A modern car is literally stuffed with electronics. It is problematic for an ordinary motorist to understand the numerous cunning devices, and there is no need, because control of complex and finely tuned systems is taken over by control units.
Control units - brains vehiclethat control the operation of the engine, gearbox (gearbox), power supply, exhaust gas recirculation system, air suspension, and other components. As a result, in case of failures in one of the control units, almost all systems of the car will not work correctly.
Autotech center VWService offers services for the diagnosis and repair of control units for cars of the VAG group (Volkswagen, Audi, Skoda and Seat), Toyota, Lexus, LandRover, Ford.
ECU diagnostics
Diagnostics is testing to identify faults. It is produced with the help of special electronic equipment equipped with original software. It is even difficult for a non-specialist to imagine how much electronics is involved in diagnosing control units. Mostly, special scanners are used.
The diagnostic devices of the VWService car service center perform the following functions:
- identify and identify the control unit
- read fault codes from all available vehicle systems
- control the state of executive devices and mechanisms
- monitor changes in the operation of these devices
- reset service indicators, set the interval until the next vehicle maintenance.
In the process of diagnostics, all data about the tested vehicle are compared with the database stored in the device memory. Based on the identified differences with the standard, the optimal technology and sequence of work to eliminate all faults are automatically generated. The repair itself consists in replacing the failed circuits, the effectiveness of the repair is checked by repeated testing.
ECU repair
VWS car repair specialists provide repair services for control units:
- engine
- air suspension,
- immobilizer and other auto electronics;
- block adaptation, i.e. interface of peripheral electronic sensors and devices with a control unit after a violation of the settings that occurred during the repair or replacement of peripherals. The common service for synchronizing the engine control unit and the immobilizer is also a special case of adaptation.
Considering that the "vital activity" of a vehicle directly depends on the correct operation of all its constituent systems, there is nothing surprising in the existence of a certain "think tank" that monitors their condition and activity. This center is the electronic control unit (ECU). Malfunctions of this structural part of the car are immediately displayed on the operation of the power supply of the transmission, exhaust system and other "controlled" elements. Now we will try to understand the principle of operation of the electronic control unit, and also consider the main causes of its breakdowns and ways to eliminate them.
1. The principle of operation and features of the electronic control unit
In the field of automotive electronics, this device is a general term that unites any embedded systems, which, in turn, control one or more mechanisms in the subsystems of the car. The types of electronic control units are divided into: electronic engine control unit (most common type), central control unit, combined engine transmission control unit, control unit braking system, central control module, main electronic module, suspension control module, body controller, central synchronization module, etc.
Sometimes, all these systems, taken together, are called the car computer, although with technical point view is several blocks. Quite often, one assembly can include a large number of separate control modules. So, individual modern cars combine up to 80 electronic control units, and their built-in software continues its successful development. In this regard, the management of an increased number of complex vehicle ECUs plays a major role in its efficient operation today.
The main type of electronic control units for a car is the engine ECU (it is also often referred to simply as an electronic unit). The use of this device qualitatively optimizes a number of basic vehicle parameters: power, fuel consumption, maintenance level harmful substances in exhaust gases, etc. It is presented in the form of a certain computing device, the main task of which is expressed in processing information coming from input sensors and transmitting corresponding control commands based on it to various systems engine.
From the constructive point of view, such a block consists of a box (hardware) and the software necessary for the operation, the central part of which is the processor. This is where data from all sensors comes in power unit, after which they lend themselves to processing and subsequent analysis. In addition to the traditional sensor information (such as position and RPM or air flow), additional data have been added about vehicle speed, oxygen level in the exhaust gases, irregularities road surface, a request to turn on the air conditioner and a bunch of other signals aimed at optimizing the engine's workflow. The number of sensors of modern cars has long exceeded 20.
