DIY abs repair

In detail: do it yourself abs repair from a real master for the site my.housecope.com.

In the instructions, we will repair the unit of the brand - Bosch. This is not the best of abesoks, and in addition, this is exactly what is installed on most brands.

for instance in Audi, Volkswagen, Ford, Skoda, Seat, Renault and even Mercedes come across.

Location of the ABS unit under the hood of the Audi A4

The problem starts with a pesky error and a full screen exclamation mark. Because of which nothing else can be shown by the tidy, it cannot until it fixes the problem.

Everything would be fine and it seems possible to drive, but when selling, the buyer often asks a lot of questions seeing this disgrace. And the most calm when on the electrics - everything is in order.

More often, a breakdown occurs in the electronic part of the unit.

The contacts there are thin and fragile. If the problem is similar to the one described below, with sufficient experience with a soldering iron, you will succeed.

We disassemble.
First, let's remove the electronic part. It is connected to the hydraulic (main) part by six bolts. Disconnect the supply cable, then crawl up and unscrew it with a convenient key.

12 contacts of the electro-module

Now you need to carefully open the plastic case of the module. We cut with a cutter along the seam, very carefully, without driving the knife deeply. You can touch the contacts inside.

The case has been opened.
We carefully examine the board under a magnifying glass and a bright lamp. Inspection of this unit revealed damage to two contacts on the left side going to the connector.

From the outside, everything seems normal.

By slightly moving these wires, they easily moved away from the contacts.

Gently solder the wiring into place. You can also solder a new common wire instead of these two. You need to solder very carefully - do not overheat the entire module with the board.

Video (click to play).

If in the soldering experience they are not strong - it is better to give it to an experienced friend or to the workshop.

We glue the case back - with good glue (not super).

We return the module to its place.

This instruction was used by: 10995 once.

Most modern cars are equipped with a set of systems aimed at driving safety. To prevent wheel blocking during heavy braking or on a slippery road, the anti-lock braking system ABS (ABS) is used. Fully locked wheels are known to increase the stopping distance of a car, and if only a few wheels are locked, the car is more likely to skid.

The ABS includes several systems - the anti-lock braking system itself, the stability control system and emergency braking. The whole complex is controlled by an electronic control unit, and the final device is the hydraulic system of the vehicle.

Signals for the operation of the ABS systems come from a sensor installed on each of the wheels and monitoring the rotation of the wheel at each moment of movement. Based on the speed of the vehicle, the speed of rotation of the wheel, the condition of the road surface or the angle of inclination of the road, signals for the control valves of hydraulic systems are generated at the output of the electronic unit.

The ABS system is very important for the safe driving of a car, therefore, before undertaking repairs with your own hands, you need to carefully weigh everything. Diagnostics and repair of blocks of the ABS system in a car service, even if it will cost a little more than with your own hands, will give a guarantee that failures will not occur at the most inopportune time.

This is especially true for those who are accustomed to using the ABS and rely on its performance.

Like most electronic systems, the ABS has primary self-diagnostics that operate when the key is turned. Diagnostics usually takes a few seconds.If after this time no system malfunctions are noticed, the alarm on the dashboard will go out. When the car is moving, the ABS diagnostics works continuously, and when the parameters of the sensors or terminal devices are not included in the tolerance zone, a malfunction alarm is triggered. When signaling a malfunction, it is necessary with special care to find a convenient place to inspect the car or get to the nearest car service, especially in cold weather, when the roads are slippery. Sometimes it happens that a malfunction can be eliminated with your own hands in a couple of tens of minutes.

To repair blocks of the ABS system with your own hands, you must first measure the voltage of the battery. If the voltage is less than 10.5 V, the ABS control unit will not turn on, so that there are no errors in operation. At normal voltage, you will have to continue troubleshooting. Most of them are due to the wiring of the sensors. Moisture, getting into the connectors, causes oxidation of the contacts, therefore, first of all, you need to assess the condition of the contacts of each sensor of the ABS systems.

