What is ABS Anti-lock Braking System ) probably even children know. This system allows you to perform the most effective braking for the fastest possible stop of the vehicle. The system is electronic and is equipped with many sensors and a control unit that ensures that the wheels do not block during braking, that is, they “do not skid.” Such an invention saves hundreds or maybe even thousands of lives on the road every day. The ABS system prevents skidding and loss of control, which is very important on slippery roads, as well as in case of emergency braking.
In this article, I will tell you about how to check abs sensor in case of its malfunction, as well as in the event of an emergency indicator in the form of three English letters "ABS" appearing on the dashboard. You will learn how to check the ABS sensor at home in various ways using a multimeter.
The most common breakdown in the ABS system is an open circuit, when communication between the control unit and the sensor is lost. This can happen for various reasons, which you will learn about a little later.
How to recognize a malfunction of the ABS system or ABS sensor?
- As I said, the corresponding indicator lights up on the panel, this can happen while driving, braking, or when turning the key in the ignition. In the latter case, the appearance of the inscription indicates the self-diagnosis of the system, after you start the engine, the light should go out.
- When ABS system malfunctions during braking, you will not hear the characteristic sound of the ABS unit located under the hood and will not feel the vibration that occurs when you sharply press the brake pedal and try to spin the wheels.
What to do first?
It is necessary to check the ABS sensors located near each wheel hub. Your task is to detect a violation in the connection of the sensors, a wire break or damage to the ABS sensor housing. In any of these cases, you will somehow see the corresponding indicator on the panel, well, provided that the system control unit itself is stable and not "buggy".
Checking the ABS sensor - measure the resistance
- Let's jack the wheel on which, in your opinion, the non-working or faulty sensor is located, or each wheel in turn if you do not know for sure which of the sensors is faulty.
- Next, remove the wheel and get access to the sensor.
- Dismantle the housing, as well as the protective control unit and connectors that supply power to the sensors.
- After that, we introduce wires into the wire circuit with PIN connectors and commute them with a sensor and a multimeter.
- We measure the resistance and compare it with the one that should be by default (you can find it in the manual) or with a representative of your car manufacturer.
- We “ring” the wiring for an open or short circuit.
- Rotate the wheel while watching the readings of the multimeter, the resistance should change.
- Device - leg - 5-26 Ohm.
- The device - "mass" - from 20 kOhm and more.
Checking the ABS sensor with a tester - measure the voltage
- Jack up the wheel.
- Turn on the multimeter, set the measurement mode to DC voltage.
- We connect the electrodes of the device to the connectors and check the readings, while rotating the wheel (about 1 rpm).
- A working ABS sensor will show a voltage on the device ~ 0.25-1.2 Volts. If the wheel speed is higher, then the readings will increase accordingly.
How to check the sensor with an oscilloscope?
To diagnose the health or malfunction of the ABS sensor, you can even use an oscilloscope or, more simply, a tester. When connected, a graph will be displayed on the device, using amplitude analysis, one can judge the health or malfunction of the sensor.
The problem is that not every service station has this device, not to mention the garage in which you are going to conduct all your "experiments". The device is expensive, and quite difficult to understand, therefore, to work with it, you must have certain knowledge and skills.
In modern cars ABS system has a self-diagnosis function, using special software, you can read the error code and then decrypt it according to a special table.
Can an ABS sensor be repaired?
It is difficult to answer the question whether it is possible to repair this sensor, it is difficult to answer, it increasingly depends on the degree of damage and malfunction. If everything is a banal damage to the wiring, then solving the problem is not difficult. If the damage is more global, the core or winding is damaged, then most likely the repair of such a sensor will simply not be possible and will require a complete replacement. Despite the fact that 99% of experts recommend replacing the sensor in case of malfunction or problems with the winding, there are those who successfully restore these sensors at home using improvised means. You can learn more about this repair in the video below.
This video demonstrates how to repair the ABS sensor at home
That's all for me. Thank you for your attention, I hope you were interested, and you were able to learn something new for yourself. I look forward to your comments on this topic, perhaps you have encountered such a problem or managed to solve it. Until we meet again...
