DIY vaz engine ECU repair

In detail: do-it-yourself repair of a vaz engine ECU from a real master for the site my.housecope.com.

The engine control unit (ECU) is the brain center of the entire car, it consists of a large number of the most complex connections. With the help of this device, the functions of all elements of the power unit are monitored and coordinated.

Control devices installed on various car models are made of high quality materials, high technologies are used in their manufacture, ensuring high-quality assembly of electronic circuits.

But even the highest quality ECUs are prone to breakdowns and often need urgent repairs.

The design of the ECU is divided into main parts: the main unit, control sensors, actuators of the engine elements. The electronic control includes many special elements:

Malfunctions of the engine control unit lead to an imbalance in the operation of all vehicle systems.

The ECU uses the signals sent by the sensors installed on the powertrain to adjust the composition and amount of fuel entering the engine. In the course of its activity, the engine operating mode is set and the exact dosage of fuel mixtures takes place.

As a result of the controller functioning, the engine operation is stable both in cold and after warming up. It is impossible to start the motor if there is a breakdown in the ECU or if its control signals are absent.

Powerful transistors that are part of the control unit control the operation of the following actuators of the engine and fuel system:

ignition coils of the injection system;
idle speed valve;
electric nozzles;
fuel tank ventilation valve;
electromagnetic coils - solenoids;
turbocharging;
intake-exhaust system;
recirculation of exhaust gases;
cooling system.

Video (click to play).

The electronic device is an integral part of the on-board equipment of the machine; it is in constant information communication with such important systems:

Anti-blocking system.
Automatic transmission.
Stabilizing system.
Vehicle security system.
Cruise control.
Climate control.

When using this device, the most important parameters are optimized:

fuel consumption;
engine oil consumption;
power characteristics;
torque that affects the acceleration of the car;
the amount of toxic components in the exhaust gases.

The sensors send information to the controller in the form of digital signals. The control and functional calculation modules included in the software analyze the sensor signals and correct the operation of the actuators. Output signals during the adjustment process can even bring the diesel engine to a complete standstill.

When making significant changes in the design of the power unit (tuning), it is possible to reprogram the electronic engine control unit.

The integration of all control units into a common system is carried out using a special bus.

Situations often arise when car owners are faced with the need to repair the engine control unit. Carrying out this type of work with your own hands is possible with certain qualification skills.

Malfunctions in the operation of the control device occur due to a violation of contacts with sensors that monitor the functioning of the engine's working systems:

Anti-lock braking system (vehicle braking control).
Ignition block.
Injector controller.
Throttle position.
Temperature range of the engine.

Mechanical damage, water ingress on the parts of the microcircuit, failed attempts to repair the device with your own hands also lead to breakdown of the electronic control unit.

Loss of contact with the sensors occurs due to the lack of electricity, which indicates the occurrence of an internal malfunction that requires mandatory repair. Signs of lack of contact can be the following:

data is not received from the scanner;
messages contain incorrect parameters;
the control lamp "check" does not light up when the ignition is turned on;
lack of information about unstable engine operation.

Timely identification of defects and repair of electronic engine control units will prevent a stop in the operation of systems, assemblies, and vehicle assemblies.

The list of the most likely causes includes the following factors:

Microcracks in the circuits and body of the device caused by mechanical stress (shock, strong vibration).
A sharp rise in temperature, leading to overheating of the motor control unit.
Destruction of ECU elements under the influence of corrosion.
Penetration of moisture into the controller case due to depressurization.
Illiterate repair actions.
Applying the "lighting" effect while the engine is running to help the neighboring car.
Changing the position of the terminal connections while connecting the battery.
Lack of power bus connection when the starter is turned on.

The efficiency of the ECU fully depends on the listed factors, many of which are capable of causing significant harm to the control device.

To prevent permanent damage, it is necessary to carry out regular diagnostics of the electronic engine control. In order to save on expensive repairs and complete replacement of elements of the electronic control system, the check is carried out at least once a year.

Malfunctions in the engine control unit are indicated by the following vehicle malfunctions:

problems with starting the engine;
tripping the engine;
the appearance of thick smoke;
decreased response to the gas pedal;
interruptions in connection with the ECU;
loss of control over turning on and off the engine fan;
malfunctions of the ignition coils;
failure of fuses;
sensors are not sending signals.

Thanks to the self-diagnosis system built into the ECU, you can check and determine the degree of damage with your own hands. To carry out diagnostic measures, you need to connect to the device using a laptop with an installed program designed to work with diagnostic data. Instead of a laptop, you can use special testers, oscilloscopes.

