MAF is a mass air flow sensor. It is located in the engine power system, in the intake tract, and is considered the most important among the main instruments and components in the injection system of any power unit. Like any other vehicle component and any part, the DMRV can fail. Let's look at the main symptoms of a DMRV malfunction, and also find out the principle of operation and functionality of this equipment.
What is DMRV?
This device is very necessary in order to determine the volume of air that will fill the combustion chambers when the engine is running. The sensor is usually installed after the air filter in the power system.
When driving, an automobile power unit is supplied with 1 volume of fuel, as well as 14 equal parts of air. This is how the correct fuel-air mixture is prepared. This is the key to the correct operation of the motor in the most optimal modes for it. With any violation of this ratio, the owner of the car will observe either increased fuel consumption, or a decrease in the power of the power unit, or both at once. If you know the signs of a malfunction of the DMRV, then it is easy to identify a breakdown of the device.
DMRV is necessary in order to accurately measure the required amount of air. This amount is calculated in the sensor itself, and then sent to the ECU, where, based on this data, the required amount of fuel will be calculated.
The more the driver presses the accelerator pedal, the more air will enter the combustion chambers. The sensor detects the amount and sends a special command to the ECU to increase the volume of injected fuel. If the car will run or move more evenly, then a small amount of air will be needed. That's what the DMRV is for. It measures the required volume of air for the operation of the motor with maximum accuracy.
Measuring the volume of air means determining the load that will be applied to the motor. When the accelerator pedal is pressed, the throttle valve opens and the amount of air received increases.
How does the DMRV work?
This device is a small wire made of platinum alloy. The size of this cord is only 70 microns. It is installed in a special tube, which is located in front of the throttle valve.
This wire is cooled by the air flow. To regulate the temperature between it and the air flow, electricity is applied to the wire. The charge level can be adjusted. The more the wire is blown, the more electricity is supplied.
Due to constant use, this wire is constantly covered with dirt. But modern sensors have a self-cleaning system. Dirt is one of the reasons why the device fails, however, there are other signs of a malfunction of the MAF sensor. Although the design of the device is as simple and reliable as possible, it also fails. Its only drawback is its unsuitability for repair. If the sensor fails, it is simply replaced with a new one.
DMRV VAZ - signs of malfunction and diagnostics
If this sensor fails, the "Check Engine" light will most likely be on on the dashboard.
Also, the motor will definitely lose power and dynamic characteristics in its characteristics. Also among the main signs are increased appetites of the motor and difficult starting of the internal combustion engine.
Methods for diagnosing DMRV
There are several options for checking the MAF. Signs of a problem show up almost immediately. Let's look at them together.
The first way is to turn off the sensor
This verification method is the easiest. It can be done by every car owner. The first step is to disable the sensor. To do this, you just need to unplug the connector. Then you should start the engine. As a result, the ECU controller will go into emergency mode. And the supply of the fuel mixture will be regulated only with the help of a throttle valve. Idling will be around 1500 rpm. After that, you need to make a check-in by car. If the car has added in the dynamic characteristics of acceleration, then it makes sense to look for signs of a malfunction of the DMRV.
The second way is with a multimeter
Before performing these diagnostic measures, it should be noted that this will only work with the Bosch MAF. Before testing, set your multimeter to the 2V limit, and then set the machine to constant voltage operation.
Turn on the ignition, and connect the red wire to the yellow on the block. Connect the black wire to the green. At this point, the engine should not be running. Measure voltage
If the readings are from 1.01 to 1.02, then everything is fine. The multimeter shows voltage up to 1.03 - there is nothing to worry about, this is acceptable. The limit level is 1.05. If higher, then you can again look for the cause of the breakdown.
External signs of a malfunction of the DMRV VAZ 2110
This is the third way to diagnose the sensor. To determine its serviceability, carefully inspect the internal cavities of the air pipe where the DMRV is mounted. In order to do this, you will need a curly screwdriver. Loosen the clamp and disconnect the corrugated pipe. The surface of the corrugation should be as dry as possible, without an oil film.
