Anti-lock Brake System (ABS) is a safety anti-skid braking system used to prevent the wheels from locking up during braking and maintain grip with the road surface.

So what does ABS mean?

Anti-lock Brake System, which is an active component, integrated into the braking system of a car and not only, because it is also found in heavy vehicles and even public transport, of course, being adapted to their characteristics.

ABS has a very important role in the braking system, but what you need to know is that it activates in unforeseen situations, thus becoming indispensable in emergency conditions.

The entire system, which prevents total locking of the wheels, consists of an ABS sensor, which is a small device placed on each wheel.

ABS sensor

The ABS sensor is very important when it comes to emergency braking, because it helps the driver, eliminating the risk of pedestrian injury and avoiding various collisions by the simple fact that it does not allow the wheels to lock.

In other words, it will keep the wheel moving until the car stops. It is good to know that it can also be activated depending on the driving styles of the drivers, especially when it comes to an aggressive one, which involves a sudden stop.

The ABS sensor is an integral part of the braking system, it works in accordance with the entire wheel gear. It should also be noted that outside the ABS system, each wheel is equipped with a sensor, so that in case of emergency braking, they will act independently.

As a driver, you already know that this is a rather complex assembly, which needs the optimal operation of the entire mechanism for the braking to occur in normal parameters.

The emergency braking assistance system, by default the ABS, helps you in the following situations:

• when the driver brakes suddenly to avoid an obstacle;
• in unfavorable weather conditions (rain or frost);
• in other unforeseen situations, which require emergency braking.

Thus, the ABS has the function of stopping the wheel lock by suddenly increasing the braking pressure, thus improving the whole process behind this complex action. Its benefits include reducing stopping distances, increasing safety and protecting all road users.

ABS - components of the braking system

Just because the ABS is a sensor, so a small part of the braking system, you must know that for its proper operation the entire assembly must be ensured.

The ABS braking system consists of:

• ABS sensors placed on each wheel, so 4 in number;
• an ABS modulator or pump;
• a computer or an ABS control module.

All of these will be engaged at the same time as the brake pump, calipers, discs and brake pads (some cars are equipped with clogs or drums, especially on the rear wheels). Therefore, the elements must work perfectly together for the braking system to work properly.

Often, the ABS system is seen as a complement to the braking system, but given that the sensors are placed directly on the wheels, it should be given due attention, especially when it comes to various faults.

What is the role of anti-lock devices (ABS)?

Many times, the owners of older cars, manufactured before 2011, consider that the ABS system is not very useful, the braking can be performed safely and in its absence. Although partially true, this statement should be supplemented by information that only stopping under normal driving conditions does not require these sensors, as they become useful only in emergencies.

Therefore, the role of ABS anti-lock devices becomes active during emergency braking.

ABS function

The ABS braking system is one of the best innovations in the automotive field, as evidenced by the fact that it has not been replaced since its inception. Indeed, it has been upgraded with other technical solutions, which will assist even better and which will work in interdependence with it. One of them is ESP (Electronic Stability Program) or ESC (Electronic Stability Control), which increases the stability and maneuverability of a vehicle when skidding.

Returning to ABS, its main function is to ensure the safe stopping of the vehicle in unfavorable conditions. Thus, it, with the help of a computer, will determine the pressure to be exerted when the brake pedal is applied, so that one or more wheels do not lock and slip (come out in the scenery or hit other participants traffic).

It should also be noted that the ABS sensor does not activate every time you apply the brake, so it will operate independently of the rest of the system.

Conditions in which ABS is activated on the car

Many people believe that ABS is usually activated in severe weather conditions, but this is only half true. So, to avoid confusion, if you are a novice driver, you should know that when it comes into operation, you will feel a jolt, in which case you do not need to be alarmed or think that the car has broken down.

The ABS will activate in one or more of the following situations:

• when braking is performed below the road grip limit and the wheels tend to lock;
• when combined braking occurs, especially in areas with different grip;
• in situations where the brake pedal is depressed suddenly;
• when the tires are worn.