Installation of software is required to carry out computational operations. A distinctive feature of modern electronic control units is the possibility of reprogramming, which made it possible to move away from the serious restrictions set by the factory program and open up new horizons for the application of engine tuning, for example, installing a turbocharger or equipment for using alternative fuels.
We will not now go into the essence of the activities of each individual ECU, since it will take a very long time, but rather we will focus our attention on the described electronic engine control unit, because, as we have already noted, it is he who is the key to the effective functioning of the power unit, and therefore the whole car.
2. Reasons for ECU failure
Any electronic control unit is an important piece of equipment, and the appearance of malfunctions in it can cause the entire mechanism to malfunction. Being a kind of "brain center" of the entire ECU system, it is responsible for all processes occurring in it, therefore even minor damage to the microprocessor can cause malfunctions in the transmission, emission control system, charging system and many other components of the vehicle's viability. The main signs of failure of the electronic control unit are considered to be refusal to start the engine, constant messages about violations of its operation, which are not cleared in any way, and some other symptoms.
In principle, the appearance of malfunctions in the operation of an ECU is a rather rare phenomenon that, usually, cannot be predicted, and in order to identify and confirm a breakdown, manufacturers and repair companies have to perform the following checks:
- checking the electronics and the possibility of overheating;
Checking parts for corrosion and destruction;
Assessment of the assembly quality of the block itself, conduct fractography.
Fulfillment of all the above conditions at the test stage will prevent damage in the future and significantly increase productivity.
Today, there are a lot of reasons for the failure of this device, and they all depend on the type of electronic unit, its location and key functions. Among the most common of them, they distinguish the lack of contact with the ignition unit, various sensors, an operation controller, a temperature sensor, as well as the impossibility of monitoring the operation aBS sensor... In addition, the breakdown of the device is seriously affected by mechanical damage from vibration and shock or moisture ingress on the microcircuit (seeping inside, water often causes short circuit and corrosion).
Thus, in the event of any malfunction, overvoltage may occur in the electronic unit, which often completely disables the system. Also, the specialists of many car services, environment possible reasons ECU breakdowns highlight a significant proportion of those that were formed as a result of attempts by motorists to repair the device on their own, or they entrusted this matter to dubious professionals.
Special attention, I would like to pay attention to the causes of breakdowns that occur in the electronic engine control unit. These include:
- "lighting" from a car with a running engine;
Inconsistency of polarities when connecting the battery;
Lack of necessary knowledge and skills when installing alarms and conducting renovation works on the part of electrics;
Removing the battery terminal while the engine is running;
Inclusion of the starter with a disconnected power bus;
Ingress of moisture into the electronic control unit;
Short circuit or complete break in the wiring;
Contact with the electrode from welding on the wiring or sensors of the vehicle;
Malfunctions in the high-voltage part of the ignition system: coils, wires, distributor, etc.
However, no matter what type of control unit we are talking about, the main thing to remember is that it consists of many rather complex connections, which means that attempts to independently carry out repair work can provoke serious problems in the operation of this unit. As for representatives of new vehicle models, when a malfunction occurs in the control unit, it is recommended complete replacement the specified device. If the car is still on warranty service, then it would be reasonable to contact the dealer center, where the unit will be replaced.
Note! Repair of electronic engine control units of some car models is generally impossible, even if you seek help from the most qualified professionals. However, be that as it may, the initial stage of solving the problem, first of all, is high-quality diagnostics, and then, after consulting with specialists, it is possible to decide the further fate of the failed computer.
3. Repair of the electronic control unit
Repairing an electronic control unit is a rather complicated and time-consuming procedure, which is recommended to be used in extremely rare cases: when it is impossible to replace it, for whatever reason, or when it is too expensive for the car owner. Experts do not advise starting independent repair actions at all, since there is a high probability of damage to the electronic "brains", which, in turn, will disable all accompanying vehicle systems.
