When the ABS light came on, it presented a moment of discovery. It means there is a problem with the anti-lock braking system.
Sometimes, the problem is easy to fix and can be difficult. When driving, the vehicle constantly monitors the sensors to ensure everything works as intended.
Among the systems, the car monitors are ABS or the Anti-lock braking system. Why is my abs light on?
The ABS system monitors the wheels to ensure they are turning properly and at the same speed; if not the lights come on. They help the tires maintain contact with the road surface during heavy braking.
The lights remain on until you fix the core issues. Essentially, the lights alert drivers that their safety system is compromised or is no longer active. ABS helps drivers maintain directional stability and control during extreme braking situations.
ABS is common in modern vehicles and decreases accident risks by 18 percent, according to research findings. The system controls the rotational speed of every wheel to make the vehicle move in the desired direction, even if it’s sideways.
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.
Why is the ABS Light Important?
The ABS system is a critical safety feature, especially in slippery or emergency braking situations. Here’s why it matters:
- Prevents Wheel Lock-Up: ABS prevents your wheels from locking, allowing you to steer while braking.
- Reduces Stopping Distance: On slippery surfaces, ABS can help you stop more quickly.
- Enhances Vehicle Control: It helps you maintain control during sudden stops, reducing the risk of skidding or losing control.
Common Reasons the ABS Lights Come On
Here are some of the most frequent reasons the ABS light comes on in your vehicle:
#1. Faulty Wheel Speed Sensors.
The ABS system relies on wheel speed sensors to monitor the speed of each wheel. These sensors send data to the ABS control module, which adjusts braking pressure to prevent wheel lockup.
If a sensor becomes dirty, damaged, or malfunctions, it can send incorrect data to the system, causing the ABS light to come on. This is one of the most common causes of ABS-related issues.
#2. Low Brake Fluid Levels.
Brake fluid is essential for the proper functioning of both the ABS and standard braking systems.
Low brake fluid can cause the ABS to malfunction, leading to the warning light being triggered. Checking and maintaining the correct brake fluid levels is crucial for the system’s effectiveness.
#3. Worn Brake Pads or Rotors.
Over time, brake pads and rotors can wear down. If they become too worn, the ABS system may detect reduced braking performance, which can cause the ABS light to illuminate as a warning that the brakes are not functioning as they should.
#4. Malfunctioning ABS Module.
The ABS module is the control center of the system. It processes data from the wheel speed sensors and adjusts the brake pressure to prevent wheel lockup.
If the ABS module malfunctions due to electrical issues, internal damage, or water ingress, the system will shut down and the ABS light will turn on.
#5. Damaged Wiring or Blown Fuse.
The ABS system depends on a complex network of wiring to communicate between the sensors and the module.
Damaged or corroded wiring can interrupt this communication, causing the ABS light to turn on. Similarly, a blown fuse within the ABS system can prevent the system from working, resulting in the warning light illuminating.
#6. Faulty Hydraulic Pump.
The hydraulic pump within the ABS system helps regulate brake pressure when the system is activated. A malfunction in this pump can prevent the ABS from functioning properly and may cause the light to come on.
#7. Problems with the Traction Control System.
In some vehicles, the ABS is linked with the traction control system (TCS). If there’s a fault in the traction control system, it can trigger the ABS light.
These systems share certain components, such as the wheel speed sensors, meaning a problem in one system can affect the other.
#8. Worn or Defective ABS Rings.
The ABS system uses rings to monitor the speed of the wheels. If the rings become damaged or worn out, they can cause the ABS light to turn on. Regular inspections and timely replacement of worn ABS rings can help avoid this issue.
How Do You Diagnose the ABS Problem?
ABS system works with the braking system to maintain control in case of heavy braking in an emergency like slippery or wet roads. Signs of trouble include rapid pulsating brake pedal or slight vibrations. To determine the issues, perform the following diagnostic steps.
Step 1
Insert the key in the car ignition and turn it on and off to see if the light comes on the dashboard. Sometimes, this solves the problem as it resets the code stored in the system memory. This is how to reset the ABS light without a scan tool.
In case the issue persists, take the vehicle to an auto shop for a scan to locate and fix the code.
Step 2
If the ABS pulses at low speed, clean the front wheel sensors while applying little pressure. clean the wheel sensors or take the vehicle to an auto shop for cleaning of the wheel sensors.
Step 3
If the vehicle won’t stop, apply more pressure to the ABS brake. Check the master cylinder brake fluid level and refill it to the marked level if it’s low. Also, it means that air may be in the hydraulic system, resolving the situation by bleeding the hydraulic system.
Replace any broken or loose front-end parts if there is a clunking noise as you press the ABS brakes.
Passive wheel-speed sensor diagnosis
A common ABS failure and classified as dynamic and static. Static failure includes wiring problems and sensor coil failures. Dynamic failures are related to signal quality problems.
Do a visual inspection for the sensor mount, speed sensors, pigtail, and sensor tip in case it’s exposed, and check the connector. For exposed tone rings, do a tooth-by-tooth inspection for damaged or cracked teeth tone rings.
Check the sensor to harness the connector for problems like corrosion, pin problems, or water intrusion. Inspect the ECU connector and pay close attention to pins that may be pushed out.
Check for a loose wheel bearing as it allows fluctuation of the air gap, leading to a false activation or DTC.