The data obtained during the measurements are compared with the indicators that are standard.

The causes of damage to the engine control unit are divided into two main types: faulty conductor or firmware failure. The firmware is restored only with the help of specialists in the service center. You can check the electrical parameters with your own hands using a special measuring device - a multimeter.

To search for a breakdown in the wire, you must familiarize yourself with the control device diagram. Having studied the location of the conductors, resistors and power supply, it is the turn of the "continuity" of the electrical circuit in the place where the error in the readings of the electronic unit is detected. In the absence of such information, it is necessary to check the wires throughout the circuit.

To repair the engine ECU, the following operations are required:

Locate the breakdown location.
Re-measure the resistance.
Find the attachment points of the conductor.
Attach in parallel a wire with the required resistance using a soldering iron; it is recommended to leave the old wire in place.

After the measures taken, the system should work stably. If the ECU errors repeat, contact the service center.

The durability, safety and reliability of the vehicle depend on the timeliness of the repair of the engine control unit.

The electronic engine control unit is rightfully considered one of the most important parts of the car. This device is not in vain called the "brains" of a car, because it is entirely responsible for the stability of the operation of almost all vehicle systems.

Every year more and more cars appear on the world market, the reliability and durability of which directly depends on electronic systems. Absolutely all manufacturers are trying to equip cars with the latest ECU models. Along with this, the mechanical components in the car are becoming less and less.

Be that as it may, the use of electronics in the automotive industry is fully justified. ECM manufacturers place great emphasis on the quality of materials and the assembly of their products. That is why the “brains” of a car are extremely rare. But as they say, nothing lasts forever. And even a high-quality ECU will fail sooner or later.

In a wide range of specialists, a list of the most common reasons for which an ECU breaks has long been compiled. These include:

mechanical damage. The engine control unit is damaged from shocks and strong vibrations, which contribute to the appearance of microcracks in its circuits and housing;
sharp jumps in temperature, as a result of which the engine control unit itself overheats;
corrosion;
depressurization and ingress of moisture into the ECU case;
interference in the work of a block of people who do not have the necessary skills;
the so-called "lighting" from a car with a running engine;
rearrangement of terminals when connecting the battery;
starting the starter without a connected power bus.

All of the above factors affect the efficiency of the engine control unit in different ways. Some of them cause minor harm to the “brains” of the car, while others can instantly break the block. Fortunately, there is still a way to prevent the final breakdown of the unit - ECU diagnostics, which should be performed at least once a year.... This is the only way to save on expensive part repair or complete replacement.

Many drivers believe that only professionals should be engaged in checking the operation of the engine control unit. In fact, almost every “brain” at the factory is equipped with a built-in self-diagnosis system. With its help, it will not be difficult for even an inexperienced driver to identify any malfunctions with their own hands.The engine control unit is a mini-computer that must perform specialized tasks in real time. The latter can be divided into 3 categories:

processing signals from sensors;

calculation of impacts to control vehicle systems;

adjustment of the operation of executive mechanisms.

To start checking the status of the engine control unit, we need to connect to it. This can be done using a special tester or laptop. On the latter, a program designed to read diagnostic data must be installed in advance. Modern cars are equipped with various ECU models. We will consider the implementation of diagnostics of the engine control unit using the model as an example Bosch M 7.9.7... These are the “brains” that are installed on the latest car models. VAZ and many foreign cars. Image - DIY vaz engine ECU repair

We will carry out diagnostics with our own hands using a free program KWP-D... In addition to the utility, we need an adapter that supports the protocol KWP2000... We start diagnostics by connecting the adapter. We insert one end of it into the ECU port, and the other into the laptop. After that, turn on the car ignition and start the program.A message should appear on the laptop display stating that the operation to check for errors in the operation of the ECU has begun successfully. After that, we will see a table with the most important parameters of the machine.

It is necessary to pay attention to the DTC section, which contains all the errors issued by the engine. If there are any, then go to the "Codes" section, where we will see the decryption of all existing failures. If you did not find any errors, then the engine is in perfect condition.

Other sections of the table should not be ignored either. The information in them is equally important. So, the UACC parameter is responsible for the state of the battery. Normal readings for this section are in the range of 14-14.5 V. If the voltage of your battery is less - it is worth carefully checking the electrical circuits. Another important parameter is THR, which is responsible for the position of the throttle valve. During normal idling, the throttle position sensor will read 0%. Otherwise, you should contact a specialist.