Very often, breakdowns of ABS systems are caused by a malfunction of the control unit sensors. To operate the ABS sensor, a gear wheel is attached to the hubs, and the sensor itself is an inductor located at a distance of 0.2–1.5 mm from the teeth. If all the teeth are in place, then it is necessary to measure the gaps between them and the sensors, if necessary, readjust the mounting of the sensors. Dirt accumulated on the teeth and surfaces of the sensors can adversely affect the operation of the ABS.

The coils themselves are checked with an ohmmeter. The device should show a resistance of 1-3 kOhm, depending on the type of sensor. The main thing is that they are all the same on one car. If the ABS sensor coil shows an open or short circuit or is very different from the rest, then it needs to be replaced or repaired. One can only advise to check the place of entry of the connecting conductors into the device. Perhaps the wires are broken, and, having removed a little insulation from the sensor, you can try to solder the break or short. Many devices can be disassembled by heating them with an assembly hair dryer and removing the plastic cover at the wire entry point. It is under this cover that breaks occur most often. In this case, do-it-yourself ABS repairs will not be very serious. Considering the cost of the sensor, such a technique may have a right to exist.

If the sensors are in order, the state of the wiring from them to the electronic unit is not satisfactory, then you need to inspect the control unit. DIY repair of ABS control units is advisable only for those who are very well versed in electronics, know how to use a soldering iron and have the skills to repair electronic devices.

The ABS control unit, as a rule, is made non-separable and hermetically sealed with glue. The printed circuit board on it is filled with a special sealant. If you carefully open it, you can look at the wires soldered to the printed circuit board of the block. Very often they do not withstand vibration and come off. The broken wire must be carefully evaporated and another must be soldered instead. For soldering, you need to use an electric soldering iron with a power of no more than 40 watts. Rosin or its solution in ethyl alcohol is used as a flux.

Do not use soldering acid for soldering ferrous metals as it will corrode printed tracks and copper wires over time.

To check the coils of the hydraulic valves, you need to free their leads from the sealant and apply a voltage of 12 V. A normal coil should work like an electromagnet, attracting steel objects.

Coil rewinding and PCB repair should only be performed by a specialist. It is very difficult to do this with your own hands and, moreover, without any guarantee.In any case, after the repair has been completed, the sealant layer must be restored. You can use neutral silicone for this. Regular silicone contains acetic acid. It cannot be used categorically.

Some time after the repair, the printed conductors on the control unit board will be completely corroded. For the most part, replacement of the control unit is required.

One more note. When replacing brake fluid in a car, it must also be drained from the accumulator (pressure accumulator) of the ABS. This can be done by pressing the brake pedal several times with the ignition off. With the ignition on, the pump in the hydraulic block will try to make up for the loss of fluid. In order to avoid damage to the electronics, during welding on a car, the ABS control unit must also be disconnected from the power circuits by pulling out the connector.

Like any other system in a car, the ABS periodically requires maintenance, preventive maintenance and repair. Of course, all the electronic units of this useful system are well protected from external influences and rarely fail, but every motorist should be prepared for the fact that sooner or later they will have to roll up their sleeves and start preventive or repair work. Periodic self-diagnosis is not canceled even by the presence of a self-test system in each car.

It is necessary to pay attention to the prevention of ABS, since it performs a very important function in the car - it prevents the complete blocking of the wheels during braking. This, in turn, not only reduces the braking distance, but also allows the driver to maneuver during braking - without ABS, with locked wheels, any steering movement will lead to an uncontrollable skid of the vehicle, the consequences of which can turn into a disaster.

It is quite natural that do-it-yourself ABS repair is possible only if the problem is accurately identified. Any car with an anti-lock braking system also has a self-test mechanism that is activated when the ignition is turned on. If the system is faulty, an error code is displayed on the on-board computer. Having looked at the instruction manual, the driver will easily understand the current problem and appreciate the possibility of self-repair.

