Repair of brain cars. Diagnostics of the ECU - work, not tolerant. How to determine that the engine requires the repair of the electronic unit

The car control unit is, this is, in fact, the "brains" of the car, from which all car systems depend on. A number of factors indicate a malfunction of the control unit, but it is possible to determine exactly what it faced in the control unit, only with high-quality diagnostics.

1 Diagnostics of the engine control unit

To diagnose, you need to contact a specialized car service, in which, with the help of a special module and cable, specialists connect to the control unit and make it diagnostics. The module is connected to a special computer on which the program recognizes the error codes that are displayed on the screen during the diagnosis of the control unit. If necessary, specialists also use multimers.

Thus, the specialist records various indicators in real time. It can determine the situation throttle valve, Fuel coefficients or, for example, temperature. The implementation of the diagnostics for various models of modern cars is not much difficult, in addition, the computer firmware is constantly updated, which means that the computer receives new data on new types of control blocks. After the diagnostic procedure revealed errors, the specialists start repairing the engine control unit, replacing or restore the factory settings, throwing the errors that appear.

Engine ECU repair is a rather complicated and time-consuming process and is recommended solely in cases where the replacement of the control unit is impossible for any reason, or when the replacement can be too expensive for the car owner. It is not recommended to repair the computer at all, there is a big risk of damaging the electronic "brains" finally, which will invalid all the associated car systems.

2 Possible causes of engine control unit malfunction

The reasons for which the electronic control unit fails or begins any failures in its work, there are a huge set. Among the most common breakdowns, it is possible to distinguish such as the absence of a review of the ABS sensor, the lack of contact with the ignition unit, the injector operation controller, as well as the absence of contact with different sensors, the position of the choke or the temperature sensor. In addition, the control unit may fail as a result of mechanical damage or moisture from entering the chip. Thus, in the event of a malfunction in the block, overvoltage may occur, which sometimes completely displays the system. Overheating, moisture getting, rust, moisture - all this can cause the breakdown of the electronic unit. Also, specialists of numerous car services celebrate a high proportion of appeals to them motorists who tried to repair the control unit with their own hands or trusted this business to unprepared people.

It is important to remember that the computer consists of a plurality of complex compounds, and therefore poor-quality repair can provoke serious problems in the work of this unit. As for new car models, in case of problems with the control unit, it is recommended. full replacement of this element. If the car is warranty, then you should contact a dealership center, where it will be made to a new one, while there are some car models, the repair of the engine control unit is not possible even by professionals. In any case, it is worth first to conduct high-quality diagnostics, then consult with a specialist, and only after that decide what exactly to do with the failed control unit.

Electronic motor control unit is "brains" vehicle. With it, the main processes ensure normal operation are made and controlled. power aggregate. In more detail about how diagnosis is made, as well as repair at home engine control unit, you can learn from this material.

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Diagnosis of EBU

Before repairing the engine control unit in its car, it is necessary to be sure that the manifestation of the breakdown is connected with his work. According to many of our compatriots, the repair of electronic control units should be carried out by specialists. But do not forget that almost all the ECU is equipped with a self-diagnostic system, which allows you to determine the system malfunctions without any problems.

To produce, you need to connect to the device, for this you need a special tester or computer. If you are using a laptop, you need to install the appropriate software using the appropriate software to check. On many domestic vasesAlso foreign cars, the Bosch engine control unit is set, on the example of this device you will consider the test procedure. To diagnose, you will need the KWP-D utility (you can use any other, we took this for example). In addition to the program, prepare the adapter that must support the KWP2000 protocol.

1. The diagnostic procedure begins with the adapter connection - one output must be connected to the block port, and the other with the computer.
2. Turn on the ignition and run the utility. The computer will appear on the start of the verification procedure for errors.
3. Next, you can see the table in which the main parameters of the functioning of the car are noted. Pay attention to the DTC category, all errors that are in the operation of the machine are noted here. If they are available, then in the "Codes" section you can decipher these errors.

It is also necessary to pay attention to other sections. For example, the UACC indicator is responsible for the functionality of the battery - ideally its parameters must correspond to 14-14.5 V. If the voltage level is lower, it is necessary to diagnose the wiring. For the performance of the throttle, the THR parameter is responsible if the device works normally, then it should be 0%. For the volume of fuel consumption corresponds to the Qt parameter, on idling This indicator must correspond to 0.6-0.9 liters per hour (author of the video - ALEXBROOY channel).