Therefore, the ABS sensor will not only come into action in bad weather, but every time the pressure on the brake pedal is high enough to cause one or more wheels to lock. However, this also depends on the traction of the car, which can be on the front or on the back, but also on the grip class on wet surfaces of the tires, as well as other specific factors.

In case of emergency braking, the ABS system will detect the tendency to lock the wheels and will control with the control module the maintenance or decrease of the pressure, so as to avoid their complete locking.

Given the important role that ABS plays in ensuring the protection of passengers and other road users, drivers must ensure its operation in optimal parameters, especially since, due to many factors, it can suffer various failures.

ABS sensor faults

Once you understand the importance of anti-lock devices, you should also know that they can break down, so when most drivers wonder why the ABS is on board, there is most likely a problem.

There are several reasons for the problems that cause the ABS to ignite on board, among the most common being the harsh weather conditions, such as high humidity, but these are not the only ones.

ABS sensor malfunctions can occur due to various causes, but the most important issue is to fix it as soon as possible, as this can lead to damage to the entire braking system.

Why does the ABS warning light come on?

Therefore, the ABS warning light comes on board in various situations. The first is when there is a failure in the braking system.

You should know, however, that some cars have the TPMS sensor integrated in the ABS electronic control module, so its failure, although it will be indicated by the lighting of a specific warning light, can cause errors that lead to a signal to the anti-lock device. wheels.

Therefore, the pressure in the tires or, better said, its decrease can influence the appearance of an error message of the ABS sensor.

Due to the complexity of the ABS system, any small failure of one of its components can cause the entire assembly to fail.

Most often the sensors mounted on the wheel and the ABS pump fail, followed by its computer. Thus, a complex diagnosis is necessary for the correct detection and investigation of the problem and for a complete remedy.

Defective ABS sensor - symptoms

The first symptom that the ABS has broken is the ignition of its warning light on board. Then, there is the possibility that the fault can be found even while driving, when the brake pedal is suddenly depressed.

Regardless of the situation, when such things are observed, the driver must be very careful of obstacles and reduce driving speed, so that braking occurs under normal conditions, which does not cause the locking of one or more wheels.

It should also be borne in mind that when the ABS fails, it is not a mandatory condition for the entire system to be damaged, in some cases being a single sensor. This is another reason why the problem needs to be seriously investigated in order to avoid additional costs.

The main symptoms of ABS sensor failure are:

• total or partial lack of a braking response (this depends on how the whole system is connected to the ABS electronic control module);
• the need to forcefully depress the pedal when braking;
• complete locking of the brakes.

Therefore, when you notice any of these symptoms, which are also highlighted by the ignition of the ABS warning light on board, you may have a problem with the wheel lock system, which needs to be changed.

Replacing the ABS sensor

To change the ABS, you must first know where it is located. On most newer cars, manufactured before 2011, the control module is located inside the engine, but this is up to each manufacturer, so for safety, consult the technical manual of the car. This is not the case with sensors placed on wheels, but to know what needs to be changed, you will need a diagnosis of the entire system.

Another component of the system is the ABS pump, which can fail. It is located, together with the module, in the engine compartment, therefore any intervention that requires its disassembly should be performed in specialized services.

Returning to the faults of the ABS system, once the problem is detected, it can be changed. Usually the entire control module is replaced so that all faults can be remedied.

In terms of the costs associated with changing the ABS sensor, they will be comparatively higher than those of replacing other components of the brake system, so you need to be careful when you detect a problem.

Immediate detection and troubleshooting of the ABS system must always be a priority for car owners.

ABS is one of the most important components of the braking system, its main role being to stop the total locking of the wheels in forced stop conditions. The electronic control module is quite complex, given its function of ensuring the safety of passengers and road users.

So, to cut a long story short, ABS will not only intervene in bad weather, it can come into action even when there is no imminent danger, because the control module will calculate the pressure on the brake pedal and grip on the road. On newer cars, the ABS is complemented by auxiliary systems, which help even more to stop safely, in unforeseen situations and not only, so you have to pay the same attention to it as in the case of the brakes themselves.