It should be noted that the main signs of a malfunction of the DMRV are dirt on the working surface. It is formed due to the fact that the air filter was not replaced on time. An oil coating will tell the driver about a high oil level in the lubrication system or about the incorrect operation of the oil separator. With these signs, the sensor may still work, but will soon fail.
Next, you need to completely remove the MAF. You will find signs of a malfunction after a visual inspection of the device. To carry out this operation, you will need a 10 key. Unscrew the two screws and remove the device from the air filter housing. A rubber seal will come out with the sensor. If the seal remains in the housing, this is the main sign of an imminent breakdown.
Main symptoms
So. If you have problems with the MAF, the symptoms of a malfunction can be very different. Among them, one can single out failures during acceleration, lack of traction, and a decrease in power. There is a persistent feeling that the car simply "does not go." If there is no proper reaction when you press the gas, then this is one of the signs. High fuel consumption is also a signal for diagnosing this sensor. When your car stops when shifting from gear to gear, it makes sense to check the MAF sensor. VAZ 2110 has the same symptoms as other cars.
If you have difficulty starting a cold engine, if the engine is unstable, if the speed spontaneously increases or, conversely, decreases, if detonations occur under load - these are all signals for checking and diagnosing the sensor.
Sensor cleaning
If you observe signs of a malfunction of the DMRV, then you can try to clean the device.
By the way, this is the most expensive sensor of all in the line of front-wheel drive VAZ cars. But if you have it out of order, do not rush to change it. There is a small chance of restoring his "health". For the cleaning process, you will need a special liquid that is used to clean the carburetor. An asterisk wrench will also come in handy. Unscrew the clamp, as well as two bolts on "10". Remove the pipe and take out the sensor. Spray the wire and tube with liquid. Work with extreme care, wait until this liquid has completely evaporated and leave the device to dry.
While the instrument dries, remove the throttle assembly. You will see plaque inside the throttle assembly. It must be removed with liquid. This dirt is the cause of the malfunction of the entire system. Because of it, problems with the DMRV appear, signs of a malfunction of the VAZ 2115, which bother beginners on automotive forums.
Do not remove the throttle cable. Place the knot on a rag and treat especially dirty areas with liquid. Don't forget to flush the idle air control and the area underneath.
After that, most likely all signs of problems with the DMRV will go away, of course, provided that the sensor has no mechanical damage. Therefore, do not wait until you have the first signs of such problems, but do such prevention this coming weekend. It will not take you much time, and your car will breathe for real. You won't recognize your engine. It will start much better, its traction will improve, you will notice an increase in the power of your engine.
Carry out such preventive maintenance regularly, and your car will thank you.
Modern VAZ 2112 cars are equipped with various devices and sensors that ensure optimal engine operation. If one of the main components fails, this will negatively affect the functionality of the machine as a whole. For more information about what 2112 is, where it is located and how to clean it if necessary, read this article.
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Characteristics and features of the DMRV on the VAZ of the twelfth model
DMRV or mass air flow sensor is a device whose purpose is to assess the volume of air flow entering the motor of the machine. This controller is one of the main devices of the electronic control system of the power unit. Failure of the DMRV will lead to unstable engine operation.
As for the location, this device is located behind the air filter element housing. To find the device, open the hood of the car and find the air filter housing, right behind it is the DMRV. The operation of a car with a faulty controller may be difficult or impossible (the author of the video is Sergey Marunchenko).
Possible sensor malfunctions
There may be several device malfunctions:
- the sensor is clogged with dirt;
- mechanical damage to the device;
- lack of contact, that is, damage to the power supply wiring of the device.
The main symptoms of controller failure:
- The check indicator appeared on the control panel. As practice shows, this lamp most often lights up when the controller breaks down, so to determine the malfunction, you need to connect to the electronic control unit.
- Reduced engine power. Of course, this symptom is indirect, since a decrease in power may be due to various malfunctions, but, nevertheless, it cannot be ignored.
- Increased fuel consumption. Such a problem can also be attributed to the failure of the fuel pump or fuel filter, however, the performance of the DMRV must also be checked.
- In addition, the acceleration dynamics of the car will be reduced. As a result of less air entering the combustion chambers, the quality of the air-fuel mixture as a whole will be lower. Accordingly, because of this, the car cannot accelerate normally. And if you step on the gas, then when accelerating, the VAZ 2112 can move jerkily.