Characteristic block malfunctions

Repair of car management blocks should be carried out in case of malfunction.

Before shooting and disconnecting a faulty ECU, let's figure out the main causes of the breakdown:

1. Repair can be carried out in the event of mechanical damage. The "brains" of the car may be subjected to vibrations and shocks, as a result of which cracks can form on the device housing and board.
2. The reason for the malfunction of the car, the temperature differences, which contributes to the overheating of the device.
3. Corrosion and impact of the aggressive environment on the device.
4. Moist - Her hitting to the body can lead to the fact that it will be necessary to replace the car. Often produce repair after moisture getting inside the design is not possible. The cause of moisture to enter the device can be the depressurization of the hull elements.
5. According to experts, quite often the need for repair arises as a result of interference with the work of "brains" of inexperienced repairmen.
6. with engine on.
7. Replacing the engine control unit may be required if the "+" and "-" terminals were confused when connected acB.
8. Another reason is the inclusion of the starter in the absence of a power bus connection (the author of the video is Ramil Abdullin).

We will also consider signs of a car malfunction, which will allow you to determine the device breakdown:

1. The engine does not start, smoke, detonation is possible.
2. Skip when the motor operation.
3. Dips, when you click on the gas pedal, the car may not respond.
4. Communication with "brains" is absent.
5. The engine control lamp is burning. It may be a light bulb Check EngineBut in some auto separately the block performance indicator is used.
6. The cooling system fan is turned on arbitrarily.
7. Safety elements regularly burn out.
8. Controllers and sensors cease to feed signals.

Instructions for troubleshooting do it yourself

Before removing the control unit and disassemble it, inspect the device connector, perhaps there are damage.

The repair procedure is described by the example of the BMW ECU:

1. Using a screwdriver, you need to beat the petals on the device cover, after which it is easy to dismantle it.
2. After that, on the reverse side of the design, unscrew the bolts fixing the housing.
3. Disagreeing the case, you can see a diagram of a device with soldered outputs.
4. As practice shows, one of the most common causes of the brain breakdown is the cold soldering of contacts of the radio components. In other words, all contacts are soldered, but a small crack on the solder itself may appear around them. That is, the soldering seems to be, but in fact there is no. For diagnostics you will need a magnifying glass. If during the check you will notice badly soldered conclusions, you will need a soldering iron.
5. Further, you need to pay attention to the diagnosis of transistors and chips, there may be a squeak on these components. If there is a way, these components will need to be replaced.
6. In the event that there are no rejarms on the board of the device or damage, then you will have to look for the device components failed. Namely, we are talking about Transistors of Darlington. This component is a composite transistor, which, in turn, consists of two transistors. If you have suspicion of its performance, this fee should also be replaced.
7. The last thing to pay attention to is a quartz resonator, also installed on the scarf. As a result of vibration, this element may fail, which, in turn, can lead to the failure of the fixed frequency generator device.

Video "Replacing ECU on the example of Mitsubishi Pajero car"

How do you replace the engine control unit with your own hands - look at the video below (the author of the movie - Sergey Kitaev).

Repair of the engine control unit today can be done yourself, if you have small electronics repair skills.

Electronic motor control unit, abbreviated ECU is electronic devicewhich using various signals from the engine sensors controls the composition and quantity of fuel supplied to the engine.

With the help of sensors, the engine operates very thinly and doses very accurately fuel mixture. In this case, the engine is stable as immense and heated. But if it fails, you will not be able to start the car engine.

The unit of the computer consists of microcircuits, transistors, capacitors and resistors. All these elements may fail at any time. The control unit with powerful transistors (composite transistors of Darlington) controls the ignition coil or several coils, depending on the injection system, as well as the turnover valve idle move, electrical nozzles, valve ventilation fuel tank, various solenoids, etc. At the failure of any of them, we lose the control signal with a one or another actuator.

I want to give an example one story. I had one friend car BMW. 3 series. M-40 engine with 1.8 liters. Once, he went to visit to relatives in the neighboring village and decided to peck a little on the highway. I pressed the gas pedal almost to the polik and began to accelerate, but just did not have time. I caught a "good" fossa on the asphalt and then clicked on gas more from the surprise. The car rooted and ... stalled.

How many starter he no longer twisted, did not start. Only the battery put. They dragged him to the cable home and his torment began with finding the cause. In short, many masters were pushed and could not find anything really, but rather found the absence of sparks. From the words of the owner, the ignition coil, high-voltage wires, the distributor also looked, could not see anything suspicious.

