While you are driving, your vehicle constantly monitors sensors throughout the car to ensure everything works as intended. One of the systems being monitored is the ABS, which stands for the anti-lock braking system. Your ABS light comes on when something goes bad with your antilock system. This article mainly explains the ABS light meaning, its causes, and how to fix illuminated ABS light.
What does the ABS Light Mean?
ABS stands for the antilock braking system. The illuminated ABS light in your car’s gauge cluster indicates that your antilock system has been deactivated because of a malfunction.
The ABS uses sensors at each wheel to monitor their rotational speed. A computer monitors the signals from all four wheels and the position of the brake pedal to ensure the vehicle is stable and under control.
If the computer notices any abnormal signals or the lack of a signal from any of the sensors, it will turn the ABS warning light on to alert the driver of an issue. In addition to monitoring the wheel speed sensors, the computer can turn the ABS light on for other reasons, like low brake fluid levels or a blown fuse.
Some ABS systems may flash the light a few times and then leave it on constantly. The number of flashes refers to a trouble code and can help you identify the issue. Refer to the vehicle repair guide or online information to determine what your ABS system tells you when it flashes.
What does ABS Mean?
“ABS” stands for the anti-lock braking system. When you press the brake pedal, you are likely to lose traction on one or more tires. This is called lock-up. Tire lock-up happens when the brake pad and brake rotor friction is greater than the friction between the tire and the road surface.
An ABS is designed to prevent you from “locking” up your brakes or applying so much pressure to your brakes that the axle and your wheels themselves stop turning completely.
The ABS is a safety system that has the ability to recognize a stop in the rotation of the wheels during braking while the car is still in motion and release the brake fluid pressure which allows the wheels to start rotating again.
The system is capable of this because it is fully automated. This operation may sound simple at first but its importance lies in the controlled stoppage or slowdown of the vehicle while greatly reducing the chances of losing control of the car.
This will allow the car wheels to avoid getting locked up and skidding uncontrollably. But a vehicle’s ABS is also prone to wear and tear and can fail. If you see the ABS light come on, the best course of action is to resolve the issue as soon as possible.
What causes the ABS Light to come on?
The ABS light comes on due to one or more of the below-given causes:
- Low Brake Fluid
- A blown fuse
- Bad Speed Sensor
- Bad Hydraulic Pump
- Bulb Check
- Bad ABS Module
- Bad Steering Rack
- Faulty Steering Angle Sensor
- PCM Issues
- Limp Mode
1) Low Brake Fluid
The ABS light on the dashboard is a sign that either the brake fluid escaped from the system through a leak or evaporation or that the fluid level dropped but wasn’t picked up by the sensor. If the brake fluid level drops and the ABS light comes on and off, then the sensor needs replacing as it’s defective.
The ABS fluid level sensor is vital to the overall functioning of the anti-lock braking system; a failure can affect the rest of the system. Therefore, if you suspect the fluid level sensor is faulty or the ABS light came on, then make a thorough vehicle diagnosis or contact an expert mechanic to find out if the ABS fluid level sensor needs a replacement or if there is a different issue to be addressed.
2) A Blown Fuse
ABS fuse functions like other electrical systems. The fuse protects the ABS and can blow if there is an electrical surge. Check the fuse; if it’s blown, replace it with a new fuse. If the fuse blows again, then there is a short circuit in the ABS; check the pump motor or ABS computer.
The fuse is found in the fuse panel underneath the dashboard or under the hood in the power distribution center.
3) Bad Speed Sensor
Wheel speed sensors are a piece of equipment that tells your computer how fast each wheel is turning independently. If the computer detects an anomaly in these speeds, then your traction control system makes adjustments or shifts power to different wheels to compensate.
However, if a speed sensor is dirty or stops working, then it can’t relay this information accurately. Rather than make a load of adjustments, it will usually disable your ABS and/or traction control systems until you either restart your vehicle or resolve the problem.
Read More: Bad Wheel Speed Sensor Symptoms and Causes
4) Bad Hydraulic Pump
If one wheel of your vehicle moves at a different speed than the other wheels, the wheel speed sensor detects this and then notifies the anti-lock braking system.
Once this happens, the system will activate the hydraulic pump to increase the amount of brake fluid pressure. This will allow the wheels to maintain traction as they touch the ground.