- Poor starting of the engine, in more severe cases, the engine will not start at all. This, again, is due to a poor-quality combustible mixture. Such a mixture can cause detonation, which contributes to poor engine starting. In addition, uncharacteristic pops can be heard from the exhaust pipe.
- When the car is idling, the engine speed will float. This problem is due to the different volume of air flow that enters the combustible mixture (the author of the video is Sandro's channel in the garage).
Checking the regulator for performance
There are several options for diagnosing the device.
To use a tester (multimeter), you will need to perform the following steps:
- First, the plug must be disconnected from the power supply of the device, after which the multimeter probes are connected to the device. The red output must be connected to the yellow contact, and the black output to the green, that is, to ground.
- After performing these steps, the DMRV will operate in emergency mode, and the air flow will be dosed according to the latest parameters. When diagnosing, the multimeter should display voltage parameters on the display.
- The operation of the device is allowed if the voltage parameters are from 1.01 to 1.03 volts. If the obtained indicators are 1.04 volts and higher, then this indicates that the device is already wearing out or completely out of order. With such parameters, the device should be replaced as soon as possible.
There is another option for checking - alternative. To do this, simply unplug the power plug from the controller, start the car engine - you need to drive. If you notice that when the controller is turned off, the operation of the power unit has become more efficient, then the cause of the malfunction lies precisely in the sensor.
Troubleshooting methods
You do not have many options for solving the problem - you can either try to clean the sensor or replace it with a new one.
The cleaning and replacement procedure is described below:
- First you need to dismantle the DMRV. To do this, loosen the bolt that secures the corrugated hose to the device body, then disconnect it.
- Next, you need to unscrew two more screws, with which the DMRV is fixed to the air filter housing. Having done this, you can dismantle the controller. If you decide to change it, then you will just need to install a new DMRV, and reassemble in the reverse order. But if you want to try to restore its performance, you can clean the device.
- After dismantling the regulator, it must be disassembled. There are coils on the device, so when dismantling the regulator, be careful not to damage them. As practice shows, these spirals are very sensitive, there are even cases when car owners, simply by wiping the DMRV with a rag, put it out of action.
- Now you will need a special tool for cleaning carburetors, which can be purchased at any store. Before cleaning, make sure that the pressure from the cylinder is not strong, as excessive pressure can also damage the device. The body of the device itself should not be heavily processed, since the plates and spirals are most contaminated, so these components need to be processed as much as possible.
It should be noted that this process should be carried out in several stages. The bottom line is to allow the device to dry a little after processing - this will allow the dirt to sour as much as possible. The procedure must be repeated several times with a short interval, eventually the DMRV will need to be washed. The cleaning process itself is repeated until transparent, clean drops of cleaner begin to flow from the sensor. Then you can mount the device in place by assembling all the components in reverse order.
Photo gallery "Cleaning the DMRV"
Video "Visual instruction for cleaning the DMRV"
A more visual instruction for cleaning the controller is given in the video below (the author of the video is the IZO))) LENTA channel).
For optimal operation of an injection internal combustion engine (hereinafter referred to as ICE), one should take into account how much air mixture enters the combustion chambers of the cylinders. Based on these data, the electronic control unit (hereinafter referred to as the ECU) determines the conditions for supplying fuel. In addition to information from the mass air flow sensor, its pressure and temperature are taken into account. Since DMRVs are the most significant, we will consider their types, design features, diagnostic and replacement options.
Appointment and decoding of the abbreviation
Flow meters, they are also volume meters or DMRV (not to be confused with DMRT and DVRM), stand for mass air flow sensors, installed in cars with diesel or gasoline ICEs. It is not difficult to find the location of this sensor, since it controls the air supply, then you should look for it in the corresponding system, namely, after the air filter, on the way to the throttle valve (DZ).
The device is connected to the engine control unit. In cases where the DMRV is out of order or absent, a rough calculation can be made based on the position of the remote sensing. But with this method of measurement, high accuracy cannot be ensured, which will immediately lead to excessive fuel consumption. This once again indicates the key role of the flowmeter in calculating the fuel mass supplied through the nozzles.