Well, I decided to ask me, maybe something I know about this. Honestly to confess I did not have a special desire to mess around with the car. Repair of machines Although promising today is a lesson, but I do not have for this conditions. The garage is not first. It is necessary to build, but there is not enough money to build something worth it. Anyway…
Assessed with me the devices (multimeter, oscilloscope, from the Avtodata program pulled the electric circuit in the injection), the tool and went to the garage where the car was stood.

To begin with, it was connected parallel to the ignition coil with a light bulb at 12 volts and scrolled the engine starter. The lamp barely flashed, but should blink in full. As this engine The ignition coil control switch did not have, then the coil control took place from the engine control itself.

For reliability, measured the digital multimeter on the engine control unit connector signals from sensors according to the map specified in the AUTODA program. All signals were normal, which ultimately led to the perpetrator of a malfunction - ECU. To do this, a disassembly of a block from a car followed by its disassembly. Thus, on the board defined the output transistor of the Darlington, which connected one output of the ignition coil on the mass of the car.

Using the oscilloscope measured the signal form on the transistor collector. It was an irregular shape with strong distortions. On the basis of the transistor, the signal was correct form. This determined the culprit in the absence of spark. Analog was bought and soldered into place. After that, the car started. Here it happens.

Attention!

We carry out the repair of control units in Kazakhstan in p. Irtysk. It is possible to send a faulty control unit by mail. We repair and send back. Turn off the car immobilizer. To do this, you send or bring us a motor control unit, restore SRS blocks (airbag), clean from collision data. Contact information on e-mail: [Email Protected], wat sap +77058715032

Examples can be brought a bunch, but let's give the main actions to search for ECU faults. Repair of the ECU should be started after full confidencethat the control unit itself is to blame.
And so what to do if the car stopped starting.
1. Check if there is a spark, fuel injection and whether the fuel itself is supplied from the gas tank.
2. If the pump serves fuel, the fuel injection is there, and there is no spark, then check the ignition coil control switch for service. This is done by installing an obviously good switch. If the switch is not, then the coil control transistor is in the ECU itself. It must be checked.
3. If the spark is, but there is no fuel injection, then you need to check the transistor of the nozzles control into the ECU. If there is a ignition coil control switch, then check the control signal output from the switch to the ECU block. If the signal is not in this case, the ECU will not give the command to open the nozzle.
4. If there is no spark, no fuel injection, then you need to check the help of the Hall sensor or if it is not, the position sensor crankshaft. To do this, it is best to use an oscilloscope.
And so you concluded that the motor ECU unit is faulty. Remove it then with the car, only before you do not forget to remove the minus terminal from the battery.

For example, consider the ECU engine BMW.. Before disassembling it, carefully inspect its connector on visible damage.

Very often, contact conclusions are oxidized and covered with greens. And this in turn is bad electrical contact. And hence I. unstable work Injection systems in general. Using a screwdriver, remove the petals on the lid and remove it.

Further using a special tool. Unscrew the screws on the back of the ECU block.

You can take it carefully. Our gaze opens a view of the opposite direction of the printed circuit board with soldered conclusions.

Well, now about the main thing. The most common cause of the failure of the ECU unit is the "cold soldering" of the findings of radio elements. That is, the conclusion as it should be soldered, but a microscopic circular crack in the solder is formed around it. The element as it should be, but actually no. Take a good magnifying glass and carefully inspect all pCB. If you find unbelievous, then boldly take it for a soldering iron.
Second thing to pay special attentionThis is the evacuation of chip and transistors.

Such elements are necessarily subject to replacement.
If the rogarov and external damage is not detected at visual inspection, I proceed to the definition of faulty elements, in particular Darlington transistors. What is a transistor of Darlington.

This is a composite transistor of two transistors. How to check this transistor will be written in some of the following articles. Do not miss. Subscribe to blog updates to mail. Best of all instead of the dismantled transistor, install knowingly serviceable.

More on want to draw your attention. On the board there is a set quartz resonator, which with sharp blows can lose its performance. And this may cause the loss of the functionality of the fixed frequency generator.
Repair of the computer with your own hands very often compensates for the additional costs that you can incur in case your electronic engine control unit fails.

Watch video

I wish good luck in troubleshooting the ECU and its repair!