Another important indicator that interests all drivers is the QT parameter, which is responsible for the amount of fuel consumption. At idle speed, the section should contain figures of 0.6–0.9 l / h. For a more accurate diagnosis, you will need to check the voltage in the car spark plugs. When checking all these indicators, drivers very often ignore the state of the crankshaft during rotation, for which the LUMS_W section is responsible. If the numbers in it are more than 4 rev / s, this is a sign of uneven ignition in the cylinders. It is also worth checking the high voltage wires and candles.

Diagnostics and repair of ECUs is not at all difficult. However, as with any business, you should always be prepared. In the case of a brain test, it will be enough for us to purchase inexpensive devices. They will help you do all the work yourself. The first thing every driver needs to have is an oscilloscope. This device provides the necessary information about the operation of all vehicle systems.

The received data is displayed in numerical or graphical form. With the help of an oscilloscope, we can compare the available numbers with standard indicators. The cost of the device is in the region of 2-5 thousand rubles. Another important device is the motor tester. It is designed specifically to determine the performance of electronic engine systems. With its help, you can get information about the drop in revolutions when the cylinders are turned off and the discharge in the intake manifold. The price of the device ranges from 3 thousand rubles.

Do you still think that car diagnostics is difficult? If you are reading these lines, then you have an interest in doing something yourself in the car and really savebecause you already know that:

STO lomat big money for simple computer diagnostics

To find out the error, you need to go to the specialists

Simple wrenches work in the services, but you can't find a good specialist

And of course you are tired of throwing money away, and there is no question of driving around the service station all the time, then you need a simple ELM327 AUTOSSCANER that connects to any car and through a regular smartphone you will always find a problem, pay off CHECK and save a lot.We have tested this scanner ourselves on different machines. and it showed excellent results, now we recommend it to EVERYONE! So that you do not fall for the Chinese counterfeit, we publish here a link to the official website of the AutoScanner.The ECM is the brains of the vehicle. With its help, the main processes that ensure the normal operation of the power unit are produced and controlled. You can learn more about how diagnostics, as well as home repairs, of the engine control unit are made from this material.Before you repair the engine control unit in your car, you need to be sure that the manifestation of breakdowns is associated precisely with its work.According to many of our compatriots, the repair of electronic engine control units should be carried out by specialists. But do not forget that almost all ECUs are equipped with a self-diagnosis system, which allows you to easily identify system malfunctions. Image - DIY vaz engine ECU repair

Repair of the motor control unit

To diagnose the ECU with your own hands, you will need to connect to the device, for this you will need a special tester or computer. If you are using a laptop, you must install the appropriate verification software on it in advance. On many domestic VAZs, as well as foreign cars, a Bosch engine control unit is installed, using this device as an example, you will consider the verification procedure. For diagnostics, you need the KWP-D utility (you can use any other, we took this one as an example). In addition to the program, prepare an adapter that must support the KWP2000 protocol.

The diagnostic procedure begins with connecting the adapter - one of its outputs must be connected to a port on the unit, and the other to a computer.
Turn on the ignition and run the utility. A message appears on the computer screen to start the error checking procedure.
Further, you can see a table in which the main parameters of the car's functioning are marked. Pay attention to the DTC category, all errors that are in the operation of the machine's motor are marked here. If they are present, then in the "Codes" section you can decipher these errors.

You also need to pay attention to other sections. For example, the UACC indicator is responsible for the functionality of the battery - ideally, its parameters should correspond to 14-14.5 V. If the voltage level is lower, it is necessary to diagnose the wiring. The THR parameter is responsible for the performance of the choke, if the device is working normally, then it should be 0%. The QT parameter is responsible for the volume of fuel consumption; at idle, this indicator should correspond to 0.6-0.9 liters per hour (the author of the video is the AlexBrooy channel).

Repair of vehicle control units should be carried out in the event of a malfunction.

Before removing and disconnecting the faulty ECU, let's look at the main causes of breakdowns:

Repair of the engine ECU can be carried out in the event of mechanical damage. The brains of a car can be subject to vibration and shock, as a result of which cracks can form on the body of the device and the board.
Temperature differences can also be the cause of a car's ECU malfunction, which contributes to overheating of the device.
Corrosion and exposure to aggressive environments on the device.
Moisture - if it enters the housing, it may require replacement of the vehicle ECU. Often it is not possible to make repairs after moisture has entered the structure. The reason for the ingress of moisture into the device may be the depressurization of the housing elements.
As experts note, quite often the need for repair arises as a result of interference in the work of the "brains" of inexperienced repairmen.
Lighting the battery from the car with the engine running.
Replacing the engine control unit may be required if the “+” and “-” terminals were swapped when connecting the battery.
Another reason is the inclusion of the starter in the absence of a power bus connection (video by Ramil Abdullin).

