An improved braking system called an ABS (Anti-lock Braking System) is a common feature in modern cars. The Engine Control Module of a vehicle receives information from a tachometer known as an anti-lock brake sensor, also known as an ABS sensor, about the rotational speed of a wheel (ECM).
The ABS sensor is sometimes referred to as the wheel speed sensor or ABS brake sensor. The ABS sensors communicate the speeds of all four wheels to the ECM, which uses this information to evaluate if the wheels are locking up since no two wheels rotate at the same speed.
The ABS wheel speed sensor serves a variety of purposes, making it an essential component of your car. This post discusses the symptoms, location, function, and cost to replace an ABS wheel speed sensor.
- 4 Bad ABS Wheel Speed Sensor Symptoms Illuminated Warning Lights
- Loss of Anti-lock Brakes
- Loss of Traction or Stability Control
- Pulsating Brake Pedal while Braking
- ABS Wheel Speed Sensor Location
- ABS Wheel Speed Sensor Function
- ABS Wheel Speed Sensor Replacement Cost
- How Long Does It Take To Replace ABS Sensor?
- ABS Sensor FAQs
Bad ABS Wheel Speed Sensor Symptoms Illuminated Warning Lights
There are many important lights on your vehicle’s dashboard that might warn you of potential hazards. One of the first signs of a defective ABS wheel speed sensor that you will likely notice right away as it fails is the ABS light.
Your car’s wheel speed sensor keeps track of the anti-lock braking system; if the sensor is damaged, disconnected, or has been smacked by debris, the ABS Light often illuminates, signaling that you need to replace the wheel speed sensor.
This light may also come on if there are further problems, such as a bad ABS pump, low brake fluid, problems with braking pressure, or air trapped in the brake lines.
The ABS light on your automobile alerts you when anything is wrong with the ABS system, similar to how the Check Engine Light does. As you turn the key, you’ll see this light briefly flash, but it’s usually a symptom that something is wrong with your ABS system if it stays on continuously throughout the trip. The ABS light will come on in the instance that an ABS sensor fails.
1. Loss of Anti-lock Brakes
The anti-lock brakes become unusable when an ABS wheel sensor fails. The system sends out a warning if a defect is discovered, and the ABS warning light turns on.
From this point on, the sensor’s vital data is no longer being transmitted to the vehicle’s electronic control module. This data is used by the computer to assess whether the wheels are locking up and need help. The ABS shuts down while the repair is being completed since the system is unsure of what is going on.
Imagine slamming on the brakes in response to a person crossing in front of your way; however, the brakes lock up, causing you to slide along with the vehicle. This is dangerous to both you and those around you. You run the risk of hurting both yourself and a passing pedestrian.
Therefore, anytime there is a defective speed sensor, it implies that the system is not functioning properly, and this problem has to be fixed as soon as possible.
2. Loss of Traction or Stability Control
Other features include stability control, traction control, roll stability, and hill-start aid may also be lost along anti-lock brakes. The computer also turns off these systems when the sensor stops transmitting data.
The ABS wheel speed sensor is essential for the effective operation of many different parts of your automobile, not only the antilock brakes. Data from the ABS sensor may also be used by the stability and/or traction control systems for stability control, hill-start assistance, and a number of other purposes.
Those systems may be prevented from functioning by a defective ABS wheel speed sensor, and they will be inoperative unless a new sensor is installed.
3. Pulsating Brake Pedal while Braking
Pulsating brake pedals are another sign of a malfunctioning ABS sensor on our list. It is possible to deceive your car’s ABS control module into engaging even when you apply the tiniest amount of pressure to the brake pedal if one or more speed sensors have failed.
It will immediately trigger and engage the traction control and anti-brake lock systems, forcing the automobile to stop with extreme force without cause. Therefore, when you step on the brakes, you will get that pulsing sensation.
When these systems are turned on, there will also be sounds coming from the rotors themselves. Which, in fact, sounds awful. It will appear to you that nothing is going well. However, it’s not always the case. The crucial step is to take note of this activity and deal with the problem appropriately.
ABS Wheel Speed Sensor Location
Although some are mounted directly on the axle, the ABS wheel speed sensor is typically found at the wheel, behind the brake rotor. There are various numbers of ABS wheel speed sensors in every car.
Each wheel will have a speed sensor behind the rotor if the system has four ABS wheel speed sensors. In systems with three sensors, one is placed on the back axle in place of the wheel, and two sensors are placed at each front wheel.
The number of sensors in the car depends on the ABS type. Here are four different ABS setups:
1. Two-channel, four-sensor ABS
ABS with two channels and four sensors has one sensor on each wheel and two channels—one for the front and one for the back. ABS activates at a specific location on the car if any speed sensors identify a wheel lockup.
2. Three-channel, three-sensor ABS
ABS with three channels and three sensors is equipped with one at each front wheel and one on the rear axle. The front wheels are analyzed individually, while the rear wheels are simultaneously monitored.
3. Three-channel, four-sensor ABS
ABS with three channels and four sensors operates with one controller for the back wheels despite having sensors at each one.
4. Four-sensor ABS
Each wheel has a separate sensor that is monitored. Modern automobiles most frequently have this setup.
ABS Wheel Speed Sensor Function
The ABS wheel speed sensor is sometimes known as an ABS brake sensor or more simply, an ABS sensor. Regardless of the name it goes by, it is a vital component of the ABS.
Most modern cars include an anti-lock braking system (ABS). To gauge the rotational speed of the wheels, ABS wheel sensors are fastened to the wheels or the axle. A magnet and toothed ring encased in a coil is typically found within ABS sensors. The signal that is delivered to the ABS controller is produced when the magnet and ring make contact and an electric field is produced.