Given the complexity of the ECU device, it cannot be repaired in a conventional station. maintenance, where, after making sure that there is a problem, it will simply be replaced with a new one. For a more significant check of the unit's operability, it is necessary to carry out special testing using special equipment that is available only in specialized service centers. Before replacing a failed mechanism, you should find out and eliminate the cause of its "death" and although this task may be quite difficult, it will save you from the possibility of a quick re-replacement.
The bulk of the commercially available control units were once in use, and after failure, they were simply restored at the manufacturing plant, which, by the way, is much more profitable than creating a part from scratch. Of course, not all broken mechanisms are subject to a restoration procedure. So, for example, an ECU from a “drowned man” that has been covered with water for a long time, most likely no one will repair it.
Despite the fact that in terms of external parameters (shape, size, the same arrangement of contacts), electronic control units may look exactly the same, their settings will still differ significantly. This is not surprising, because they are all responsible for the operation of car engines. different brandsreleased at different times. If you install the wrong ECU model, the vehicle may even drive, but none of its systems will work stably. That is, it is necessary that the replaceable electronic unit fully corresponds to the broken one. Therefore, when buying an ECU, you need to know the brand of the vehicle, the year of its manufacture, the engine size and the code indicated by the manufacturer on the block.
Each electronic control unit has a microcircuit "PROM"where all system settings are saved this car... Most often, when replacing an ECU, it is simply rearranged from the old unit to a new one, and in more modern models vehicles, instead of a microcircuit, flash memory is used or EEROM - a rewritable storage device.
When installing the unit, the main task is to connect the device to the wiring of the machine, using the appropriate connectors for this. The difficulty in this case, mainly lies in the inconvenience of the location of the ECU, which makes it difficult to get to it. However, before attempting any wiring, it is important to remember to disconnect the battery terminal.
Many electronic control units, after connecting the wires, taking into account the parameters of the vehicle, require additional adjustment. In each case, this process is individual and should be described in the vehicle's service manual. Only specialists from authorized service centers can perform the reprogramming procedure, also called "chip tuning".
Before contacting them for help (taking the computer for repair or tuning), you should have some data about your car. First of all, based on the registration certificate or technical passport of the vehicle, determine its brand, model, year of manufacture, name (letters in front of the number), engine size, type of transmission ( mechanical box or automatic). Next, remove the device and write down the manufacturer's name and catalog numbers from its label. All this information will need to be reported to the service center employees who will deal with the elimination of the problem.
A modern car is a complex assembly consisting of a set of components, including many electronics. For the normal functioning of the car, the coordinated work of the components according to the specified algorithms is required. Provides synchronous and correct work electronic control unit (ECU) - a unit with which many components of the car are equipped.
General definition
An electronic control unit means any system based on a microprocessor that is responsible for the operation of one or another electrical component of the car (or several subsystems). Often in English literature, the term ECU is found, which stands for Electronic Control Unit.
There are types of blocks:
- simply ECU - managing any ECU subsystem, except for the engine;
- ECM - the module responsible for the engine (in English Engine Control Module);
- combined engine-transmission ECU, which controls both the gearbox and the engine;
- brake control system;
- automatic transmission control unit;
- Suspension control ECU;
- central control ECU and synchronization unit;
- main ECU;
- etc.
Total controllers in a modern advanced vehicle equipped with the latest engineering technology, sometimes up to 80, and more. Together, the ECUs make up a single system - the car computer.
An important element of the ECU is its software ("firmware"). She is responsible for the logic of the components, and the modification of the ECU firmware can significantly change performance characteristics cars. This is often used by tuning enthusiasts and racers who programmatically enhance certain aspects of their "iron horse" - optimizing fuel consumption, acceleration parameters, and much more.
Engine control module
It can be called one of the main ones, since this electronic unit is responsible for the heart of the machine - its motor. The ECU receives information from a variety of sensors, analyzes it based on algorithms embedded in the firmware, and sends appropriate signals to various actuators.
