DMVR is a mass air flow sensor, or as it is popularly called, a flow meter. It is designed to regulate the flow of air through the throttle body to create the fuel mixture. If this sensor fails, more or less air may enter the cylinders, which will affect fuel consumption. The cleanliness of the throttle also affects the flow rate.
The video shows the symptoms of a faulty mass air flow sensor on a VAZ. A non-working mass air flow sensor was specially installed:
What is a DMRV?
This device is very necessary in order to determine the volume of air that fills the combustion chambers when the engine is running. The sensor is usually installed after the air filter in the power system.
When driving, the automobile power unit is supplied with 1 volume of fuel, as well as 14 equal parts of air. This prepares the correct fuel-air mixture. This is the key to proper operation of the motor in the most optimal modes for it.
For any violation of this ratio, the car owner will observe either increased fuel consumption, or a decrease in the power of the power unit, or both. If you know the signs of a malfunction of the mass air flow sensor, it is easy to identify a breakdown of the device.
The mass air flow sensor 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 these data, the required amount of fuel will be calculated.
The more the driver presses the accelerator pedal, the more air enters the combustion chambers. The sensor records the amount and sends a special command to the ECU to increase the volume of injected fuel. If the car is to run or drive more smoothly, then a small amount of air will be needed.
This is why you need a mass air flow sensor. It measures the required volumes of air for engine operation with maximum accuracy.
Speed sensor
Signs of a faulty phase sensor VAZ-2112 16 valves
8- and 16-valve “tens” are also equipped with a speed sensor. Thanks to this device, the electronic engine control system receives information about how fast the vehicle is moving. The sensor itself is installed on the vehicle's gearbox. As practice has shown, on VAZ 2110 cars this controller is characterized by fairly high reliability and a long service life.
But domestic developers could not do everything perfectly, so this device is characterized by several malfunctions:
- If a component fails or does not work correctly, then when idling, the power unit may turn off on its own.
- A failed regulator can partially affect the speed characteristics of the vehicle. Of course, if the device breaks down completely, the driver will not be able to know how fast it is moving.
Two speed controllers
How does the MAF 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 under 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 in dirt. But modern sensors have a self-cleaning system. Dirt is one of the reasons why the device fails, but 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 that it is not suitable for repair. If the sensor fails, it is simply replaced with a new one.
Replacing the knock sensor
If it requires replacement, then it is necessary to purchase a new device and install it as soon as possible. All car enthusiasts are primarily interested in the price of a new device. It is low and depends on the make of the car and on the country in which the part was manufactured.
You can carry out the replacement yourself when the engine has cooled down by disconnecting the negative terminal of the battery. It is necessary to achieve the most convenient access to the sensor so that it can be removed. The fact is that it also depends on the car model.
Thus, the knock sensor is a simple device, yet very useful for an electronic control system. It is not difficult to determine its malfunction; you can check it yourself, even in rural areas.
It will also be inexpensive to replace the sensor.
It doesn’t matter whether this is done by a specialist or independently
>
The second way is using a multimeter
Before performing these diagnostics, it should be noted that this will only work with a Bosch mass air flow sensor. Before performing the test, set the limit on your multimeter to 2 V, and then switch the device to constant voltage operation.
Turn on the ignition and connect the red wire to the yellow one on the block. Connect the black wire to the green one. At this moment the engine should not be running. Measure the voltage If the reading is between 1.01 and 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 it is higher, then you can again look for the cause of the breakdown.
Checking the regulator for functionality
There are several options for diagnosing the device.
To check the mass air flow sensor using a tester (multimeter), you will need to perform the following steps:
- First, you need to disconnect the plug from the device’s power supply, after which the multimeter probes are connected to the device. The red terminal must be connected to the yellow contact, and the black terminal to the green, that is, to ground.
- After performing these actions, the mass air flow sensor will operate in emergency mode, and the air flow dosage will be carried out according to the latest parameters. During diagnostics, the multimeter should display voltage parameters.
- Operation of the device is allowed if the voltage parameters are from 1.01 to 1.03 volts. If the values obtained are 1.04 volts or higher, then this indicates that the device is already wearing out or has completely failed. With such parameters, the device should be replaced as quickly as possible.
There is another verification option - alternative. To do this, simply disconnect 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.