The entire anti-lock braking system can be conditionally divided into a central part, which includes electronic and hydraulic units, and a peripheral part, which includes wheel sensors. It is they who most often become the culprits of failures in the operation of the ABS. The second most popular cause of problems is worn wiring and poor connections that are unable to ensure the integrity of the electrical circuit.

The main part of the ABS is the electronics and the hydraulic unit. They fail quite rarely, and their self-repair is highly undesirable without the appropriate equipment and qualifications. If the reason for the interruptions in the wiring, terminals or the sensors themselves, which are installed on each hub, it is quite possible to do without a visit to the car service.

If it is almost impossible to repair the ABS unit with your own hands, then the wires and sensors are completely at the mercy of the driver. If the ABS indicator lights up frequently while driving, the first step is to check all the wires leading from the unit to the sensors. They should not have strong creases, damage to the insulation. If there are bare areas, such wiring must be urgently replaced - it is better to spend a little time on this than to find yourself in a critical situation without the help of the ABS.

The next step in self-troubleshooting of the ABS will be checking the sensors. To accurately determine their performance, you will need a multimeter with which the resistance on each of them is checked. The normal values of this indicator can be clarified in the car operating manual - for each system it can differ significantly.To check, you need to either lift the car with a lift, or alternately jack up each wheel.

Each sensor is a fairly simple induction coil, so there is no difficulty in understanding whether it is functional or not - if the resistance does not correspond to the standard, the sensor must be definitely replaced. The cost of a new one is not high, the sensor cannot be called a deficit either, and the procedure for self-replacement is not difficult even for a novice car owner.

Normally, after turning the ignition key, the ABS indicator on the dashboard should light up, and after 3 seconds go out - this indicates a successful self-test and no problems. If it continues to burn, or lights up while the car is moving, it is advisable to perform the following actions:

park and turn off the engine;
try to start the engine again after 3-5 minutes;
check the voltage at the output of the battery with a multimeter - its minimum value should be 10.5 V;
check the quality of the contact of the power wires, as well as the wires leading directly to the ABS sensors on the wheels.

To do the above, it will take no more than 5-7 minutes. If, after a cursory check of violations, it is not possible to identify the violations, you will have to seek help from professionals, or do it yourself, having devoted a lot of time to checking each sensor.

As practice shows, more than 80% of ABS malfunctions are associated precisely with sensors located on the wheels. They have to work in very unfavorable conditions, therefore, periodic problems that arise in their work are more likely a pattern. When starting to repair ABS with your own hands, you can go in two ways - just replace the sensors with new ones or restore the old one to work. In the latter case, you will have to rewind the coil located inside the sensor - this is a difficult and painstaking job, and without skills, a positive result is not guaranteed.

It is much easier and more reliable to replace the sensor. To do this, you need to remove the old one, which is attached to the hub with one bolt. To get to the attachment point, you will need to dismantle the wheel, remove the caliper and brake disc. To make it easier for yourself to remove the sensor, you can pre-treat the mounting area with WD-40. Install a new one in reverse order. Repairing the anti-lock braking system, in addition to replacing the sensor, should also include checking the wires; if damaged, they should also be replaced. Otherwise, even a new sensor will not be able to ensure the smooth functioning of the system, and the slightest short circuit will lead to its immediate shutdown. How to properly repair the sensor is shown in the video:

Read also: DIY TV repair

Modern anti-lock braking systems (ABS) have long ceased to be a sign of an elite car - they are installed on most new cars coming off the assembly line. While this useful piece of equipment is quite reliable, it still has a number of problem points that can affect smooth operation. The most vulnerable elements of the ABS are the wheel speed sensors located on the vehicle's hubs.The ABS sensor is an inductor paired with a toothed disc, which is also mounted on the hub. Together they measure the speed at which the wheel is spinning. The first symptom of a device malfunction will be the signal of the warning lamp located on the dashboard of the car.When the system is stable, the controller goes out a few seconds after the engine is started. If the indicator stays on or starts blinking chaotically when the car is moving, anti-lock brakes require immediate intervention.Along with the signal of the indicator lamp, a sensor malfunction is indicated by:

alphanumeric error code of the on-board computer;

lack of characteristic sound and vibration when pressing the brake pedal;

permanent blocking of wheels during emergency braking;

parking brake controller light signal when the equipment is off.