In addition to information from the DMRV, the control unit also processes data from the following devices: DRV (camshaft sensor), DD (knock meter), DZ, cooling system temperature sensor, acidity meter (lambda probe), etc.
Types of DMRV, their design features and principle of operation
Three types of volume meters are most widely used:
- Wire or thread.
- Film.
- Volumetric.
In the first two, the principle of operation is based on obtaining information about the mass of the air flow by measuring its temperature. In the latter, two accounting options can be involved:
Swirl sensor design (widely used by Mitsubishi Motors manufacturer) Designations:
- A - pressure measurement sensor, for fixing the passage of the vortex. That is, the frequency of pressure and the formation of vortices will be the same, which makes it possible to measure the flow rate of the air mixture. At the output, using the ADC, the analog signal is converted to digital, and transmitted to the computer.
- B - special tubes that form an air flow close in properties to laminar.
- C - bypass ducts.
- D is a column with sharp edges on which Karman vortices are formed.
- E - holes used to measure pressure.
- F is the direction of the air flow.
Wire gauges
Until recently, the filament DMRV was the most common type of sensor installed on domestic cars of the GAZ and VAZ model range. An example construction of a wire-wound flowmeter is shown below.
Designations:
- A - Electronic board.
- B - Connector for connecting the DMRV to the ECU.
- C - CO adjustment.
- D - Flow meter housing.
- E - Ring.
- F - Platinum wire.
- G - Resistor for thermal compensation.
- H - Holder for the ring.
- I - The casing of the electronic board.
The principle of operation and an example of a functional diagram of a filament volumemeter.
Having dealt with the design of the device, let's move on to the principle of its operation, it is based on the hot-wire method, in which a thermistor (RT), heated by a current passing through it, is placed in an air stream. Under its influence, the heat transfer changes, and, accordingly, the resistance RT, which makes it possible to calculate the volumetric flow rate of the air mixture? using the King equation:
I 2 *R=(K 1 +K 2 * ⎷ Q )*(T 1 -T 2) ,
where I is the current passing through RT and heating it to a temperature T 1. In this case, T 2 is the ambient temperature, and K 1 and K 2 are constant coefficients.
Based on the above formula, you can derive the volume flow rate of the air flow:
Q \u003d (1 / K 2) * (I 2 * R T / (T 1 - T 2) - K 1)
An example of a functional diagram with a bridge connection of thermoelements is shown below.
Designations:
- Q is the measured air flow.
- U - signal amplifier.
- R T - wire thermal resistance, usually made of platinum or tungsten filament, the thickness of which is in the range of 5.0-20.0 microns.
- R R – temperature compensator.
- R 1 -R 3 - ordinary resistance.
When the flow rate is close to zero, the RT is heated to a certain temperature by the current passing through it, which allows the bridge to be held in equilibrium. As soon as the flow of the air mixture increases, the thermistor begins to cool, which leads to a change in its internal resistance, and, as a result, an imbalance in the bridge circuit. As a result of this process, a current is formed at the output of the amplifying unit, which partially passes through the thermal compensator, which leads to the release of heat and allows you to compensate for its loss from the air mixture flow and restore the balance of the bridge.
The described process allows you to calculate the flow rate of the air mixture, operating on the magnitude of the current passing through the bridge. In order for the signal to be perceived by the ECU, it is converted to a digital or analog format. The first allows you to determine the flow rate by the frequency of the output voltage, the second - by its level.
This implementation has a significant drawback - a high temperature error, so many manufacturers add a thermistor similar to the main one to the design, but do not expose it to air flow.
During operation, dust or dirt deposits can accumulate on the wire thermistor, in order to prevent this, this element is subjected to short-term high-temperature heating. It is performed after the engine is turned off.
Film air meters
A film DMRV works on the same principle as a filament one. The main differences are in the design. In particular, a silicon crystal is used instead of a platinum filament wire resistance. It is covered with several layers of platinum sputtering, each of which plays a certain functional role, namely:
- temperature sensor.
- Thermal resistance (usually two of them).
- Heating (compensation) resistor.