Engine ECU exchanged with other elements internal system vehicle via a bus called CAN (CANbus), which connects all the electronic stuffing of the vehicle into a network. The main blocks with which the motor ECU "communicates":
- Automatic transmission;
- anti-lock braking (ABS) system;
- stabilizing systems;
- brakes;
- security block;
- exchange rate stability module;
- cruise control;
- climatic installation.
The main tasks of the engine ECU:
- ignition process control;
- if, then control of the injection system;
- control over the gas distribution of the motor;
- throttle sensor tracking;
- maintaining the target temperature in the cooling system;
- analysis of the composition of exhaust gases and control of the recirculation subsystem thereof.
The ECU sensors receive data from the crankshaft sensors, reporting its speed and current position. The unit reads the speed of the car, the parameters of the voltage in the on-board power supply, and a lot of other information. The ECU has a built-in self-diagnosis system that lights the CheckEngine signal on dashboard in case of malfunction. In parallel with this, the error code of the detected error is recorded in the ECU memory, which can later be read through the service connector using special device and software. This helps identify the problem.
On modern cars Commonly used OBD2 diagnostic universal connector:
Any device that works on this protocol and is able to "read" data from memory is connected to it.
Engine ECU device
Technically, this electronic unit consists of a board with a processor and a memory module soldered on it. The ECU board is enclosed in a metal or plastic housing. On the board there are connectors brought out through the body that connect the ECU with the systems of the car and allow connecting diagnostic devices. The instructions for the car always indicate the location of the ECU: usually this is the place behind the glove compartment, the engine compartment, or inside the front dashboard.
The ECU on board has three types of storage devices (memory):
- EPROM - Programmable Read Only Memory. It contains the firmware code and the parameters by which the power plant operates;
- RAM - operational memory, otherwise "RAM" of the ECU. It is volatile, it stores temporary information;
- ERPZU. The electrically programmable memory stores some data - lock codes, access keys, information about fuel consumption, mileage and engine operation period.
The ECU firmware is divided into a control part and a functional part. The first checks the signals coming to the unit and, if incorrect values \u200b\u200bare found, corrects them or blocks the engine, preventing damage. The second receives data, processes it and sends the result from the ECU in the form of pulses to the desired devices.
The scheme of the engine ECU:
Functions and tasks of the ECU box
The ECU is responsible for performing several tasks:
- control of box modes and switching them if necessary;
- system diagnostics;
- memorizing errors for further analysis of the problem and repair.
The ECU is usually mounted in its own case:
ECU location
Control block automatic transmission can be located:
- directly in the automatic transmission case;
- outside of that.
The first option allows you to significantly reduce the amount of wiring in the car, since fewer wiring "harnesses" go from the electronic brain of the ECU to the sensors. But there are also disadvantages:
- heavy temperature regime... The box heats up significantly during operation, which negatively affects the thin electronic filling of the ECU controller board;
- difficulties in repair: any operation with an ECU requires disassembling the box, which makes repairs more difficult and expensive.
Example of ECU location inside the box:
The external location of the ECU is devoid of the drawbacks of the internal one: not such high temperatures, you can additionally protect the ECU from moisture and other negative influences. In addition, access to the unit for service and repair operations is facilitated, and engineers have the opportunity to position the ECU in a convenient way.
But there is also a disadvantage: with this arrangement, the ECU has to stretch long harnesses to tie together the ECU, sensors and servos.
ECU malfunctions
Most common reason breakdown of the automatic transmission control module:
- a strong blow to the box (the ECU board, processor or memory chip cracks);
- vibration effects;
- heat;
- voltage surges in the on-board network;
- corrosion by moisture.
A faulty electronics box leads to incorrect gear shifting or a situation where the automatic transmission goes into emergency modeworking in only one gear (usually in third). If there is any suspicion about the health of the box ECU, you should contact a specialized service as soon as possible.
Important: moving on a faulty automatic transmission is strongly discouraged! This can lead to damage not only to the ECU, but also to the mechanical part of the box. The car should be taken to the service on a tow truck.