External signs of a malfunction of the VAZ 2110 mass air flow sensor
This is the third way to diagnose the sensor. To determine its serviceability, carefully inspect the internal cavities of the air pipe where the mass air flow sensor is mounted. In order to do this, you will need a shaped 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 mass air flow sensor are dirt on the working surface. It is formed due to the fact that the air filter was not replaced in time. Oil deposits will tell the driver that the oil level in the lubrication system is high or that the oil cutter is not working properly. With these signs, the sensor may still work, but will soon fail.
Next you need to completely remove the mass air flow sensor. 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 imminent failure.
Source
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 carry out testing in the most basic ways.
March 23, 2022 105,361
The MAF (mass air flow sensor) is designed to estimate the amount of air entering the engine of a fuel injected vehicle. Based on its data, the electronic control unit (ECU) adjusts the composition of the fuel-air mixture. Let's look at the features of checking the mass air flow sensor with a multimeter.
DMRV of VAZ 2112 series
Traditionally for the AvtoVAZ family, the 2112 series was equipped with a whole set of engines with various options for ECU controllers. It is the version of this unit that determines which mass air flow sensor is installed on a particular VAZ 2112.
There are compatibility tables for electronic engine control units and flow meter models.
Mass air flow sensors are produced by various manufacturers: BOSCH, Siemens, Itelma, Avtel, etc. There is no fundamental difference between the brands, although drivers intuitively gravitate towards German products. Regardless of the logo on the device, the compatibility index is the same. Knowing the factory classification of the engine and the version of the ECU controller, you can always select a replacement mass air flow sensor.
For example, your VAZ 2112 is equipped with a 16 valve engine 21124 with a power of 90 l/s, with an environmental standard of Euro 3. The ECU controller on such an engine is BOSCH M7 9.7. According to the table, it corresponds to a flow meter with the index 0 280 218 116, the popular name is “one hundred and sixteenth”.
Information: some car enthusiasts claim that this index means compatibility only with 1.6 liter engines. This is an incorrect statement: the factory MAF classifier has no relation to the volume of the internal combustion engine.
Spare part selection
There are sensors on the market in three price categories:
- Inexpensive. Typically these are Chinese-made sensors priced up to 1,200 rubles.
- Average. This category includes sensors from AvtoVAZ and foreign analogues of approximately the same quality. Their price ranges from 1400 to 2600 rudders.
- Expensive. High-quality and reliable mass air flow sensors from manufacturers Bosch or Siemens. Their price can reach 5,000 rubles.
We recommend giving preference to original sensors from AvtoVAZ or foreign analogues in this price category.
Mass air flow sensor device (English abbreviation - MAF)
- The housing is made in the form of a cylinder, the diameter of which coincides with the air duct of the intake manifold. Installed at the outlet of the air filter (using the example of a VAZ 2112). The housing itself is a calibrated measuring channel.
- To protect against foreign objects, a deflector and a metal screen in the form of a mesh are installed at the entrance. The correct air flow is formed through them.
- The air flows through the flow sensor itself, which operates on the thermal anemometric principle. There are two resistors installed inside (reference and variable), connected to a common circuit using a ballast circuit. Variable, precision, changes resistance when cooling and heating. The thread of this resistor is made of an alloy of iridium and platinum. The control board monitors that the resistance is the same. To do this, a platinum thread cooled by an air flow is heated by electric current. The resistor is constantly supplied with voltage, the value of which varies with an accuracy of 1/1000 volt.
- The value of this voltage is output by the MAF circuit to pin No. 5 of the connector. The signal is read by the ECU controller and programmatically converts this value into air mass (kg/hour).
Types of mass air flow sensors
Mass air flow sensors are constantly being improved; today there are several meters that calculate consumed air:
- The main component is a pitot tube. The plate fixed in the sensor changes position under the influence of air flow. The inclination angle of the plate is measured by a potentiometer, which in turn changes the resistance. This serves as a signal for the control unit to determine the volume of incoming air.
- The mass production of modern mass air flow sensor devices requires the presence of hot-wire measuring mechanisms in the sensors. The heat exchanger contains 2 thin plates made of platinum. After energy is supplied to the plates to warm them up, one of them remains working, and the second - control. The MAF sensor in this design makes it possible to ensure a constant, identical temperature touching the 2 plates.
- The working elements of the film meter are silicon wafers coated with platinum.