The appearance of any of these symptoms requires a complete system diagnosis. Note that the help of car service technicians in solving this issue is completely optional. There are various ways to test an ABS sensor, and in most cases it is easy to do the job yourself.As a result of device diagnostics, it is possible to determine in which sensor assembly there is damage. If the tester readings tend to zero, this indicates a short circuit in the connection wires, "infinity" signals a violation of the integrity of the coil winding. There is an opinion that the repair of the wiring does not cause any problems, but the faulty sensor is easier to simply replace. It is difficult to disagree with the first thought, but the next "point" can be disputed.The fact is that the cost of some sensors reaches 14-18 thousand rubles, and you will have to wait for their delivery for a long time. Having certain skills, a stock of patience and natural ingenuity, it will be much more useful and faster to repair the device than to pay for a long-awaited expensive order. Note that this advice is only advisory in nature - the final verdict is yours. If the decision to repair is still made, we will be happy to help you to carry it out correctly.After diagnostics and detection of a faulty element, the device must be dismantled for further repair. The process of removing it is similar to the first stage of measures to replace the ABS sensor and is not particularly difficult.Attention! Elements can stick to the seat; it takes a lot of patience to remove them from the slot. Professional technicians advise to moisten the metal around the device abundantly with WD-40 liquid and carefully remove the sensor, slowly loosening it.Having finished dismantling the device, we proceed to the repair work:The repair of the sensor is completed, you can mount it on the hub by grinding the new body with sandpaper for a better fit to the seat. When installing a repaired device, be sure to observe the following conditions:

Place the sensor core parallel to the teeth of the counter disk, making sure that it does not overlap two adjacent teeth.

We leave a gap between the tine and the core of 0.9–1.1 mm.

The final stage in the repair of any of the ABS elements is to check the system operability. We carry it out by starting the car engine and making sure that the controller on the dashboard goes out 3-5 seconds after the start.Attention! If the ABS indicator lamp periodically lights up when the car is moving after repairing the sensor, change the phasing of its connection wires.Note that some sensors produced by the foreign auto industry can be disassembled without a fundamental violation of the integrity of the structure - the upper shell of the part can be removed by pre-heating with a construction hairdryer or blowtorch. An example of repairing such a device is shown in the video.

When replacing the wire, we install sealing rubber bands at the points of its attachment to the body

Attention! When connecting the wiring to the ABS sensor, take into account that the device has polarity.In the vehicle operating instructions, the color coding of the wires is indicated - on the connector of the part there are exactly the same designations.

In more detail, the process of repairing the ABS sensor wiring is described in the video presented.

Repairing an ABS sensor is a very time-consuming and troublesome task. If you are not distinguished by perseverance and patience, or simply do not have free time, you probably should not get down to business. Well, those who are accustomed to solving all problems on their own and do not want to spend extra money will now easily do this work on their own.DIY abs block repairDo-it-yourself ABS malfunctions and repairs - you can fix something yourself, without a car service. Almost all modern cars are equipped with an anti-lock braking system. In this case, it is required to carry out the ABS diagnostics regularly.As soon as the ABS and the ESP stabilization system fail while driving, the vehicle's controllability is immediately lost. This can lead to an emergency. Accordingly, a broken unit should be repaired in time. Bezares hydraulic pumps include all the most demanded types according to the method of connection.This system has three components: there are wheel sensors, electronic and hydraulic control units. The service station is mainly contacted about a malfunction of the wheel speed sensor, electrical wiring, and the control unit.Only at the station can the malfunction be accurately determined. The ABS system is considered reliable, it is capable of functioning for a long period. Electronic blocks are protected from breakage, for this purpose, special relays, fuses are installed. Wheel sensors are mainly broken, they are located near the rotating components of the hub, axle shafts.Any contamination, significant backlash in the hub bearings can cause malfunctions in this system. It is not worth repairing the ABS yourself. You can only remove the wheel sensors, install them. The equipment is located in the steering knuckles, as well as on the axle shafts of the rear suspension. Do-it-yourself ABS malfunctions and repairs - The procedure for removing, installing sensors is carried out in this mode: - disconnect the sensor wire, connect a new one.