Unfortunately, hydraulic pumps tend to get worn out after years of using them. This would certainly cause the ABS light to come on, meaning you’d need to replace the pump immediately.
Read More: Symptoms and Causes of Bad Hydraulic Pump
5) Bulb Check
Some vehicles will perform what is known as a bulb check on the dashboard. This check is for the driver’s convenience, so they know the bulbs of their vehicle’s warning lights are working properly.
These lights will usually turn off by themselves after a certain amount of time. In some instances, there may be a glitch in the bulb check, which keeps the ABS warning light illuminated after the bulb check is completed.
6) Bad ABS Module
The module of the anti-lock braking system can form corrosion after a while. This is one of the most common reasons why there is a problem with the anti-lock braking system.
If the module is corroded, then it can’t obtain information from the wheel speed sensor. As a result, the ABS light illuminates on the dashboard. It doesn’t even take a lot of corrosion to cause this to happen, either. But you will need to replace the module after this happens.
7) Bad Steering Rack
The steering rack is one of the essential components of your car that receives high-pressure hydraulic fluid and helps drivers direct the wheel easily. If this becomes faulty, drivers will have trouble with handling, especially on rough terrain. Although uncommon, this is one place vehicle owners should consider checking if the Traction Control Light illuminates.
8) Faulty Steering Angle Sensor
The steering angle sensor is found inside the steering column and is essential for accurately measuring the steering wheel’s angle, position, and the rate at which it returns.
If its wiring becomes faulty, it will adversely affect the connection between the Traction Control System computer and the wheel, resulting in its failure to compute and process information correctly and triggering the Traction Control Light to illuminate.
9) PCM Issues
Your vehicle’s powertrain control module (PCM) plays a vital role in proper Traction Control function by taking over the said system.
So, if your Traction Control Light goes off and you find no external factor affecting the Traction Control System, then the computer system is having problems. The PCM can get errors or be reprogrammed to eliminate issues in its current programming.
Read More: Causes of a bad PCM
10) Limp Mode
The limp mode is a self-preservation security feature in cars that activates when it detects abnormal readings, a malfunctioning electrical component, or a mechanical operation.
For instance, your car starts acting up and behaving erratically. When these abnormalities happen, the warning lights on the car dashboard (including ABS and Traction Control lights) illuminate, car features are kept to a bare minimum with extras turned off or reduced, and transmission, speed, and RPM are limited.
Read More: Limp Mode Symptoms and Causes
How do you fix it if ABS Light Comes On?
You know there is a problem the moment the ABS light comes on. How to fix the ABS light depends on the nature of the ABS problem.
ABS diagnosis typically starts with accessing the associated DTCs and then applying the appropriate flowchart.
Performs the following repairs if your ABS light turns on:
- Turn the Ignition Key off and On
- Replace the ABS fuse
- Check the stator ring
- Replace ABS module
- Replace the ABS wheel speed sensor
- Replace the bad ABS Pump
1) Turn the Ignition Key off and On
If the ABS light is illuminating, the first thing to try is turning the ignition key off and back on. It’s like rebooting your computer. Maybe whatever transient issue that confused the ABS controller has passed, and all is well. If the condition repeats, you need to do some further poking and prodding.
2) Replace the ABS Fuse
If the ABS fuse is blown, replace it. Locate the ABS fuse panel under the dashboard and replace it.
3) Check the Stator Ring
The ABS wheel sensor works together with the stator ring to monitor wheel speed rotation. If the stator ring is damaged, it can cause a malfunction of the ABS.
Check to ensure the stator ring is not damaged or dislodged, resulting in missing teeth activating the ABS light.
4) Replace the ABS Module
The ABS control module monitors the wheel rotation speed and can sometimes go out. The computer module is on top of the pump motor and held by 4-5 mounting bolts.
If you hear a humming brake noise or the ABS light remains on after turning off the key, then it means one of the valve control coils is already burned out and needs immediate replacement.
5) Replace the ABS Sensor
Test the ABS wheel sensor or scan it for the presence of error codes such as C0035, C0040, C0041, C0045, C0046, C0050, etc. The error codes mean your car sensors are not plugged in or need replacement because of a short circuit. Replace the sensor using basic tools like a work light, screwdrivers, pliers, and other supplies in your toolbox.