Flow meter failure: signs and causes of failure
Of course, the absence of a sensor or incorrect readings will not lead to a complete stop of the car. Moreover, the mass air flow sensor is checked, among other things, by the on-board computer. However, the symptoms will not allow you to move normally on the road:
- loss of engine power, up to the inability to drive uphill;
- engine jerking when moving evenly;
- hanging at high speeds after releasing the gas (this can be dangerous);
- increase in fuel consumption up to two times;
- engine vibrations reminiscent of “triple movement”, leading to increased wear of mechanisms.
With the exception of natural wear (any mechanism has a service life), other causes of malfunctions are associated with contamination of the MAF sensors or moisture and oil entering it. These problems arise due to an irresponsible attitude towards car maintenance.
- untimely replacement of the air filter;
- installation of low-quality or “zero” filters;
- water getting into the air duct channel (driving through puddles at high speed, careless car washing);
- penetration of oil vapors into the flow meter housing due to a malfunction of the crankcase ventilation system;
- debris and foreign objects that have entered the measuring channel after repair work or car maintenance.
Advice: do not rush to change a clogged flow meter; you can try to clean it with compressed air or a special aerosol for mass air flow sensors or carburetors.
Let's summarize
From the above, we can conclude that you can check the VAZ 2110 mass air flow sensor using a multimeter yourself. By comparing the ADC readings with computer diagnostics, we can say that the test with a multimeter is correct.
It is also worth noting that if you want to maximize the life of the air flow sensor, change the air filter more often. The manufacturer recommends replacement every 30 thousand kilometers. We recommend reducing this interval to 20 thousand kilometers, and if you mainly travel on dusty roads to 15 thousand km. mileage
The process of replacing the MAF VAZ 2110, 2111, 2112 is clearly shown in this video:
Source
How to check the mass air flow sensor with a multimeter
Self-diagnosis will not only allow you to avoid sudden problems, but will also indicate the timing of a possible replacement of the flow meter. The object of measurement is contact No. 5 on the connector. The quiescent voltage is measured relative to the negative contact No. 3.
We turn off the engine, turn the ignition key to the “ON” position, but do not turn the starter. We connect the measuring leads to the mass flow sensor connector.
- good condition: voltage within 0.98 V - 1.02 V;
- there is wear, but it is not critical: 1.03 V - 1.04 V;
- critical wear, replacement soon: 1.05 V;
- voltage more than 1.05 V – sensor is faulty.
Signs of malfunction of the DMVR
Mass air flow sensor design
Signs of a malfunctioning mass air flow sensor can be direct or indirect . Let's consider all possible options:
- Check Engine light on the dashboard. In most cases, the CHECK indicator lights up due to the failure of one of the sensors, so you need to connect to the ECU to accurately determine the fault.
- A drop in power 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 fuel pressure sensor must also be checked. About standard fuel consumption indicators here.
- Reduced acceleration dynamics . An incorrect amount of air mixture that enters the combustion chambers produces a poor ignition mixture, which in turn does not allow the car to accelerate normally and leads to jerking when the gas pedal is sharply pressed.
- Poor start-up or inability to start . A rich or lean fuel mixture cannot detonate normally, which will lead to just such problems. It is also possible that fuel will not burn through and there will be popping noises in the muffler.
- Floating idle speed. Different amounts of air entering the fuel mixture will have 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 using a multimeter
The mass air flow sensor is quite easy to check. For diagnostics you will need a multimeter.
- We disconnect the chips from the sensor power supply and insert the probes of the measuring device.
We connect the probes of the measuring device: red to yellow, and black to green (to sensor ground).
Voltage readings of a working and faulty sensor
- 1.01-1.02 — readings from 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 you have the money, then we’ll change it. Fuel consumption may be reduced.
- 1.05 and higher - the mass air flow sensor is not working.
Measurement using paper clips - there may be an error on the device. According to the readings, it is clear that the sensor “ordered to live long”
Alternative verification method
The second way to check the performance of the mass air flow sensor is to disconnect the power from it and drive a few kilometers. If engine performance has improved, then the problem is in the mass air flow sensor.
Where to look for the VIN number?
Since there are no strict requirements for placing the VIN code on a car, it can be located in different places in different brands and models of cars (the manufacturer usually indicates these places in the documents for the car). Most often, the code is indicated under the hood near the windshield, and can also be located:
- at the junction of the dashboard and windshield on the driver's side;
- on the bottom of the pillar, behind the driver's seat (the marking is visible when the door is open);
- on the chassis;
- on the side members.