DIY ABS malfunctions and repairsIt must be remembered that the functionality of the ABS is influenced by the voltage parameters that are formed between the terminals of the battery. If the voltage drops below 10.5 V, the safety electronic unit shuts down the system.The safety relay will work at the moment of large fluctuations, sharp "surges" of voltage. To avoid such a situation, you need to follow simple rules: - when the engine is running, do not disconnect the electrical connectors; - do not start the "engine" from an external battery (it is advisable not to provide your car for this ); - we monitor the condition of the contacts on the generator; - before starting welding, it is necessary to disconnect the wiring from the electronic unit; - during painting the car, we do not heat the car over 85 degrees for more than 2 hours. valve body ABS, discharge. This is done by repeatedly pressing the brake pedal when the ignition is turned off.With the ignition off, the electric pump in the hydraulic unit will work. If the system is depressurized, liquid will leak out immediately.Sooner or later, everything comes to an end. There is nothing to be done, this is how the world works, I thought, looking at the deceased ABS of my Ford Mondeo.While looking for a replacement for a faulty part, I came across a wonderful instruction of one och. a good person who told in detail how to bring the Mekatronic 3 ABS back to life and, as you understand, decided to try it. See for yourself what happened next.

Self-test of the brains of the ABS at the moment of start. Clean combs on the CV joints and serviceable ABS sensors. When you press the brakes on the ice, the headlights and the dashboard go out. Working (not blown out) ABS fuses (fuses in the cabin: N30 7.5A brown, power supply of the signal lamp, through diode N22 7.5A brown, power supply of electronic control module ABS.) Under the hood fuses: N7 30A light green, power supply of the ABS pump, N3 60A yellow, power supply of the relay unit, ABS N10 20A light blue, power supply of circuits N22 and N30 through the lock ignition.

1. It is better to check the voltage at the connectors on the ABS unit. In the connectors on the side of the latch type, you need to pull out and remove the connector. Then use a multimeter to ring the wheel sensors, that is, feet: 7-8 (rear left), 9-10 (rear right), 21-22 (front left), 23-24 (front right). The connectors for the sensors are located as follows :

Front wheels - under the protection of the arch from above behind the spring can be found if you “walk” along the wire. Rear wheels - under the back row sofa, one on each side.

All these are signs of an inoperative ABS motor.

In Mekatronic 2 - (1993-1995) the case is one-piece, protected from dust and moisture, there are two connectors for wires. In Mekatronic 3 - (1996-2001) the case is collapsible with a drain hole, there is one connector for wiring.

The problem with these systems, unfortunately, is that there is a drainage hole in the plastic cover. It is located, as expected, in the lower part, however, the very location of the hydromodulator mount is not well thought out and is very dirty, as a result of which water and dirt get through the gap. Attention! This manual is only suitable for Mecatronic 3! If everything agrees with you (and the symptoms and description of the ABS), we can go directly to the repair.

Hexagons at “5” and “6”. Multimeter.