Performs ECU diagnosis
Perform generic tests to verify that power and ground are getting to the ECU. The proper operation of ABS depends on the proper grounding of ECU and the ECU receiving the right operating power.
Locate the ground and power circuits, then perform voltage tests for the power and continuity tests for the ground.
Every new car in the United States has an ABS requirement since 2013. Automakers are including the standard equipment into other vehicle models made in the late 1980s.
ABS sensors tell your dashboard controller when your wheels stop rotating when the vehicle is in motion. It’s a sign that the brakes have locked up.
The controller then directs a hydraulic valve to release the brake fluid pressure to the wheels to facilitate wheel rotation again. The process repeats every time until the vehicle stops or your foot is off the brake pedal.
How Do You Fix 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.
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.
Is It Safe to Drive with the ABS Light On?
While your regular brakes may still work when the ABS light is on, it’s not advisable to ignore the issue. Here’s why:
- Reduced Safety: Without ABS, your wheels may lock up during sudden braking, especially on wet or icy roads.
- Potential for Further Damage: Ignoring the problem could lead to more expensive repairs down the line.
- Failed Inspection: In many regions, a lit ABS light will cause your vehicle to fail its safety inspection.
If the ABS light comes on, it’s best to have your vehicle inspected by a professional as soon as possible.
Preventing ABS Light Issues
Here are a few tips to help prevent the ABS light from turning on in the future:
- Regular Brake Maintenance: Regularly inspecting and maintaining your brake system, including brake pads, rotors, and brake fluid levels, can help prevent ABS-related issues. Early detection of worn components can stop the ABS light from coming on.
- Clean Wheel Speed Sensors: Dirt and debris can interfere with the operation of the wheel speed sensors. Regularly cleaning these sensors will help ensure they provide accurate data to the ABS system, preventing false warnings.
- Monitor Brake Fluid Levels: Checking your brake fluid levels regularly and topping them off when necessary can prevent many common ABS issues. Keeping the fluid at the recommended level will help the system function properly.
- Address Early Warning Signs: If you notice any signs of reduced braking performance, such as squeaking brakes or longer stopping distances, have your brakes inspected immediately. Addressing minor issues early can prevent more serious problems with the ABS system.
How Much Does It Cost to Fix ABS?
Fixing ABS may cost $300 – $1000 depending on the problems and mechanic.
To fix the ABS module, it’s usually between $300 to $1000. An extra cost may be incurred to get a professional to fix the problem, costing $100 above.
A faulty ABS may be caused by different reasons, such as a faulty ABS sensor or a damaged ABS module.
If your faulty ABS results from a defective or damaged ABS sensor, it may not be as expensive as fixing a damaged ABS module. It costs between $200 and $400 to replace an ABS sensor.
If you are replacing your ABS module, you will be spending between $300 and $1000. The price may cost more depending on the brand and model of vehicle your use and how hard it is to find the module control.
Some ABS problems are traced to fewer problems, like low brake fluid will cost even less. All you need to do is refill the brake fluid, which will cost between $5 to $30.
FAQs.
Q: 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 system is very important during winter when your wheels lock up when you apply heavy braking on ice.
Driving with ABS light on during winter is dangerous, as your vehicle can’t handle heavy braking in emergency situations. The safety feature protects you from accidents and shortens your braking distance, giving you control over the steering.
Q: How much does it cost to fix the ABS system?
It will cost approximately $200 if you factor in the cost for ABS diagnosis and labor costs. However, the estimate doesn’t include taxes and fees and varies depending on your location.
However, if you have to replace the ABS system, you can pay an additional fee of $200-950, depending on the ABS module part. Many garages will fix your ABS for between $340-1100 in total.
Q: Can Low brake fluid cause the ABS light to come on?
Yes, an ABS light comes on when there is a low brake fluid level in the ABS fluid reservoir. The warning light means you have an abnormally low fluid level.
Turn off the engine and restart by turning it on again to see if the warning clears. If not, check if the light is intermittent. If so, it means the brake fluid level is slightly low.
Q: Can worn brake pads cause ABS light to come on?
No. Worn-out brake pads don’t cause the ABS light to come on. The light is triggered by a low brake fluid level, an abnormal wheel sensor, and a blown fuse.
However, it’s good to replace worn-out brake pads to improve your braking as a safety precaution. Replace worn brake lines to improve your car braking efficiency.
Q: What can cause ABS to fail?
ABS rarely malfunctions unless the ABD controller is malfunctioning because of one or more sensors or faulty sensor wiring.
The most common cause is the contamination of sensors by corrosion, debris, or metal shavings. You will only notice a failure the moment you slam the brakes and notice the wheels are locking up as you drive.
Final Thoughts
Always be observant when driving and listen to abnormal brake noises that indicate a problem.
Observe the ABS module or your dashboard for a warning light that shows performance issues. American-built cars don’t need code clearing. Some Japanese and European-built vehicles may require code clearing using an ABS code reader.
If the ABS warning light still remains after code clearing, it means there is still a problem that needs fixing.
To fix the issues, you need various supplies and tools like repair manuals, toolboxes, safety, cleaning supplies, floor ramps, jacks, and stands. You also need parts replacement like the controller/computer module, wheel speed sensor, and ABS system fuses.