DIY car ECU repair

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

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.

Repair of the motor control unit

To diagnose the ECU with your own hands, you need to connect to the device, for this you 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.

Video (click to play).

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 fluctuations can also cause a car 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).

The engine control unit (ECU) is the brain center of the entire car, it consists of a large number of 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.

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.

As you know, a modern injection engine is fully controlled by an advanced ECM. The system includes blocks-controllers, sensors and executive electronic-mechanical devices. In this case, different control units are used for different engines.

Although these blocks are quite reliable devices, their breakdown cannot be ruled out. A short circuit, mechanical damage to the unit, ingress of moisture into the controller, etc. can lead to problems that are directly related to the ECU. One way or another, incorrect operation of the control unit will not allow the internal combustion engine to operate normally.

In such a situation, the "brains" are changed to a suitable analogue, after which the engine control unit is flashed. In this article, we will talk about how to replace an ECU with an engine with your own hands.

To begin with, in the event of a failure of the control unit, this device must be changed, since repairs are often impractical. Given the high cost of the device, it is often practiced to replace it with a used control unit, less often a new computer is purchased.

In this case, for replacement, special attention should be paid to the selection of the control module. The control unit must not only be suitable for the model, but also correspond to one or another type of engine. In other words, most often the ECU only fits from a similar car model with exactly the same internal combustion engine.

The electronic unit monitors the operation of the ignition system, fuel injection, evaluates the composition of the exhaust gases, etc. In each car model, an on-board computer is individual for a specific type of vehicle.

As mentioned above, the need to replace the engine control unit may arise for various reasons. In most cases, failures in the control unit do not allow normal operation of the car, as a result, the replacement of the ECU is required.

Taking into account the fact that the engine control unit is an electronic device, its high sensitivity to voltage drops in the on-board network and short circuits was noted. Also, moisture is not allowed to enter the ECU housing. Another unit may fail due to increased vibrations, shocks, etc.

By the way, among the most common reasons for the failure of the on-board computer is still a voltage drop, that is, a short circuit in the car's electrical circuits. We also add that in the case of obvious problems with the battery or generator, when the voltage is simply not enough, the ECU may also begin to malfunction.

Also, within the framework of diagnostics, it is very important to determine the very reason that led to the failure of the controller. Please note that if the cause is not found, then replacing the motor control unit may re-result in a breakdown of the newly installed device.

It is important to understand that engine malfunctions are often not associated with the ECU itself. Failure of ECM sensors, incorrect operation of actuators, breakdowns of the power unit itself and other reasons do not allow the unit to ensure stable operation of the power plant.

As for the unit itself, at the initial stage, the voltage on the ECU is checked. Then diagnostic equipment is connected to the unit, operability is tested, input and output signals are tested. Only the tests carried out in the complex allow us to conclude that the control unit is inoperative and needs to be replaced.

Now let's move on to the replacement itself. Please note that replacing an engine control unit can be difficult if the necessary skills are not available. As a rule, the ECU must be found first. In other words, you should know where the ECU is on the car, depending on the make and model of the vehicle.

The fact is that manufacturers do not always install ECUs in an easily accessible place. There are many reasons for this, ranging from protecting the control unit from vibration, moisture and temperature extremes, and ending with protection against theft.

In the second case, the main task is to make it difficult to access the device so that the hijacker does not have an easy opportunity to replace the block, bypass the immobilizer, etc. It is quite obvious that the ECU can stand both in the engine compartment and in the passenger compartment. To find the controller, you may need to partially disassemble the passenger compartment, remove attachments from the engine, etc.

After that, you need to check the operation of the ECU, and only then assemble the interior in the reverse order. If the attachment was removed from the engine, you first need to install all the parts and elements back, and only then check the performance of the new unit.

Also, during the test, it is advisable to connect the appropriate equipment to the diagnostic connector. This will ensure that the engine and other systems are operating normally with the new ECU.

By the way, on many cars the unit needs adaptation. In practice, especially when it comes to a car with a solid mileage, this means "self-tuning" of the controller, taking into account the wear of the internal combustion engine, reduced performance of the fuel pump, injectors, etc. It turns out that after replacing the ECU, the engine will not reach optimal performance immediately, but some time after the start of the car's operation.

Although the electronic components of many manufacturers are officially non-repairable, specialists often quite successfully restore these devices. This means that the possibility of repairing the ECU should not be completely ruled out either. If the unit is very expensive or rare, then the possibility of repairing the ECU may be a way out of this situation.In the case when all the work is done correctly, additional tuning of the ECU allows you to improve individual technical characteristics of the motor on a particular car. As a rule, the engine starts to “pull” better at low revs, dips disappear when the gas pedal is pressed sharply, the engine works more elastic in different modes, etc.However, one should not forget about the disadvantages of chip tuning. If a program of an unknown manufacturer is installed, the specialists did not “run in” the firmware on the fly, etc., then the engine resource may be noticeably reduced, there are problems with mixture formation, the revolutions may start to float, the engine “dulls”, the responsiveness to pressing the accelerator pedal disappears, under loads the internal combustion engine stalls, etc.For the reasons stated above, flashing the ECU should only be performed by qualified personnel using special equipment. It is important that the software (firmware) is proven and of high quality, after which mandatory adjustments are also made on the fly (the so-called online ECU firmware run-in).