The controller then decides how fast each wheel or axle should go. The Engine Control Module then receives this information (ECM). The ABS is turned on when the ECM detects that a wheel is locking up. It runs so quickly that it commonly produces a grinding sound and pulsing sensation.
The traction control system and the ABS sensor work together to regulate how the vehicle moves under shaky conditions. The mechanism will activate when one tire starts moving faster than the others when traction is lost.
Problems result from the computer decreasing the amount of braking force given to the wheel. When the force is reduced the wheel may once again rotate properly and restore its grip. Modern vehicles also include stability control systems that are controlled by the same sensors.
ABS Wheel Speed Sensor Replacement Cost
Wheel rotation rates are tracked by ABS speed sensors, which alert the computer controlling the system to alter brake pressure if a wheel locks up during braking. There is one sensor for each wheel in the four-channel system used by the majority of modern automobiles.
Your ABS system won’t work if even one ABS speed sensor malfunctions. In an emergency, if you have to brake forcefully, your brakes will lock and you won’t be able to steer your automobile away from another car or object. It may come down to life or death here.
This is the reason why a failing ABS speed sensor needs to be changed right away. Your technician will run a diagnostic test during an inspection to identify the failing sensor or sensors and whether they need to be replaced. A professional can remove your car’s tires and replace your ABS speed sensor if one of the sensors in your ABS system breaks.
Depending on the vehicle model and labor expenses, the cost to repair an ABS wheel speed sensor typically ranges from $200 to $400 per sensor. The wheel speed sensor will cost you between $100 and $150, and the labor will cost you between $100 and $300.
Luxury cars usually include more expensive ABS wheel speed sensors, and some models might be more difficult to repair, which drives up labor costs.
With a few tools, however, you can easily replace the ABS wheel speed sensor on your own. This can be a project worth taking on in your garage if you have some basic mechanical expertise. However, they might get stuck after a time, so you might need a heat source to get them out
What Happens If You Don’t Fix ABS Sensor?
One may safely assume that many drivers typically prioritize mechanical problems on their vehicles according to a variety of factors, including the cost to fix or replace. Many people believe that as long as the car doesn’t break down, a broken sensor or a dashboard warning light may be fixed later on.
However, a seemingly unimportant error with wheel speed sensors might become a significant safety concern. Because of this, it is often dangerous to operate a vehicle with a damaged wheel speed sensor.
In the case when the wheel speed sensor isn’t operating as it should, it won’t send any information to the ECU during a problem. You risk losing control of your car and crashing because the ABS system won’t know when to begin working.
The entire system is rendered unusable when the sensor is damaged since it is dependent on accurate data to operate. Even safety features like traction control and electronic stability control may be compromised by a failed ABS system.
Tip: Driving while you know your ABS system isn’t functioning is incredibly dangerous. You may be held more accountable for the harm if you caused an accident while being aware of the failing sensor.
Mechanics will record any evident faults in the system as part of their invoice during mechanical inspections or basic oil and filter replacement services. Hence, the wheel speed sensor is best changed as quickly as possible if any mechanic tells you that it is damaged.
How Long Does It Take To Replace ABS Sensor?
It is best to get a faulty ABS sensor replaced as soon as possible. The sensor has to be cleaned with a metallic brush first before being replaced. The new ABS sensor may then be installed, and the sensor wire should be properly placed.
The replacement of the ABS sensor is rather quick and easy, and it should only take 10 minutes for mechanics or car owners who are skilled. Allow an experienced mechanic to replace the ABS sensor in your automobile to ensure it is done correctly.
ABS Sensor FAQs
How to tell which ABS sensor is bad?
By using an OBD2 tool to scan your vehicle, you may find out whether any of the sensors are failing and whether or not this is the case. Your automobile will issue an error if a sensor is broken and will identify the particular component that is damaged.
How to test ABS sensor?
A multimeter tool can be used to test this component. To find out if this tool has resistance and if it generates a voltage when the wheel is rotating, you must bench test it. Before you can test this component, you must first understand the way a multimeter works.
Can you drive with a bad ABS sensor?
Your car’s anti-lock braking system (ABS) won’t function correctly if your ABS sensor is broken. Although it’s not advised, it is possible to drive with a damaged ABS sensor. Driving should always be done with safety in mind, therefore if you have a defective ABS sensor, it’s better to get it replaced right away.
Can ABS sensors be cleaned?
Although it’s possible, it’s quite doubtful that cleaning the ABS sensor would fix the issue. ABS sensor failure is typically caused by electrical issues and open circuits. The ABS relator ring, on the other hand, might result in the sensor giving the wrong readings if it is excessively rusted.
What causes ABS sensors to go bad?
Several factors can lead to the failure of ABS sensors. One is the buildup of dirt and debris on the sensor or in the connector. The sensor is installed in a relatively exposed location, which makes this possible over time, especially if you stay in a place with a lot of dust or dirt.
Corrosion is another potential outcome that may happen if water enters the system. Last but not least, the sensor itself may suffer physical damage and cause it to fail.
Does the ABS sensor affect acceleration?
Though extremely rare, it is not impossible. The traction control system uses the same ABS sensors, and as a safety measure, it can restrict engine power if a wheel reports the incorrect wheel speed.
The wheel speed sensor will not be able to provide any information to the ECU if it finds itself to be unable to function properly in certain situations. Because the ABS system won’t know when to start operating, you run the danger of losing control of your vehicle and getting into an accident.
When the sensor is broken, the entire system is rendered useless because it depends on proper information to function. For this reason, it is recommended to have a damaged ABS sensor replaced as soon as possible.