The ABS brakes (Anti-Block System o Antilock Braking System) is a mandatory safety equipment from July 2004 on all new cars sold in Europe. Its reliability is very high and many times it reaches the end of the car's life without having suffered any kind of damage. fault. However, there are circumstances where the ABS light on is not such a rare occurrence.
The importance of this security element is such that if ABS brakes fail, the car will indicate it with a specific warning light on the dashboard. Something that does not happen with other failures, which are usually grouped engine failure warning light.
Although the car will continue to brake with traditional hydraulics, the ABS system will be out of order and we will not have control over the direction of the car by locking the wheels if we brake hard. Also, when the car has electronic brake distributor, it is also out of service when the ABS fails. In these cases the rear wheels can lock even under normal braking, so it will be necessary to take extreme precautions and use the car as little as necessary before repairing the system.
Causes of ABS brake system malfunctions
Most modern cars are provided with check control and simply by plugging in the diagnostic machine in the workshop, the system will tell us which component is faulty. However, if we want to do a small review before going to the workshopThese are the items to check:
Faulty brake light switch
If the ABS light comes on whenever you brake very gently or when you keep your foot on the brake (for example at a traffic light), it is possible that the fault is from the switch located just above the brake pedal. It is a cheap replacement (15-30 euros) if what is wrong is only the switch, the most common symptom is that Brake lights don't come on or stay on forever.
Air in the brake circuit
Sometimes he work of ABS brakes can give error message if there is air in the circuit, since the bubbles alter the operation of this element. The ABS may interpret this as a fault and shut down.
This cause will be one of the main suspects if brake pedal sinks or you notice a spongy touch when squeezed. The repair goes through brake fluid bleeding, a task for which we recommend a professional unless you have the necessary mechanical knowledge.
Rigid pipes or flexible pipes of the brake circuit
If a tube or hose is bent, dented or crushed (for example by a stone) and the flow of brake fluid is restricted, the ABS may receive strange data and consider it a fault.
Seizure of brake caliper pistons
If rust or dirt takes its toll on the brake calipers, the pistons they may get colds or move with difficulty by squeezing the brake discs. The ABS can detect it as a malfunction in the system. If we have never changed the brake fluid and our car is many years old, it is an important point to check.
Piston seal leaks
As in the previous case, the escapes can be detected by the system as faults. For example, due to the drop in system pressure while keeping the brake pedal pressed. Take the car to the workshop as soon as possible, because with a breakdown like this should not circulate.
Sensor or wheel sensor cables
Although they are protected, the cables can be cut by a ricocheting stone, branches or other objects on the ground. Similarly, if the wheel sensor is covered in dirt or grease, the system will not work properly.
wheel gear ring
It is a strange breakdown, but it can happen that grease or rust cause the ring to fail.
If we get this far and we haven't found anything, we have no choice but to go to the workshop and prepare to drop a lot of money since probably the fault be one of these elements:
- ABS control unit. Sometimes it is not sold as a spare part and is a single piece together with the hydraulic group.
- Engine control unit. It could be that the fault is in the "body computer" of the car.
- Solenoid valves. Many times it is not repaired and the complete hydraulic group is sold
- pressure accumulators.
- Electric pressure motor.
How much does it cost to fix a car's ABS system?
Fix it in the workshop
As in most cases, the price will vary greatly depending on the make of your car. This is mainly because for some brands only complete kits are sold that include several parts, even when only one of them is damaged. Prices with workshop labor included are from 450 euros to 1.800 euros, and this difference does not necessarily correspond to whether the brand in question is premium or not.
If your car allows it, you can buy the separate items. In this case, prices do not usually fluctuate as much as in brand kits. For example, the ABS-ESP control unit usually ranges between 100 and 200 euros and ABS sensors They usually cost between 20 and 30 euros.
Of course, the price is also affected by the workshop where the repair is going to be done. Although being a mainly electronic element, A good tip is to take it to the official workshop or one specialized in your brand. This is especially important if your car is modern, as more and more vehicles are programmed to need to connect to the diagnostic machine or to the brand's systems over the network every time something important is changed. Otherwise, the control unit will continue to give an error and may even lead to other faults.
Fix faulty ABS yourself
In any case, if you have time and desire, you can check the status of any of the elements that we have mentioned before taking it to the workshop. At least those that are within your mechanical knowledge. You may save some money if you spend a few minutes and you discover that it was enough to purge the air from the brake circuit, clean the switch of the brake lights or replace a visibly damaged ABS sensor.
Have you had a fault with your car's ABS brakes? Reliability varies a lot from one brand to another. In the next video we show you the ranking of the most reliable car brands, according to the Organization of Consumers and Users OCU. This is the 2020 Reliability and Satisfaction Survey, in which 40.000 European drivers (8.000 Spanish) have participated, which brings out how the brands are doing in these sections today.
As you can see, it is a good guide prepared by the OCU, which allows us to know which brand we can trust the most. One ABS light on it is not very frequent, but it is something on which our security depends a lot, and if we can opt for a more reliable car, all the better.
In addition, even if we repair the car as soon as the ABS warning light comes out, (with which we would tackle safety problems), it is always appreciated that the vehicle we buy does not need extra investments. Or at least, that you need as few as possible throughout its useful life.
Images 3, 4 and 5: Brian Snelson, frankieleon, Truck Hardware
