What is ABS, and why is it so significant?
The Anti-lock Braking System (ABS) is one of the important car safety features. ABS prevents the wheels from locking when braking hard or on wet pavement. Locking up wheels results in skidding, increased stopping distances, and loss of steering capability.
ABS utilises sensors placed on all four wheels to monitor speed. When a wheel begins to lock, the system quickly modulates the brakes to maintain the wheel's traction with the road. That is why you may experience a pulsating brake pedal in emergency stops; it is the ABS system at work.
What is the ABS warning light indicating?
The ABS warning light on your dashboard typically displays the letters "ABS" inside a circle, sometimes accompanied by parentheses.
When you begin to turn the car on, the light should light up for a couple of seconds and then turn off. That's normal because the system performs a self-test.
If the light remains on, turns on when driving, or flashes, it means that the ABS system has registered a fault. The light indicates that the ABS system will not function normally.
Common causes of the ABS warning light
There are several reasons why the ABS light can turn on. Understanding the cause can help you address the issue efficiently.
Faulty wheel speed sensors
Each wheel has a speed sensor that monitors rotation. If a sensor fails or gets dirty, the ABS system may not detect wheel speed accurately, triggering the warning light.
Signs:
• ABS light stays on while driving
• The car may feel normal during braking, but the ABS won’t function in emergencies
Fix:
• Inspect each wheel sensor for damage or dirt
• Clean or replace faulty sensors
Faulty or broken wiring
The ABS sensors are linked to the car's ECU (Electronic Control Unit) through wires. When these wires are cut, damaged, or corroded, the system detects a fault, which causes the ABS light to illuminate.
Solution:
• Check wiring around each wheel and beneath the vehicle
• Repair or replace faulty wires
• Apply proper insulation and connectors to avoid future problems
Low or dirty brake fluid
ABS depends on brake fluid to work properly. Low or dirty fluid may prevent the system from functioning properly, triggering the ABS light.
Symptoms:
• Spongy or soft brake pedal
• Brake warning light can also come on
Repair:
• Top up and check brake fluid if necessary
• Drain old or dirty fluid and bleed the system
Blown ABS fuse
Similar to any electrical device, ABS has a fuse for protection. If the fuse explodes, the ABS system will be disabled, and the light will be on.
Repair:
• Take the ABS fuse from your vehicle's fuse box
• Insert the new fuse with the same rating
Defective ABS pump or module
The ABS module and pump regulate hydraulic pressure to the brakes. A malfunction in this system can cause the warning light to illuminate.
Symptoms:
• ABS light remains on all the time
• Brakes can feel odd during severe braking
Repair:
• Get a professional mechanic to inspect the module
• Repair or replace the ABS pump or ECU as needed
Wheel bearing problems
A faulty wheel bearing will interfere with the ABS sensor reading, making the system recognise a fault.
Repair:
• Check wheel bearings for wear or noise
• Replace defective bearings
Tyre size or pressure variance
ABS senses slippage by using wheel speed. Significant variations in tyre size or uneven tyre pressure can confuse the system and cause it to illuminate.
Fix:
• All tyres should be of the same size and type
• Check and maintain the correct tyre pressure
How to diagnose the issue yourself
Although some ABS problems are best left to professionals, there are a few simple checks you can do:
1. Inspect the brake fluid level in the master cylinder.
2. Check tyres for uneven tread wear or improper pressure.
3. Check for obvious damage to wheel sensors or wiring.
4. Check fuses that pertain to the ABS system.
If you are unable to pinpoint the issue, it is advisable to have your car serviced.
Risks of driving with the ABS warning light on
Driving with the ABS light on is dangerous since the system might fail when you need it most:
• Locking of wheels during emergency braking.
• Higher skidding risks on slippery or wet surfaces.
• Less control of sudden turns.
Even when the brakes feel fine under everyday driving conditions, a malfunctioning ABS system can pose a significant safety hazard, particularly in emergency braking situations. Hence, an immediate check-up is advised. Our technicians at ACKO Drive service centres run diagnostic scans to identify the problem. Whether it’s a sensor or wiring fault, we fix it using approved methods. Your ABS will perform as intended, keeping you safe on the road.
You can book a service appointment at ACKO Drive service centres online through the ACKO app or the ACKO Drive website. We offer free pick-up and drop-off services, saving you valuable time. Additionally, we will provide you with a detailed diagnostic report. Post your approval, we will begin the service or repair work. From car pick-up to invoice, everything is transparent, and you can track each step online.
How to fix an ABS warning light
The exact fix depends on the root cause:
1. Clean or replace faulty wheel speed sensors.
2. Repair damaged wiring connecting sensors to the ABS module.
3. Top up or replace brake fluid and bleed the brakes.
4. Replace blown ABS fuses.
5. Repair or replace the ABS pump or module if malfunctioning.
6. Replace faulty wheel bearings if needed.
7. Ensure tyres are the correct size and properly inflated.
Professional diagnostic tools are often required to reset the ABS system after repairs.
How to avoid ABS issues
You can minimise the chances of the ABS warning light coming on by following the steps below:
• Keep brake fluid levels in check and change stale fluid.
• Check tyres frequently and keep them at the correct pressure.
• Do not drive aggressively over potholes, road debris, or uneven roads.
• Have brakes, wheel sensors, and suspension serviced at regular maintenance.
• Install genuine or quality replacement parts.
• Get the ABS system inspected during periodic car servicing.
Final words
The ABS warning light serves as a crucial safety notification. It does not necessarily indicate that the brakes have failed completely, but it suggests that the anti-lock braking system will not perform effectively when you need it most.
Overlooking the light can be hazardous to your safety on wet, slippery, or rough road surfaces. Maintenance of the brakes, wheel sensors, tyres, and suspension at regular intervals is required to render the ABS system reliable.
Frequently asked questions