6) Replace the ABS Pump
Replace the ABS pump module after ascertaining it’s leaking. The pump is on the driver’s side. Trace the black wire from the bleed abs module to the driver-side fender and unbolt it. Use a wire brush to clean the bolt and lug. Remove all the grime from the parts to leave them shiny and clean.
Apply Di-grease to the lug and bolt on both sides and in the bolt hole. Apply more Di-grease on the bolt and lug surface, including the wire housing. Ensure all metal surfaces are covered in grease.
Watch the video to understand better how to fix an illuminated ABS light:
How to reset ABS Light with a Scan Tool
A scan tool (OBD code reader) is the fastest way to identify and reset the ABS light. You do not need a specific abs scan tool. OBD scanners allow you to access the car’s central computer, where it can find fault codes stored in the system memory.
- First, find the OBD II port in your vehicle.
- Plug in the scan tool and turn the ignition to the second position (lights on the instrument cluster will be lit up, but the motor will be off.)
- Select clear fault codes.
- Turn off the ignition and unplug the scanner.
How to turn off ABS light Toyota?
- Open your hood and remove the negative battery cable with a socket wrench.
- Wait for at least three seconds.
- Reconnect the negative battery cable to your car battery.
- Tighten the cable with a socket wrench.
FAQ Section
What repairs can fix the Illuminated ABS Light?
- Inspecting and adding more brake fluid
- Replacing the blown fuse
- Replacing the bad speed sensor
- Replacing the bad hydraulic pump
- Replacing the bad ABS module
- Replace or reprogram the powertrain control module (PCM)
- Replacing the bad steering angle sensor
- Replacing the bad steering rack
- Fixing the limp Mode
How to reset your ABS Light?
- 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. Plug the cable back in to restore power. If there’s no remaining problem with the system, this should reset the light.
- If the light comes back on after the reset, you may need to change the ABS sensor. To do so, unscrew the housing for your sensor (you should find it mounted to the wheel hub) and unplug the wire. Then, attach and mount a new sensor. You may still need to reset the computer again via the method described above.
- If the light still comes on, you should use an ODB code reader to diagnose the problem, as the vehicle believes there is still a problem warranting the light. If you don’t have an ODB code reader, take the vehicle to a shop to solve the problem.
Is it safe to drive a car with an ABS light on?
Yes, it’s safe. The car brakes will still work under normal braking circumstances as usual, even with the ABS light on. However, the brakes will lock up under heavy braking situations, forcing the wheels to skid. Your ABS is very important during winter when your wheels lock up when you apply heavy braking on ice.
Driving with an ABS light on during winter is dangerous, as your vehicle can’t handle heavy braking in emergencies. The safety feature protects you from accidents and shortens your braking distance, giving you control over the steering.
Is ABS light on a serious problem?
When your car’s ABS light comes on, it means there is a problem with your vehicle’s braking system. You need to address this issue; otherwise, it could make your car unsafe to drive. ABS is a type of braking system used in all cars produced since September 1, 2011.
What to do if the ABS light comes on?
However, if both the ABS light and brake warning light are illuminated together, it signifies a much more serious problem, and you should not continue to drive. If this happens, you should bring your car to the nearest workshop and be careful with your brakes, gradually reducing your speed.
How much does it cost to fix ABS?
The ABS replacement cost varies according to the vehicle model, labor cost, and the type of part’s brand. The average replacement cost of the ABS control module is from $310 to $1,100. The wide price range isn’t really driven by labor costs, typically around $70 to $130.
Can low tire pressure cause the ABS light to come on?
The short answer is yes; low tire pressure can cause your ABS light to come on. The ABS (anti-lock-braking) system is responsible for maintaining contact with the road when braking. This suggests that you may have low tire pressure in one of your tires.
Why do ABS and Traction Control lights come on?
The ABS and Traction Control lights come on whenever the vehicle’s computer or PCM detects a malfunction, a faulty wheel sensor, or other mechanical failures. These warning lights do not imply anything severe by themselves but may point to a graver problem when paired with the main brake light going off.
Why is my ABS light on?
The four common reasons that typically cause the ABS light to turn on include a malfunctioning ABS module, low levels in the fluid reservoir, broken wheel speed sensors, or the system being turned off.