Diagnostics of a faulty box ECU is carried out with special equipment. Usually, they try to simply replace a faulty ECU, because if it is still relatively easy to re-solder the burnt out capacitors, replacing the ECU microcircuits is a laborious operation, while a suitable chip still needs to be found. Therefore, often the best way - replacement of the ECU, such a step will completely solve the problems with the box and return it to working capacity.
Another important point - only a knowledgeable specialist should repair the ECU of the box (and any in principle). Automatic transmission repair services are offered by many "garage" services, but they are not able to guarantee the quality of the service, and after their intervention, the box is able to "die" completely.
Other types of ECU
The rest of the control blocks that control others electronic systems (cruise control, brake control module, lighting, etc.) operate on similar principles and are subject to similar malfunctions.
It is important to monitor the state of the car electronics and ECUs, service them and promptly apply for repairs in case of malfunctions: this will ensure the smooth and well-coordinated operation of all car systems.
In modern cars, all electrical equipment is combined into a single system called an electrical package. The management of the power package is assigned to special electronic units - read everything about these devices, their design and functionality, as well as the right choice and replacement in the article.
What is an electrical control unit?
(electrical accessories controller, comfort unit, central body electronics unit) - a component of the vehicle electrical system; electronic device based on microprocessors / microcontrollers, serving as a central control unit for auxiliary systems and electronic components of the vehicle in order to increase its comfort and safety.
In modern cars and many trucks various electrical equipment - power windows, exterior and interior lighting and light signaling, door locks, drive of rear-view mirrors and more - assembled into a single system, which is called power accessories (EP). The functions of control and management of the electronic signal are assigned to the central control unit (controller). The use of the power package control unit allows you to implement various control schemes for automotive electrical equipment:
- Manual control using the appropriate switches on the dashboard, doors, steering column switch, etc .;
- Remote control of electrical equipment using car alarms or telematic systems;
- Automatic control of some elements in accordance with the state of the car, engine controller and on-board computer;
- Automatic control of the main elements that ensure the safety of the car (central locking, windows, lights) when the status of the car alarm and / or immobilizer changes.
Thus, the power package control unit allows you to increase the comfort and safety of the car, as well as expand the functionality of its electrical system by using the advantages and capabilities of the CAN, LIN, K-Line and others data transfer protocols.
A malfunction of the EA controller can completely disrupt the functioning of the vehicle's electrical equipment, so this unit must be replaced as soon as possible. To make the right purchase of a new unit, you need to understand the existing types of these devices, their features and functionality.
The design of electrical control units
All modern EP controllers are built on the basis of microprocessors or microcontrollers, which take over the functions of controlling electrical equipment circuits. The processors have algorithms for controlling equipment in various situations - when manual control, in automatic mode etc. Direct control of the equipment is carried out by means of small-sized electromagnetic relays or electronic keys based on powerful field-effect transistors.
The electronic components are located on a printed circuit board, which is installed in a plastic case, the connection to the electrical equipment is made using standard electrical connectors. One to three connectors can be installed on one unit, often the power and control circuits are separated, separate connectors are used to connect to them.
Located under the dashboard or center console, it is usually installed near mounting block relays and fuses - this reduces the length of the cables between these nodes. The unit is mounted with screws or with a metal bracket.
Types and functionality of electrical control units
The electrical control units used in various vehicles may differ in functionality and operating characteristics, but in general they are responsible for controlling the following electrical equipment:
- Window regulators of all doors and window regulator locking mechanism;
- External (side) rear-view mirrors drive;
- Heated exterior mirrors;
- Heated rear window;
- Heated front seats;
- Central locking;
- Locking mechanism and locks of the trunk and hood;
- Front and rear direction indicators;
- Interior lighting - ceiling lamp, B-pillar lamps, threshold lamps, luggage compartment lighting;
- Instrument panel illumination;
- Outdoor lighting devices - fog lights and rear fog lights, parking lights, reversing light.