This crystal is installed in a protective casing and placed in a special channel through which the air mixture passes. The channel geometry is designed in such a way that temperature measurements are taken not only from the input stream, but also from the reflected one. Due to the created conditions, a high speed of the air mixture is achieved, which does not contribute to the deposition of dust or dirt on the protective case of the crystal.
Designations:
- A - The body of the flow meter, into which the measuring device (E) is inserted.
- B - Contacts of the connector that connects to the computer.
- C - Sensitive element (silicon crystal with several layers of sputtering, placed in a protective casing).
- D - Electronic controller, with the help of which the preliminary processing of signals is performed.
- E - The body of the measuring device.
- F - Channel configured to take thermal readings from the reflected and input stream.
- G - Measured air mixture flow.
As mentioned above, the principle of operation of filament and film sensors is similar. That is, the sensing element is initially heated to a temperature. The flow of the air mixture cools the thermoelement, which makes it possible to calculate the mass of the air mixture passing through the sensor.
As with filament devices, the output signal can be analog or converted to digital by an ADC.
It should be noted that the error of filament volumemeters is about 1%; for film analogues, this parameter is about 4%. However, most manufacturers have switched to film sensors. This is explained both by the lower cost of the latter and by the extended functionality of the ECUs that process information from these devices. These factors overshadowed the accuracy of instruments and their speed.
It should be noted that thanks to the development of technology for manufacturing flash microcontrollers, as well as the introduction of new solutions, it was possible to significantly reduce the error and increase the speed of film structures.
Interchangeability
This issue is quite relevant, especially considering the cost of original products of the imported auto industry. But everything is not so simple here, let's give an example. In the first production models of the Gorky Automobile Plant, a DMRV Bosch (Bosh) was installed on injection Volga. Somewhat later, imported sensors and controllers replaced domestic products.
A - imported filament DMRV manufactured by Bosh (pbt-gf30) and its domestic counterparts B - JSCB "Impulse" and C - APZ Structurally, these products practically did not differ with the exception of several design features, namely:
- The diameter of the wire used in the wirewound thermistor. Bosch products have a diameter of 0.07 mm, while domestic products have a diameter of 0.10 mm.
- The method of attaching the wire, it differs in the type of welding. For imported sensors, this is resistance welding, for domestic products - laser welding.
- The shape of a filament thermistor. At Bosh, it has a U-shaped geometry, APZ produces devices with a V-shaped thread, the products of AOKB Impulse are distinguished by a square shape of the thread suspension.
All the sensors given as an example were interchangeable until the Gorky Automobile Plant switched to film counterparts. The reasons for the transition have been described above.
Film DMRV Siemens (Siemens) for GAZ 31105 It makes no sense to bring a domestic analogue of the sensor shown in the figure, since outwardly it practically does not differ.
It should be noted that when switching from filament devices to film devices, most likely, it will be necessary to change the entire system, namely: the sensor itself, the connecting wire from it to the computer, and, in fact, the controller itself. In some cases, the control can be adapted (reflashed) to work with another sensor. This problem stems from the fact that most filament meters send analog signals, while film meters send digital signals.
It should be noted that the first production VAZ cars with an injection engine were equipped with a filament DMRV (manufactured by GM) with a digital output, as an example, models 2107, 2109, 2110, etc. can be cited. Now they are installed DMRV BOSCH 0 280 218 004 .
To select analogues, you can use information from official sources, or thematic forums. For example, below is a table of interchangeability of DMRV for VAZ cars.
The presented table clearly shows that, for example, the DMRV sensor 0-280-218-116 is compatible with VAZ 21124 and 21214 engines, but does not fit 2114, 2112 (including 16 valves). Accordingly, you can find information on other VAZ models (for example, Lada Granta, Kalina, Priora, 21099, 2115, Chevrolet Niva, etc.).
As a rule, there will be no problems with other brands of cars of domestic or joint production (UAZ Patriot ZMZ 409, DEU Lanos or Nexia), choosing a replacement for the DMRV will not be a problem for them, the same applies to products from the Chinese automobile industry (KIA Ceed, Spectra, Sportage etc.). But in this case, it is likely that the DMRV pinout may not match, a soldering iron will help correct the situation.