ECU (electronic control unit) is a device that controls the parameters of the mechanisms during operation. Usually, the abbreviation of the ECU is used in relation to the engine control unit.

In fact, in the car there are still control blocks brake system (ABS block), body control unit, which is often referred to as Body Control Module (BCM or BSI), climate control unit (climate control) and others.

Principle of operation

The principle of operation of the electronic engine control unit is built on a standard microcontroller architecture. Data on the parameters of the engine from various sensors is entered into the ECU, then processed (enhanced, digitized, encoded).

The main processing of data on a specific algorithm produces a microprocessor, which on the output bus gives signals to actuators. These signals are adapted (converted from numbers to analogue, amplified) and entered on the connectors of the electronic control unit.

The tasks solved by the electronic motor control unit include diagnostics of the main nodes. Modern ECUs can identify a variety of errors:

• lack of supply voltage on electronic engine nodes or low power;
• emboss of electrical circuits or short circuit;
• incorrect signals at the output of the sensors;
• ignition pass and injection;
• nonconformity of the ignition angles;
• and many others.

Errors are stored in non-volatile memory up to their deletion using diagnostic devices (valid errors cannot be removed without eliminating the cause of the error).

In cars earlier, errors could be removed temporary (about 15 minutes) by disconnecting the battery from the on-board network of the car.

The ECU together with the immobilizer blocks the operation of the engine in the event of unauthorized access. Each electronic motor control unit makes this function in accordance with the algorithm laid by the manufacturer.

Blocked can:

• ignition signal on the coil;
• fuel injection pulses;
• permission to launch starter and others.

In some cars, the engine can run for a few seconds and stuck.

For many control units, there are non-immobilizer firmware ECU (IMMOOFF). You can reflash the memory of the control unit and forget about the problems with the immobilizer, however, the car becomes more vulnerable from the point of view of the hijacking.

Scheme

The fundamental circuit diagram of the engine control unit itself is a production secret, and find it even for domestic cars Very problematic.

Therefore, the repair of the ECU is produced only by professional electronics high level. Usually in the control blocks fail the injection and ignition control transistors, the stabilizers of the reference stresses, firmware flies.

Specialists sometimes specifically change the software firmware in order to increase the engine pickup or reduce fuel consumption.

Video - ECU firmware M74:

To repair electronic engine nodes, an electrical connection circuit is required. Such a scheme can be found in the manuals for the operation and repair of cars, software and technical complexes of the type of Autodata and Tolerance.

For example, consider the organization of the Volksvagen Golf car engine control circuit 3 2001 release, engine MAGNETI MARELLI 1 AV.

Without deepening in the scheme, you can see that the camshaft sensor signals use as the ECU sensors, mass flow air, coolant temperature, oxygen.

The signal coming from the camshaft sensor is shaped:

As executive mechanisms, the ECU controls injectors injection signals, throttle drive, ignition to the coil switch:

ECU is associated with immobilizer, dashboard.

In order to check the electrical connections of the circuit nodes with an electronic motor control unit, it is necessary to know the location of the contact terminals (pinout), which is also provided in the reference books:

Where is the engine control unit

In cars, until the 90s of the release, the most rational location of the engine control unit was considered space in the cabin of the car near the left or right front counter in the field of the passenger's foot or driver. First of all, it was believed that these are the most secure places from the point of view of mechanical damage and moisture penetration.

Video - Transferring ECU on Kalina:

From the mid-90s, the engine control blocks put in the windscreen space. This is due to the following considerations:

• under the hood easier to search for electrical connections faults;
• all communications with engine sensors and executive mechanisms become shorter, therefore, more reliable;
• The computer has become more reliably defended by moisture with special sealants.

In the absence of reference books, you can easily find the electronic engine control unit, moving along a large wiring harness of the engine control system. It usually represents a small electronic unit in a metal casing with one or several connectors in the end part.

In many cases, gain access to the internal space of the block to electrical scheme Not easy: she is filled with compounds that need to be deleted. The fee, as a rule, contains a small amount of components.

Signs of malfunction of the EBU

Among the auto plays there is an opinion that electronic system The engine control fails to last. Moreover, it is not always possible to determine the malfunction of the engine control unit.

Indeed, the computer can digit about the nodes connected to it, but to diagnose their own performance in most cases it is unable.

What can indicate a malfunction of the ECU?