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 shock 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 example of the model Bosch M 7.9.7... These are the “brains” that are installed on the latest car models. VAZ and many foreign cars.

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's 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. Image - DIY car ECU repair

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 ECU is an electronic control unit for the motor, in fact, it is one of the main units in the car, it is popularly called the brain. If something is wrong with the brains, then the car engine will not work normally, so it is necessary to repair the engine brains as soon as possible.Today we will talk about the reasons due to which the ECU fails, as well as how to diagnose the ECU on your own and what equipment is needed for this.Every modern car uses a huge amount of electronics, and as you know, electronics fail over time. But what is eternal in this world? But according to statistics, brains fail quite rarely. Image - DIY car ECU repair

The most common cases when brain repair is required are:

after a strong blow, the ECU may be damaged, that is, cracks may appear in the boards;
if the motor is overheated, then there are cases that the brains also fail from the temperature drop;
the appearance of rust if moisture gets into the housing of the motor control unit, which happens quite rarely;
and also, incorrect chip tuning may be the cause of ECU breakdowns;
brains can be damaged if you light another car while the engine is on;
also the cause of damage to the ECU may be an incorrect connection of the battery.

These reasons can not do much harm to the control unit, but can immediately disable the brain.

But on the other hand, it is possible to diagnose the brain, this will save the ECU from breakdown, of course, it all depends on the specific case. It is advisable to diagnose the ECU once a year or during each maintenance. Because repairing brains is a rather expensive procedure, and a new control unit costs a lot of money.

Brain diagnostics can even be handled by a non-professional, because all brains come with a self-diagnostics system that is already built into the control unit.

The engine control unit is a kind of computer that processes signals from sensors and interacts with other systems in the car.

The most popular brains used in many modern cars are the Bosch M 7.9.7. In order to diagnose the ECU, you need to connect to it using a laptop or a tester. The laptop must have a program. ,

For diagnostics, you can use the KWP-D program, which is free, you also need an adapter that supports the KWP2000 protocol. To make diagnostics - you need to connect the adapter - insert one end into the laptop, the other - the ECU port. Next, you need to turn on the ignition and turn on the program. Then a message will appear stating that the diagnostics have started and a table with important vehicle parameters should appear.

Errors that are issued from the motor are located in the DTC section. If errors are found, then you need to go to the "Codes" section, where you will see the decryption of errors. If there are no errors, then everything is in order with the motor.

You also need to look at other sections, there is data about the battery, throttle position, etc.

For those who are worried about increased fuel consumption, you need to monitor the QT parameter, it is he who speaks about fuel consumption. During idling, this section should contain the following figures: 0.6 - 0.9 l / h. You also need to check the LUMS_W section, which is responsible for the crankshaft during rotation, if it has a rate of more than 4 rpm, this means that the mixture is ignited unevenly in the cylinders. Therefore, it is necessary to check the voltage in the candles, as well as the candles themselves and high-voltage wires.

To diagnose brains, you need to buy an oscilloscope, which will show all the necessary information about all the nodes in the car.

The price of the oscilloscope is within 5,000 rubles, but you will also need a motor tester, which is designed to diagnose the motor, its cost does not exceed 3,000 rubles. With its help, you can determine why the speed drops and other problems with the motor occur.

And then a video on how to flash Bosch ECU 7.9.7:

Any car owner should know how to check an engine control unit. It contains too many all kinds of sensors, the main task of which is to optimize the operation of different nodes and their harmonious interaction with each other. If harmony is disturbed, at least you will lose in speed, agility, spare parts life, fuel consumption - and, ultimately, in money.As a maximum - at a certain stage, your car simply won't start.

How to check the engine control unit? Basically, not very difficult, even if you are not too friendly with an electrician. You just have to tighten up a little. In any case, if you suspect the ECU of incorrect operation, they will not just take it for repair at the service station - you will have to clearly outline your claims.

The easiest option is the conductor flew. If so, breathe a sigh of relief: by "ringing" the control unit and finding out which one, you can replace it (often yourself). In any case, the masters will not charge dearly for most of them. Much worse if the firmware is covered.

There were times when the owner, locked tightly in the car, was taken to the service station by a tow truck. You will not be able to reflash the microprocessor on your own - unless, of course, you are an expert in this area. So it is in your best interest to check the engine control unit: in the initial stages of a software failure, such disasters do not occur, and in the future they can be prevented in time.