First of all, I turned off the power, that is, I removed the battery. Further, for convenience, I removed the air filter housing. After that, it is necessary to remove the vacuum brake booster, this is done with a key on “13” they need to unscrew 4 nuts. Disconnect the brake pedal, which is attached to the vacuum bushing. Part the antennae and remove the white latch, which resembles a tube, and then remove the vacuum amplifier itself. Try not to damage the anthers on the VU, as well as on the bulkhead between the engine compartment and the passenger compartment. Remove the ABS, that is, disconnect all tubes and wires from the ABS unit using two keys: “11” and “13”. Unscrew the two nuts on the bulkhead between the engine compartment and the passenger compartment, as well as two nuts near the left wheel. Disconnect the wiring block, for this it is enough to move the white lever towards the headlights, after which the connector is pulled out. Remove the wiring harness from the hook located near the wheel and from the hook on the bulkhead.

Remove the black metal cover, which is fastened with two hex bolts at "5". Then the second, hex bolts at "5" and "6" and we see the anchor. Next, you need to remove the ring and the bearing located at the end of the armature. Since it cracked in half, I had to buy a new ball bearing of the size I needed for the inner ring. After almost half an hour, I managed to get the bearing to fit. I had to cut the outer ring with a grinder in order to remove it internally. I figured it’s nothing, it’s okay with the support of the antennae, but still somehow not very confident. I greased everything with graphite grease for the CV joint and put it in place. Then I screwed the covers back and proceeded to reassembly. I put it in place, and I covered the drain hole with a piece of rubber.

As you can see, I got off, as they say, with little blood, instead of a complete replacement of the block, which would have cost me more than one thousand, I risked and saved, as a result, the repair of the ABS cost me several hundred rubles, which were spent on the bearing. Thank you for your attention, try it, and you will definitely succeed.Tue 27 Nov 2012 Heading: Auto electrics Basically, the design of all ABS units and their repair is in many ways similar to other units, so if your ABS unit breaks down, then in this article we will look at how to repair it with our own hands. Here are the symptoms: - if, when connected to the diagnostic connector, there is no connection between the computer and the ABS unit, or an error may pop up:

01203 - Electrical Connection between ABS and Instrument Cluster 03-10 - No Signal - Intermittent When the car is constantly on or the STOP (!) Or ABS lamps periodically light up and the buzzer rings 3 times.

All operations that will be described in this article are for informational purposes only. The ABS unit is a part of the brake system and according to the traffic rules, any intervention in it is prohibited.