The most frequent signs of malfunction are constant burning of fuses, serving block Engine control. In the practice of operation, there are no discretion cases of connectivity rechargeable battery. In the ECU scheme there are protective diodes for this case. If they make their way, there is a short circuit for nutrition, which leads to constant burnout of the fuses. Faulty must be changed.

Also, a malfunction for nutrition can cause an ACB shutdown during engine operation. In this case, the control unit is powered only from the generator and, if it is faulty, a situation may occur incorrectly submitted to the voltage block.

It is impossible to remove the battery terminals on the running engine (!)How many car enthusiasts do when starting from someone else's battery.

How to check the ECU for performance

The first phase of performance testing is the control of all feeding voltages.

Second phase - computer diagnostics. If the diagnostic device is associated with the engine, this is already a sign of the performance of the ECU.

On the blocking of the block by the immobilizer, then you need to tie the keys.

In some cases, to determine the fault, you must disassemble the computer, that is, remove the sealant and remove the cover by getting access to the board. It can detect running conductive tracks, defective transistors, diodes and other elements.

The most reliable method of checking is to "throw up" an obviously good ECU. But it should be either a non-free or new to "tie" keys and immobilizer.

Sometimes on disassembly, a set of ECU + immobilizer + key chip is sold. In this case there are no problems. Connect to the ECU and immobilizer scheme, the chip is set to the end of the pump coil on the ignition lock, and then start the engine.

Additional protection

For more confident protection of the engine control unit from the reverse battery and can be installed on the supply circuits to install diodes (better powerful stabilizers with a stabilization voltage 15 - 17 volts) in reverse turning on.

Then the overvoltage and cake will lead to the failure of the fuses serving the power supply circuit of the ECU, the increased voltage or the inverse polarity voltage to the control unit will not pass, and this is the greatest danger.

In order to protect the ECU from climatic influences, it is necessary to monitor the quality of the sealant. After five years of operation, it is advisable to take measures to improve tightness, since the former sealant can refuse in conditions of elevated temperatures under the hood.

Video - Protection of the Renault Duster Engine Control Block (Logan, Largus):

You can not close access to the block with additional structures, lay the rag near it. This reduces the natural ventilation of the device, which in the process of the car heats up.

Replacing the engine control unit

If the control unit has failed, and it is not repaired, it should be replaced with a similar one with the same number indicated on the ECU housing.

Sometimes a small deviation is allowed in the room. For example, the change in the last two or three digits may indicate another volume of the engine or modification, which can practically do not affect the technical characteristics.

1) Repair of the control unit begins with a call to the company Raccoon.
2) Next, you explain the essence of your problem to our specialist.
3) Enter the control unit for repair or we can send the courier block.
4) We make diagnostics, we agree with you the timing and cost of repair.
5) Come and take a finished block or can you send a block by courier.

One of the main activities of the company Rota is the repair of the ECU (electronic control units), modern cars Their number can reach up to 15 and all of them are part of a single organism. And problems in one of the blocks are reflected at the work of the entire car. The reasons for incorrect operation of electronics can be different from moisture to errors in software The manufacturer, but most often the human factor is played here. Here you can attribute dampness in the car, improper exploitation, untimely maintenance Or operation of a car with faults.

The company's specialists have a deep understanding of the subtleties of the operation of automotive electronics, so we do even for complex malfunctions and use only original spare parts in the work. Apply to us for the diagnosis or repair of electronic control units, both a hundred and customers themselves and if in the first case the specialists of the service station can give detailed information about the faults, if the car owner is drawn to us, it is almost always of detailed information has no. But we always go to meet customers and try to help. We accept electronic control units for diagnostics and if necessary, we ourselves communicate with the specialists by electricians who serve the car of our client, to clarify the details of the problems in the electronic control unit. And such a joint work necessarily gives a positive result.

We repair electronic control units passenger cars, trucks, special equipment. Repair of any control unit begins with the analysis of the stated faults, it happens that we have already understood the control unit on the phone with the client, or in the event that the block is working, we give recommendations for checking and searching for malfunction in the car. If we understand that the electronic control unit is really not working, then after delivering it to us in the workshop, diagnose and coordinate with the client and the amount of repair. In most cases, for repair is enough 2-3 days. But in more complex cases, the repairs can reach 2-3 weeks, as the electronic blocks of car management are assembled on a special element base, delivery of spare parts from abroad takes some time. We use the services of only reliable and verified spare parts suppliers. Professional equipment, high-quality element base accumulated over the years of work unique knowledge, and a hot desire to help the client, here are the factors on which our work is built.