The only thing you need is a multimeter and a wiring diagram for the unit. The first one will have to be bought (it is not included in the complete set of cars of far from all brands), and the latter is necessarily in the documents attached to the car. You will have to study the scheme carefully. If the ECU does not give out random data, but points to a certain block, find it on the diagram and start "ringing" it.

In the absence of accurate data, the entire system will have to be checked. Having found a breakdown, measure the resistance again and determine exactly where the wire is attached. Parallel to the old one, without removing it, solder a new one with the same parameters. If this is the problem, it should work. If it did not help, perhaps a block or some part of it flew. In this case, sighing heavily, stomp to the service station.

In order not to face such difficulties, it is worth taking care of the engine control unit in advance. Remember: electronics are a delicate thing, and it is this one that is subject to dust, temperature extremes, and moisture. If you value your four-wheeled horse, learn the block diagram as a multiplication table, and call it at the slightest malfunction. Does not show fuel consumption - you can live without these indicators (some manage to estimate it by mileage). However, the failure of this sensor may herald the coming more severe "jambs".

If you already know how to check the engine control unit, do not be lazy to apply your skills. Preventive measures can prevent big problems and significant costs.

Repair of the motor control unit

To diagnose the ECU with your own hands, you need to connect to the device, for this you 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.

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 fluctuations can also cause a car 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).

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To carry out diagnostics, you need to contact a specialized car service, in which, using a special module and cable, specialists connect to the control unit and make its diagnostics.The module is connected to a special computer on which a program is installed that recognizes error codes that are displayed on the screen when diagnosing the control unit. If necessary, specialists also use multimeters.

Thus, the specialist captures various indicators in real time. It can detect throttle position, fuel ratios, or temperature, for example. Carrying out diagnostics for a variety of models of modern cars is not difficult, in addition, the computer's firmware is constantly updated, which means that the computer receives new data on new types of control units. After the diagnostic procedure has identified errors, specialists begin to repair the engine control unit, replace or restore the factory settings, resetting the errors that appear.

Repairing an engine ECU is a rather complicated and time-consuming process and is recommended only in cases where replacement of the control unit is impossible for any reason, or when replacement may become too expensive for the car owner. It is not recommended to repair the ECU with your own hands at all, there is a great risk of damaging the electronic "brains" completely, which will disable all the accompanying systems of the car.

There are many reasons why the electronic control unit fails or any malfunctions in its operation begin. Among the most common breakdowns, one can distinguish such as lack of visibility behind the ABS sensor, lack of contact with the ignition unit, injector operation controller, as well as lack of contact with various sensors, throttle position or temperature sensor. In addition, the control unit may fail as a result of mechanical damage or moisture ingress on the microcircuit. Thus, in the event of a malfunction in the unit, overvoltage may occur, which sometimes completely disables the system. Overheating, moisture ingress, rust, moisture - all this can cause damage to the electronic unit. Also, experts from numerous car services note a high proportion of calls to them by motorists who tried to repair the control unit with their own hands or entrusted this business to unprepared people. Image - DIY car ECU repair

It is important to remember that an ECU consists of many complex connections, and therefore a poor-quality repair with your own hands can provoke serious problems in the operation of this unit. As for new car models, in case of problems with the control unit, a complete replacement of this element is recommended. If the car has a warranty, then it is worth contacting the dealership, where the ECU will be replaced with a new one, while there are some car models whose engine control unit repair is impossible even by professionals. In any case, you should first carry out high-quality diagnostics, then consult with a specialist, and only after that decide what exactly to do with the failed control unit.

For many, it is no secret that a P0601 error is money, in fact, like other errors signaling a malfunction of the engine control unit. On the other hand, it is even good when the PCM signals its illness, because it is much worse when there is no apparent reason for replacing the unit, but it starts signaling non-existent faults or imitating them (not on purpose, of course).

In this case, too, the insidious PCM put a pig on it, actively showing that it allegedly has a spark plug, and maybe the nozzle, or maybe even the compression is to blame, but not he. But no, the transistor burned out, as a result of which, during warming up, the control of one injector was periodically turned off!

We buy the necessary parts and change them!

The unit has been repaired and installed on a car.The advantages of repairing are obvious: there is no monthly waiting for a spare part that costs a lot of money, it is not always possible to find a used, especially for rare cars, and repairs are much cheaper than a used one. There are also disadvantages. Of course, this is not a factory soldering (although there have been no precedents for the quality of work so far), during inspection you can also miss something glitchy in the block that cannot be visually inspected and then there will still be some poorly diagnosed problems with the PCM, as well as we must not forget about the quality of Chinese parts, because they even manage to lie in the markings of radio components. So the risk always remains. On the other hand, it is good when there is an opportunity to offer different repair options!

PS And this is just a beautiful photo 🙂

Video (click to play).

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