will disconnecting battery reset ABS light? ›Resetting Your ABS Dashboard Warning Light
Step One: Disconnect the positive cable from your car battery. Then, hold down the brake pedal to drain the vehicle's electrical system. This will result in a reset of the car's central computer.
Free Fix Finder Service from AutoZone
Fix Finder reads Check Engine, ABS, and maintenance lights. The free test takes less than a minute and you'll get an easy to understand report printed and emailed.
The average cost for an Anti-lock Brake System (ABS) Diagnosis is between $82 and $104. Labor costs are estimated between $82 and $104.
How long does it take to replace ABS sensor? ›For mechanics, or for handy car owners, the ABS sensor replacement is relatively quick and simple and should take about ten minutes. To make sure the ABS sensor in your car is correctly changed, let a qualified mechanic do it for you.
Do I need to disconnect battery to change ABS sensor? ›Disconnect Negative Battery Terminal
As when working on all electrical parts within your car, the first step is to ensure that you disconnect your batteries negative terminal. Simply disconnect the nut that holds this in place before sliding the clamp to cut off power to all the ABS sensors.
How long does it take to install a wheel speed sensor? ›
Fortunately, it is easy to replace a wheel speed sensor and takes you about an hour at maximum. You can also remove the ABS wheel speed sensors separately keeping other parts integrated into the wheel bearing hub assembly.
Why does my ABS and traction light keep coming on? ›If the brake system is malfunctioning, the traction control light might come on as a result. The light for your ABS might also come on if the brake fluid is low. Your car likely has sensors in those tanks in order to detect when fluids are low, which could be dangerous.
Do you still have normal brake functions if your ABS is not working? ›Without ABS you still have normal brake functions. Drive and brake as you always have. Vehicles with ABS have yellow malfunction lamps to tell you if something isn't working.
What happens if you don't fix ABS module? ›You can still drive without a functional ABS control module, as long as there's no problem with your conventional brake system. However, take extra care, especially in wet or slick conditions, as the brakes' anti-lock element won't work, and you likely won't have steering control if your tires lock up.
How much do ABS modules cost? ›The national average cost for abs control module replacement in 2023 is $493
What happens when an ABS sensor fails? ›Common signs include the ABS Light coming on, decreased stopping time, and less stability under icy or wet driving conditions.
Is wheel speed sensor and ABS sensor the same thing? ›Wheel speed sensors are often also called ABS sensors as they were used in vehicles for the first time when ABS was introduced. Wheel speed sensors can be designed as active or passive sensors, depending on how they operate.
What causes ABS speed sensor failure? ›Why do ABS sensors fail? Given its position, the reluctor wheel or tone ring can easily become dirty or damaged. Similarly, dust can collect on the sensor. Both could result in an erratic, or even no signal at all.
Can AutoZone check ABS sensors? ›It Might Be the ABS
Unfortunately, the only way to check whether or not the problem is with the ABS is to go and get the codes of your car read. AutoZone can scan your codes as part of our Fix Finder service, or you can do it yourself if you already have a scan tool.
When there's no speed signal coming from the sensors, shifting of gears will be a problem because the powertrain control module won't control them correctly. This will make the transmission not work properly. It will either shift more quickly or roughly than expected.
How do I know if I need a new wheel speed sensor? ›
Common signs include the ABS Light coming on, ABS not working properly, and the Traction Control Light staying on.