Our recommendations ... I want to inform you that if you have never disassembled anything, then you had better not do it ... Several units were repaired by this method, and they all work fine and function. So the description itself ... Any ABS unit usually consists of 2 parts, the valve body itself and the electronic unit. The ABS unit is a very clever thing, which even if it fails, then you will in no case lose the brakes, no, they will work in a simple mode, bypassing this unit.Even when you remove it from the car and then you can safely sit down and drive and the brakes will work ... So the repair itself ... We remove the electronic unit from the car, what is needed for this: Jack up the wheel on the left side, remove it and substitute some piece of wood or bricks for your safety, (you will have to crawl inside under the wheel arch) We remove the wheel arch liner, of course, if there is one, then we unscrew the washer reservoir, it is screwed with 3 bolts, from the bottom 2 and under the hood 1. Now we carefully move the washer barrels to the side ... disconnect the connector from the electronic unit Under the abs electronic unit itself there is a return pump connector, we also remove it ... If you have a T20 torx, it is better to unscrew 6 screws with them, then remove our ABS electronic unit from the valve body Now we arm ourselves with a cutter or something similar and carefully cut off the cover block, (we scratch a little along the plastic case, along the entire perimeter, we make grooves in the lid at the end, as in the figure). Approximately its thickness is two millimeters. When you poke the whole thing through))), then take a flat screwdriver and try to pry off the cover, only on the side where the connector is, and on the other.With such movements, we will break it off from the body. When you break off, then inside you will see the board itself, filled with some kind of crap that looks like jelly ... We don't pick anything there, there are very small radio components on the board and God forbid that you hook it ...The dimensions of this box are 70 x 83 mm.Now, just to be careful, take scotch tape and glue a part of the electronic board, leaving only the place where the pins on the board connect to the pins on the pad of the block itself. Approximately in the middle of the pads there are two thick wires that connect the board to. contact pads on the block body. Now if you take, for example, a needle and slowly shake those two wires, then you will see poor contact ... (in most cases from the side of the case) So we found the problematic place that most ABS units suffer from, now we take a soldering iron and solder all the joints ...Just remove the jelly first, carefully and slowly ... If the place cannot be soldered normally, then take a wire about ten centimeters thick and about 0.3 thick and solder it. Cut off the rest of the wire as you solder it.I hope that you will be more careful ... When finished with the soldering of the wires, then you can check the performance of our unit directly. disassembled, so to speak, you just need to attach its electronic part to the valve body, do not screw anything, connect the connectors and turn on the ignition.If everything is in order, then there is no buzzer and the lights show. that everything is in order, then you did everything right ... Now it remains only to collect everything, and glue the lid with some kind of eboksidka. That's all there is to it, I think that such a repair is within the power of everyone ... Good luck.HOW NOT TO REPAIR ABS BLOCKS In this section I will post photos with brief comments. Since renovation. repair is different. masters are not the same. But to repair it like that! Better not to get to work at all.Since in the end you will still have to redo the work. but sometimes it is simply impossible to correct errors. ABS block with V70 1998 release. And so the lazy master got caught. who decided to simplify the repair technology utterly.Why pick out the entire block cover, he thought. took a hacksaw and sawed off a piece in the part where the connectors are. But the man did not think about that. that there is a special valve in the cover that prevents condensation from forming in the unit.Protecting printed wiring from destruction. And in addition he violated the tightness of the case. Which of course I tried to restore by treating the seam after repair with a sealant. But the U-shaped seam of the case is one thing.Other. just cover the hole from the hacksaw blade with a layer of sealant. Time will tell in any case. The block cover, instead of silicone sealant, was planted on epoxy resin. The next option was with a cold weld landing. Guys! Why scoff like that?If you do this FOREVER. solder all problem points. And then at least weld the block in this resin or pour it over with cold welding. All blocks that were repaired with such a putty, only the hydromodulator connector is soldered. And solder the main connector, sensors and data bus. power supply unit?If you are going to do it, do all the work. And do not hope that the unit will be brought back to you for repairs even then. There are no photos. The printed circuit board was filled with silicone sealant, after soldering the connector pins.As a result of the reaction of acetic acid contained in the sealant, the printed circuit board completely deteriorated. The tracks and radioelements were eaten by the acid. Block in the trash. This is how they sent me a block from the city of Tula. The block, as you can see, is completely disassembled.The reason for this disassembly. permanent error on the front ABS sensors. The problems were not only in the ABS unit. but also in the car itself.

open circuit of printed wiring from 3 ABS sensors (including 2 front ABS sensors, and one rear left). Broken wire and missing connector of the front left ABS sensor. Lost contact at the wiring connection points from the front ABS sensors. ABS, connected the wires of the left and right sensors to each other. Thus, disrupting the correct operation of the unit.

When power is applied to the ABS unit, the software checks all sensors and actuators. A reference voltage is supplied to all sensors within a few seconds, and the serviceability of the electrical circuit and the ABS sensor itself is revealed by its level.But even if a miracle happened and the block started working, it’s scary to think what would happen during emergency braking. In this case, it was possible to get full unlocking of the front axle wheels, which inevitably led to an accident. What was done you see in the photo.