The situation is much more complicated with European, American and Japanese cars. Therefore, if you have a Toyota, Volkswagen Passat, Subaru, Mercedes, Ford Focus, Nissan Premiere R12, Renault Megan or other European, American or Japanese car, before replacing the DMRV, you must carefully weigh all the solutions.
If you are interested, you can search the net for an epic attempt to replace the “native” air meter with an analogue on the Nissan Almera H16. One attempt resulted in excessive fuel consumption even at idle.
In some cases, the search for an analogue will be justified, especially if we take into account the cost of a "native" volumetric meter (BMW E160 or Nissan X-Trail T30 can be cited as an example).
Health check
Before diagnosing the DMRV, you need to know the symptoms that allow you to determine the degree of performance of the MAF (an abbreviation for the English name of the device) of the sensor in the car. We list the main symptoms of a malfunction:
- The consumption of the fuel mixture has increased significantly, at the same time, acceleration has slowed down.
- ICE at idle runs with jerks. In this case, in idle mode, a decrease or increase in speed can be observed.
- The engine does not start. Actually, this reason in itself does not mean that the flow meter in the car is faulty, there may be other reasons.
- An engine problem message is displayed (Check Engine)
An example of the displayed message "Check Engine" (marked in green) These signs indicate a possible malfunction of the DMRV, in order to accurately determine the cause of the breakdown, it is necessary to perform diagnostics. It's easy to do it yourself. Connecting a diagnostic adapter to the computer (if this option is possible) will help to greatly simplify the task, after which, by the error code, determine the health or malfunction of the sensor. For example, error p0100 indicates a malfunction in the flow meter circuit.
But if it is necessary to carry out diagnostics on domestic cars manufactured 10 years ago or more, then the DMRV can be checked in one of the following ways:
- Testing while driving.
- Diagnostics using a multimeter or tester.
- External inspection of the sensor.
- Installation of the same type, known to be working device.
Let's consider each of these methods.
Testing while driving
The easiest way to check is by analyzing the behavior of the internal combustion engine with the MAF sensor turned off. The algorithm of actions is as follows:
- It is necessary to open the hood, turn off the flow meter, close the hood.
- We start the car, while the internal combustion engine goes into emergency mode. Accordingly, a message about a problem with the engine will be displayed on the dashboard (see Fig. 10). The amount of fuel mixture supplied will depend on the position of the remote control.
- Check the dynamics of the car and compare it with what it was before the sensor was turned off. If the car has become more dynamic, and power has also increased, then this most likely indicates that the mass air flow sensor is faulty.
Note that you can drive further with the device turned off, but this is highly discouraged. Firstly, the consumption of the fuel mixture increases, and secondly, the lack of control over the oxygen regulator leads to an increase in pollution.
Diagnostics using a multimeter or tester
Signs of a DMRV malfunction can be established by connecting the black probe to ground, and the red probe to the sensor signal input (you can see the pinout in the passport for the device, the main parameters are also indicated there).
Next, we set the measurement limits in the limit of 2.0 V, turn on the ignition and take measurements. If the device does not display anything, it is necessary to check the correct connection of the probes to the ground and the signal of the flow meter. According to the readings of the device, one can judge the general condition of the device:
- A voltage of 0.99-1.01 V indicates that the sensor is new and is working properly.
- 1.01-1.02 V is a used device, but its condition is good.
- 1.02-1.03 V - indicates that the device is still operational.
- 1.03 -1.04 the state is approaching critical, that is, in the near future it is necessary to replace the DMRV with a new sensor.
- 1.04-1.05 - the device resources are almost exhausted.
- Over 1.05 - a new DMRV is definitely needed.
That is, it is possible to correctly judge the state of the sensor by voltage, a low signal level indicates a healthy state.
Visual inspection of the sensor
This diagnostic method is no less effective than the previous ones. All that is needed is to remove the sensor and evaluate its condition.
Inspection of the sensor for damage and presence of liquid Typical signs of a malfunction are mechanical damage and liquid in the device. The latter indicates that the oil supply system to the engine has not been adjusted. If the sensor is heavily soiled, the air filter should be replaced or cleaned.
