What is ABS?

The ABCs of ABS…

Chances are that, as a driver, you’ve heard the term ABS. But what is ABS exactly? What does it do? And why does it matter?

ABS stands for “anti-lock braking system”, and it’s one of the most important safety features found in modern-day cars. 

Let’s take a look at ABS in more detail.

What is ABS? And what are the benefits of ABS?

As we mentioned above, ABS stands for “anti-lock braking system”. 

In the simplest terms, ABS prevents the locking of your car’s wheels and the resulting loss of steering control during an emergency braking situation. If you need to stop quickly and harshly, you can maintain better control of your vehicle and avoid a directionless (and dangerous) skid.

In short, ABS:

  • can stop your brakes from locking
  • should reduce the possibility of your car skidding
  • sees fewer accidents due to loss of control.

As a technology, ABS has been around since the 1950s, when it was initially developed for use by aircraft. Gradually, ABS found its way into cars around two decades later, and by 2004, it became a standard feature on all new vehicles sold in the UK.

Previously, any car without ABS was at risk of having the wheels lock due to any hard and steady pressure applied to the brake pedal. This often occurs in emergency situations when the driver attempts to stop suddenly and slams on the brakes.

This sudden braking could cause the car’s wheels to seize and lose traction on the road. The continued forward momentum of the vehicle overrides the tyre grip, and the car begins to skid regardless of what direction the wheels are facing and what direction the driver attempts to steer it in. 

ABS, on the other hand, prevents this paralysing of the wheels and allows you to maintain better control of the car, directing it away from or around danger.

So what does ABS mean in short? A safer, more controlled drive for all road users.

How does ABS work?

ABS works thanks to electronic sensors on your car’s wheels, which detect when they are in danger of locking up. 

They do this by monitoring rotation speed and whether the wheels are speeding up or slowing down. If significant pressure on the brakes is detected, as in the case of sudden braking, the ABS control centre activates a relief valve, intermittently increasing and decreasing brake pressure. 

This rapid pulsing of the brakes keeps your tires from locking and skidding so you can continue to steer the car. You may feel the pedal vibrating under your foot as it does this. Continue to maintain pressure on the brake until the vehicle safely comes to a stop.

Why is my ABS light on?

Depending on the make and model of your vehicle, your ABS light might look like this:

Source: Wikipedia

If your ABS light is on, it means there’s a problem with the correct functioning of the anti-lock braking system. Let’s take a look at some of the common culprits.

  • An illuminated ABS light could result from low brake fluid levels in the fluid reservoir. This is the first thing to check. Learn how to do that here.

Brake fluid is essential to the functioning of your car’s brakes. It takes the force from the depressed brake pedal, and because liquid doesn’t compress, the brake fluid translates this force into pressure. This pressure then causes the front and rear brakes to stop your vehicle.

  • Another common cause of an illuminated ABS light is a faulty ABS control module. 

This microprocessor is responsible for running diagnostic checks of the ABS. It also interprets the information from the wheel sensors and hydraulic brake system to release the braking pressure on a wheel that is about to lock and begin skidding.

  • The wheel speed sensors themselves could also be at fault. 
  • Finally, several other possibilities could see your ABS icon light up, including worn brake pads and blocked release valves. All deserve further attention.

If your ABS light is on, take your car to a garage or dealership for inspection.

Is it ok to drive with the ABS light on?

Legally, an illuminated ABS light is an automatic fail on your MOT. 

In Britain, an annual MOT (Ministry of Transport) test is conducted on every vehicle to assess its safety, roadworthiness, and exhaust emissions. An illuminated ABS light could indicate a safety issue with your car, making it a danger for you and other road users.

This is why even if you are not due an MOT, you should have your car checked if your ABS light comes on.

Not only does it mean the anti-lock braking system is deactivated, but if your car has stability control and traction control (as all cars manufactured in the UK after 2011 do), they will be disabled as well. This is because these control systems also rely on the same wheel speed sensors as the anti-lock system.

While a faulty anti-lock braking system may not affect regular braking, it could severely impact your ability to stop safely in case of an emergency. Should your warning light come on, it’s important to drive to your destination cautiously and have your system checked out by a mechanic to ensure your vehicle is safe.

An ABS problem will not go away on its own, and it’s crucial to note that if you have an accident and attempt to claim on your insurance, a faulty ABS may harm your claim.

How do I know if my ABS has failed?

While an illuminated ABS light signals a problem, it’s important to note that older cars with ABS may not have a dedicated ABS light. Instead, in the case of a fault, older cars may use a “check engine” warning light to signal a problem.

If your car is skidding, losing traction on the road or aquaplaning (skidding because of a thin film of water under the tyres, causing the tyres to lose their grip), it could be that your ABS is not functioning correctly.

In addition, if your brakes are not as responsive as they usually are or require more force to activate, it’s time to have the brake system checked out.

Your car’s braking set-up is a vital part of its safety system. Anything out of the ordinary should be looked at by a professional.

Is ABS always effective?

ABS works best on wet and dry surfaces with a solid grip, like standard tarmac. Proper tyre pressure and a healthy tread are essential for the anti-lock braking system to work correctly.

ABS is less effective on surfaces like ice, mud or loose dirt, snow, and gravel. In fact, many off-road vehicles have a function that deactivates the anti-lock braking system to better navigate those loose and slippery surfaces. A locked wheel may have a higher chance of stopping on loose surfaces because it can burrow into the gravel or snow, for example, helping to bring the car to a halt.

Can ABS reduce stopping distance?

No. It’s a common misconception that ABS automatically reduces the stopping distance. Its main function is to help you maintain control of your vehicle rather than bring it to a halt faster.

Of course, as we mentioned above, it often depends on the surface and conditions. The best practice is to stick with the speed limit and keep within a reasonable distance of the car in front of you.

How do I know if my car has ABS?

All cars sold in the UK after 2004 have ABS installed as standard. In fact, most cars manufactured worldwide today automatically have an anti-lock brake system installed. 

If you’re unsure whether your car has ABS, the easiest way to find out is to start your engine and check for the ABS icon on your dashboard. It should flash on briefly and disappear as part of your car’s system check.

You can also check your owner’s manual or, if you’re feeling adventurous, look for the presence of the ABS pump under the vehicle’s bonnet. Alternatively, you can simply ask your mechanic.

What if my car doesn’t have ABS?

For those older cars without an anti-lock brake system, drivers can make use of something called “cadence braking.” This technique can be helpful in trying to avoid the wheels locking. 

Cadence braking requires the driver to rhythmically pump the brakes should the car begin to skid. This intermittent increase and decrease of brake pressure should allow the driver to maintain steering control. 

In summary

ABS is an essential tool in your wheelhouse for safer driving. Being able to steer in the event of a braking emergency could mean the difference between ploughing into the car in front of you and being able to avoid it. 

Also read:
5 Reasons Your Car Fails Its MOT
Do I Need High-Performance Car Insurance? 
The Impact of Speed