On the left side is my block (reference, so to speak). the right one that had to be restored. Torn conductors were repaired with MGTF wire and fixed with hot melt glue. The cover from the block was missing.According to the new owner. there was also no second part of the lid, a narrow half. apparently the previous renovation was done like this. as shown in the photos above.Website for cars and repair.Like any other system in a car, the ABS periodically requires maintenance, preventive maintenance and repair.Of course, all the electronic units of this useful system are well protected from external influences and rarely fail, but every motorist should be prepared for the fact that sooner or later they will have to roll up their sleeves and start preventive or repair work. Periodic self-diagnosis is not canceled even by the presence of a self-test system in each car.It is necessary to pay attention to the prevention of ABS, since it performs a very important function in the car - it prevents the complete blocking of the wheels during braking. This, in turn, not only reduces the braking distance, but also allows the driver to maneuver during braking - without ABS, with locked wheels, any steering movement will lead to an uncontrollable skid of the vehicle, the consequences of which can turn into a disaster.It is quite natural that do-it-yourself ABS repair is possible only if the problem is accurately identified. Any car with an anti-lock braking system also has a self-test mechanism that is activated when the ignition is turned on. If the system is faulty, an error code is displayed on the on-board computer. Having looked at the instruction manual, the driver will easily understand the current problem and appreciate the possibility of self-repair.The entire anti-lock braking system can be conditionally divided into a central part, which includes electronic and hydraulic units, and a peripheral part, which includes wheel sensors. It is they who most often become the culprits of failures in the operation of the ABS. The second most popular cause of problems is worn wiring and poor connections that are unable to ensure the integrity of the electrical circuit.The main part of the ABS is the electronics and the hydraulic unit. They fail quite rarely, and their self-repair is highly undesirable without the appropriate equipment and qualifications. If the reason for the interruptions in the wiring, terminals or the sensors themselves, which are installed on each hub, it is quite possible to do without a visit to the car service.If it is almost impossible to repair the ABS unit with your own hands, then the wires and sensors are completely at the mercy of the driver. If the ABS indicator lights up frequently while driving, the first step is to check all the wires leading from the unit to the sensors. They should not have strong creases, damage to the insulation. If there are bare areas, such wiring must be urgently replaced - it is better to spend a little time on this than to find yourself in a critical situation without the help of the ABS.The next step in self-troubleshooting of the ABS will be checking the sensors. To accurately determine their performance, you will need a multimeter, with which the resistance is checked on each of them. The normal values of this indicator can be clarified in the car operation manual - for each system it can differ significantly. To check, you need to either lift the car with a lift, or alternately jack up each wheel.Each sensor is a fairly simple induction coil, so there is no difficulty in understanding whether it is functional or not - if the resistance does not correspond to the standard, the sensor must be definitely replaced. The cost of a new one is low, the sensor cannot be called a deficit either, and the procedure for self-replacement is not difficult even for a novice car owner.Normally, after turning the ignition key, the ABS indicator on the dashboard should light up, and after 3 seconds go out - this indicates a successful self-test and no problems. If it continues to burn, or lights up while the car is moving, it is advisable to perform the following steps:

park and turn off the engine;

try to start the engine again after 3-5 minutes;

check the voltage at the output of the battery with a multimeter - its minimum value should be 10.5 V;

check the quality of the contact of the power wires, as well as wires leading directly to the ABS sensors on the wheels.

To do the above, it will take no more than 5-7 minutes. If after a cursory check of violations it is not possible to identify, you will have to seek help from professionals, or do it yourself, having spent a lot of time checking each sensor.As practice shows, more than 80% of ABS malfunctions are associated with sensors located on the wheels. They have to work in very unfavorable conditions, therefore, periodic problems that arise in their work are more likely a pattern. When starting to repair ABS with your own hands, you can go in two ways - just replace the sensors with new ones or restore the old one to work. In the latter case, you will have to rewind the coil located inside the sensor - this is a difficult and painstaking job, and without skills, a positive result is not guaranteed.

Video (click to play).

It is much easier and more reliable to replace the sensor. To do this, you need to remove the old one, which is attached to the hub with one bolt. To get to the attachment point, you will need to dismantle the wheel, remove the caliper and brake disc. To make it easier for yourself to remove the sensor, you can pre-treat the mounting area with WD-40. Install a new one in reverse order. Repair of the anti-lock braking system, in addition to replacing the sensor, should also include checking the wires; if damaged, they should also be replaced. Otherwise, even a new sensor will not be able to ensure the uninterrupted functioning of the system, and the slightest short circuit will lead to its immediate shutdown.