Installing a similar, known-good device
This method almost always gives a clear answer to the question of sensor performance. In practice, this method is quite difficult to implement without purchasing a new device.
Briefly about the repair
As a rule, MAF sensors that have become unusable cannot be repaired, except in cases where they require flushing and cleaning.
In some cases, it is possible to repair the volumetric mass air flow sensor board, but this process will briefly extend the life of the device. As for boards in film sensors, without special equipment (for example, a programmer for a microcontroller), as well as skills and experience, it is pointless to try to restore them.
Today I decided to share with you one useful information, maybe it will be interesting to someone, and it will really come in handy in case of a real malfunction on the car. An air flow meter is installed on the VAZ 2112 16 valves, the role of which is to measure the amount of air that enters the engine. Indeed, the stable operation of the power unit depends on the correct ratio of the mixture (gasoline + air), which burns in the cylinders. And in general, fuel consumption. You can check the health of this unit yourself at home, without stopping by the service station.
How to check
Method number 1: Disable the DMRV.
Disconnect the sensor connector and start the engine. If you turn off the DMVR, then the controller switches to emergency operation and prepares the fuel mixture only according to the throttle position. The engine speed must be over 1500rpm.
Let's try to ride. If it feels like the car has become “faster”, then we can say that the DMRV is not working.
By the way, for ECU Ya7.2, M7.9.7. turns when turning off the chips do not rise!
Method number 2: Alternative ECU firmware.
If the standard firmware of the controller was replaced with another, then it is not known what is sewn in it in case of emergency mode in method No. 1. Try putting a 1mm thick plate under the damper stop. The turnover will go up. Pull the chip from the DMRV. If it doesn’t stall, then the matter is in the firmware, or rather with the IAC steps in emergency mode without the DMRV.
Method number 3: Checking the DMRV with a multimeter.
This method works on Bosch sensors with catalog numbers: 0 280 218 004, 0 280 218 037, 0 280 218 116.
We turn on the tester in the DC voltage measurement mode, set the measurement limit to 2 Volts.
The video shows the symptoms of a faulty DMRV sensor on a VAZ. A non-working DMRV was specially installed:
Symptoms of a malfunction of the DMVR
Mass air flow sensor device
Signs of a malfunctioning mass air flow sensor can be direct or indirect. Consider all possible options:
- . In most cases, the CHECK indicator lights up due to the failure of one of the sensors, so you need to connect to in order to accurately determine the malfunction.
- Power drop is only an indirect sign, since there may be another reason for this malfunction.
- Increased fuel consumption . Of course, everything can be attributed to the fuel pump, but the DMVR must also be checked. .
- Decreased acceleration dynamics . The wrong amount of air mixture that enters the combustion chambers gives a bad incendiary mixture, which in turn does not and results.
- Bad start or its impossibility . Rich or can not detonate normally, which will entail just such problems. And it is also possible that the fuel does not burn out and.
- . A different amount of air entering the fuel mixture will give an effect when the speed will either decrease or increase.
To accurately determine the malfunction of the DMVR sensor, it is necessary to diagnose it.
How to check the MAF sensor?
The mass air flow sensor is checked with a multimeter
The mass air flow sensor is fairly easy to check. For diagnostics, you need a multimeter.
Voltage readings of a good and a faulty sensor
- 1.01-1.02 - the readings of the new sensor, everything is normal.
- 1.02-1.03 - there is wear, but the parameters are within normal limits.
- 1.03-1.04 - the parameters are working, but there is already wear.
- 1.04-1.05 - critical parameters, get ready for replacement, if there is money, then we change. Fuel consumption may be reduced.
- 1.05 and up- non-working MAF sensor.
Measurement with paper clips - there may be an error in the device. According to the testimony, it can be seen that the sensor "ordered to live long"
Alternative way to check
The second way to check the performance of the mass air flow sensor is to turn off the power from it and drive a few kilometers. If the engine performance has improved, then the problem is in the DMRV.
conclusions
It is quite easy to determine the malfunction of the mass air flow sensor VAZ-2112 16 valves. To do this, you need to know the direct and indirect reasons that contribute to the diagnosis, as well as to check in the most elementary ways.