We will also consider the signs of a malfunction of the car's ECU, which will allow us to determine the breakdown of the device:

The engine does not start, smokes, possibly knocking.
Motor skips.
Dips, when you press the gas pedal, the car may not respond.
There is no connection with the "brains".
The control lamp of malfunction of the engine management system is on. It may be a Check Engine light, but in some cars, the unit health indicator is used separately.
The cooling fan turns on randomly.
The safety elements burn out regularly.
Controllers and sensors stop signaling.

Before removing the control unit and disassembling it, inspect the connector of the device, it may be damaged.

The repair procedure is described using the example of a BMW ECU:

How to replace the engine control unit with your own hands - see the video below (video by Sergey Kitaev).

We check the ECU with our own hands
1. Reasons for ECU failure: what should you be prepared for?
2. How to check the ECU: practical advice for motorists who do not want to go to the workshop.
3. What is needed to check the ECU, or how do professionals cope with this task?

A modern car is partly a computer on wheels, or to be more precise, a computer that controls the movement of the wheels. Most of the mechanical parts of the car have long been supplanted, and if they remain, then they are completely and completely controlled by the "electronic brain". Of course, it is much easier to drive a computerized car, and the designers think about the safety of such cars first of all.

However, no matter how perfect the design of electronic control units (ECU) is, they can still fail. The situation is not the most pleasant, and due to the complexity of the device, there is no need to talk about self-repair (although there are such craftsmen). In today's article we will talk about what kind of malfunctions can happen to the ECU, how they can be caused and how to diagnose them correctly.

First of all, an electronic control unit for a car, or simply an ECU, is a very complex and important computer equipment. In the event of a malfunction of this device, incorrect operation of all other automotive systems may appear. In some cases, the car may stop working altogether, including the failure of the transmission, chargers and control sensors.

Electronic blocks are different and can control different devices. At the same time, all systems still actively interact with each other and transmit important information for adjusting all functions. The most basic of these is the car engine ECU. Despite its constructive simplicity, it performs a lot of complex tasks:

1. Control of fuel injection into the combustion chamber of the vehicle.

2. Throttle valve adjustment (both while driving and while the engine is idling).

3. Ignition system operation control.

4. Exhaust gas composition control.

5. Valve timing control.

6. Coolant temperature control.

Speaking specifically about the engine ECU, all the data it receives can also be taken into account during the operation of the anti-lock braking system, and during the operation of the passive safety system, and in the anti-theft system.

The reasons for the failure of the ECU can be very diverse. In any case, this does not bode well for the car owner, since this device cannot be repaired. Even at service stations, they simply change it to a new one. But, be that as it may, it is necessary to understand in great detail what can cause a breakdown. Thanks to this knowledge, you will be able to ensure the maximum possible protection of your device from such troubles in the future.

As noted by auto electricians, most often the ECU fails due to overvoltage in the electrical network of the car. The latter, in turn, can occur due to a short circuit of one of the solenoids. However, this is not the only possible reason:

1. Damage to the device can occur due to any mechanical impact. It can be an accidental shock or very strong vibrations that can cause the appearance of microcracks in the ECU boards and the soldering points of the main contacts.

2. Overheating of the block, which most often occurs due to a sharp temperature drop.For example, when you are trying to start the car at high revs in severe frost, squeezing the maximum out of the capabilities of the car and all its systems.

3. Corrosion, which can occur due to changes in air humidity, as well as due to the ingress of water into the engine compartment of the car.

4. Moisture penetration directly into the control unit itself due to depressurization of the device.

5. Intervention by strangers in the device of electronic systems, as a result of which a violation of their integrity could occur.

• If you wanted to “light a cigarette” from the car without first turning off the engine.

• If the terminals were removed from the car battery without first turning off the engine.

• If the terminals were swapped when connecting the battery.

• If the starter was turned on, but the power bus was not connected to it.

However, whatever the cause of the ECU malfunction, any repair work can be carried out only after a full professional diagnosis has been carried out. In general, the nature of the device malfunction will tell you about malfunctions in other systems. After all, if they are also not eliminated, then the new control unit will burn out in the same way as the old one. That is why, in the event of an ECU burnout, it is very important to establish the true cause of the breakdown and immediately eliminate it.

But how can you determine that the control unit has really failed, and not some other system? This can be understood by a number of the very first signs that may appear in such a situation:

1. The presence of obvious physical damage. For example, burned out contacts or conductors.

2. Inoperative control signals for the ignition system or the gasoline pump, the idle mechanism and other mechanisms that are under the control of the unit.

3. Lack of indicators from different sensors monitoring systems.