Enabling, disabling and changing the operating modes of the specified electrical equipment is carried out by supplying control signals to the executive devices - electric motors or gear motors, heating elements or lamps / LEDs. Closing of circuits, as already mentioned above, is carried out by appropriate relays or keys. Control signals are generated by several microcontrollers and control driver microcircuits, the number of which in the control unit can reach five or more. Each microcontroller and driver is responsible for different devices, usually separate microcircuits are used to control power windows, outdoor and indoor lighting, central locking, etc.
Moreover, not every power package controller has all the specified functionality. As a standard, this unit is responsible for controlling the window lifters, mirrors and the central lock, with extended functionality, the unit controls interior and exterior lighting and other electrical appliances. Accordingly, vehicles with different configurations use electronic control units that are not the same in functionality and capabilities.
It should be noted that in our country, the electrical equipment control system, which, in addition to windows, locks and mirrors, includes other equipment, is often called a full power package (PEP). However, this is more a marketing ploy than a reflection. real opportunities systems - many foreign cars have more possibilities than the so-called PEP in domestic cars.
How to choose and replace the electrical control unit
Despite the high reliability, the EC control units can fail, which entails a malfunction of the vehicle's electrical equipment. A malfunction of this unit is indicated by both failures of single devices (for example, the inability to turn on or incorrect operation of direction indicators, power windows, etc.), and the failure of several devices at once (for example, all external and internal lighting, glass and seat heaters, etc.) etc.). In any case, the fuses of the corresponding equipment are checked first, and only then the diagnostics of the electrical control unit is carried out.
In some cases, the EP control unit is subject to repair, which boils down to replacing a failed microcontroller or other parts. However, sometimes it is easier and cheaper to replace an assembled unit than to hand it over for repair (especially if the car has a minimum EDS configuration without an immobilizer control function). In this case, a replacement unit of the same type and model (as well as catalog number) must be used as a replacement. In some cases, the installation of a block of a different model is possible, but most often this is hampered by the need to change the pinout of the connectors or requires abandoning some functions.
The unit must be replaced in accordance with the instructions for the repair and maintenance of the vehicle. Usually the work comes down to dismantling the old unit and installing a new one, but first of all, you need to get access to this deviceand this may require partial disassembly of the dashboard or console. Since electrical installation is carried out using standard connectors, no soldering or other operations are required, and the new control unit starts working immediately after installation and power supply to the car's electrical system.
If the controller of the power package works together with an alarm and / or an immobilizer, then before starting work, they must be turned off (transfer to service mode or complete shutdown). Otherwise, there may be problems with the operation of electrical equipment or just trouble with abnormal operation of the security system.
The correct choice and replacement of the electrical control unit is the basis reliable work electrical equipment of the vehicle.
Control units for window drives are vital for the correct organization of all automatic ventilation and smoke extraction systems using window openings. It is thanks to these devices that the possibility of building and organizing complex automatic systems with one centralized control. Thanks to them, the following tasks can be accomplished within the framework of the "smart home" project:
- timely closing of all windows and transoms in the house at the beginning of rain, strong winds or other significant changes in the environment;
- simultaneous opening of a row of windows to ventilate an individual floor or a row of rooms without significantly cooling the rest of the house;
- closing all windows at the request of the owner of the house and pressing just one button;
- programming of various modes with different levels of room ventilation;
- timely response of the system to the appearance of smoke in the room (the smoke exhaust control unit is activated);
- connection of many different external sensors and implementation of the logic for responding to certain events.
Why is it worth purchasing control units from us?
This kind of electronics is an essential part of any automated system. That is why it is very important to purchase original devices with a quality certificate from the manufacturer. Our store is the official representative of the Aprimatic company in Moscow. This means that here you can find original control units for the ventilation system, smoke removal, etc., fully compatible with the automated control systems for doors and windows of this manufacturer.
