Many car owners are inclined to believe that if the “Check Engine” light is not on, then everything is in order and there cannot be any breakdowns. But this is not true at all.
The “check” light comes on only when the control unit detects a malfunction of one of the sensors. But, for example injectors or candles, module ignition, regulator idle move- they are not sensors. And if they break down, the injector fault lamp will not light up.
But from proper operation The operation of the injection engine depends on these mechanisms. Moreover, the breakdowns are not obvious. That is, the sensor works but gives incorrect readings that differ from real ones. We will talk about such malfunctions with you.
It is not always possible to detect them on your own, but we will try. Reasons for failure involving injector sensors:
Crankshaft sensor
The only sensor that, if it fails, will not even start the car is crankshaft sensor The malfunction is rare but does happen sometimes.
Also, when the distance between the sensor and the drive disk increases, engine malfunctions begin.
An indirect sign of the need to check the CPCV (Crankshaft Position Sensor) may be the absence of ignition. Because it is the pulses from the DPKV that are used by the control unit to calculate the timing of the spark and fuel injection.
This means that there may be no spark not only due to malfunctions in the ignition system, but also due to a failure of the crankshaft position sensor.
Camshaft position sensor
If it malfunctions or breaks down, the injectors switch to an asynchronous mixture supply mode. This means that the mixture is injected into each cylinder, regardless of what stroke the piston is in.
In such cases, fuel consumption increases and the Check Engine light usually comes on. Moreover, the consumption on viburnum when this sensor breaks down increases to 18 liters per hundred kilometers!
Coolant temperature sensor
The check engine light can only light up if there is a break or short circuit. If the sensor lies too much and shows the wrong temperature, then the car may not start at all. The reason is simple.
Imagine that the true engine temperature is +20 degrees, and the sensor shows -20. What happens in this case? The control unit gives a command to inject more fuel (!), as a result, the cylinders are overfilled with fuel assemblies (fuel) and the engine “chokes.”
Oxygen sensor
If it breaks down, it is also possible, especially on old Japanese cars. Sometimes the sensor continues to work, but again gives incorrect data, as a result, the flow rate deteriorates and general dynamics cars. Interruptions in engine operation may occur.
In most cases, an error code is entered into the control unit’s memory and a lamp lights up indicating a malfunction of the “Check Engine” injector.
Mass air flow sensor
DMRV.
The car may operate intermittently, sometimes even stalling while driving or when changing gears. The engine does not start well.
If, as usual, it starts when you press the gas pedal, then the reason may be the mass air flow sensor.
It shows the control unit how much air is entering the engine. And the unit, based on these readings, calculates how much fuel to inject.
Throttle position sensor
TPDZ. If your car reacts inadequately to pressing the accelerator pedal or floats and changes spontaneously, then this sensor may be the culprit. Also, the engine may not start if the TPS gives incorrect data.
Imagine that you start the engine without pressing the gas pedal, as you should. And the sensor shows that the pedal is pressed halfway. What's happening. Of course, the control unit increases the amount of fuel injected, believing that you have pressed the pedal and “you need to give it gas.”
As a result, the cylinders are again flooded with an excess of mixture, the car stalls or does not start at all. The “Check” lamp may not light up, because the sensor is working, it’s just lying.
Injector malfunctions involving actuators:
Idle speed control
RXX. But this is no longer a sensor, but an actuator. Its task is to provide the engine with air at idle. The moment you release the gas pedal, the IAC opens the air bypass channel. If the sensor is dirty, it may open air access late or not at all.
As a result, the engine stalls due to the over-richness of the mixture. Moreover, people sometimes associate this malfunction with the brake pedal.
That is, they say this: “the car stalls when you press the brake pedal.” In fact, it stalls when you release the gas, because when you brake, you usually release the gas. 🙂
An injection engine is quite complex mechanism, which must be well-tuned to get maximum performance from it. The article discusses in detail the operating principle of an injection engine.
The content of the article:
Before we start talking about this miracle of technology, let's dispel some myths. An injection engine works on the same principle as a diesel engine, with the exception of the ignition system, however, this does not give it much more more power than carburetor. The increase will be a maximum of 10%.
The center of the entire system is the ECU (electronic control unit). It goes by many names, "brains", "computer" and so on. Essentially, yes, it’s a computer that contains a huge number of tables on mixture composition, fuel injection time, and so on. For example, if the engine speed is 1500, the throttle is open 10 degrees, and the air flow is 23 kg, then one amount of fuel will enter the cylinder. If the input parameters change, then the result will be different. If any problems arise with the control unit, for example, the firmware crashes, then everything goes to waste, the engine either starts to work haphazardly or stops altogether.
Injection engine sensors
All elements can be divided into actuators and sensors. First, we'll look at sensors.
Mass air flow sensor (MAF)
This element is installed before air filter, right at the entrance. Its operation is based on the principle of difference in readings. So, electricity passes through two platinum filaments. Their resistance changes depending on the temperature. One of the threads is reliably hidden from the air flow, which makes its resistance unchanged. The second one is cooled by the flow, and based on the difference in values, according to the same tables mentioned above, the ECU calculates the amount of air.
Engine absolute pressure and temperature sensor (DBP)
It is used either as an alternative or in conjunction with the above for higher reading accuracy. In short, it has two chambers, one of which is sealed and has an absolute vacuum inside. The second chamber is connected to the intake manifold, where a vacuum is created during the intake stroke. Between these cameras there is a diaphragm, as well as piezoelectric elements. They generate tension when the diaphragm moves. The signal then goes to the ECU.
Crankshaft position sensor (CPS)
If you look at the crankshaft pulley of an injection engine, you can see a comb on it. It's magnetic. There are teeth along the entire perimeter. There should be 60 of them in total, every 6 degrees. But two of them are missing; they are needed for synchronization. The crankshaft position sensor has a magnetized steel core and a copper winding. When teeth pass through the winding, an induction current arises, the voltage of which depends on the speed of rotation of the pulley.
Phase sensor (PF)
Not all engines were equipped with it before, but now it can be found almost everywhere. It works on the principle of a Hall sensor, that is, it has a disk with a coil, as well as a slot. As soon as the slot hits the sensor, the output voltage on it is zero. This moment means the top dead center of the compression stroke of the first cylinder. This is necessary so that the ECU can generate voltage for ignition in the desired cylinder, as well as control the clock cycles. So that, for example, the nozzle does not open during the working stroke.
Knock sensor
It is installed on the cylinder block of an injection engine. As soon as detonation occurs in the engine, vibration is transmitted through the block. The sensor is a piezoelectric element that generates voltage; the stronger the vibration, the higher the voltage. Accordingly, the ECU adjusts the ignition timing based on its readings. But more on that later.
Throttle Position Sensor (TPS)
In essence, this is an ordinary potentiometer. The reference voltage on it is usually 5 volts. So, depending on the angle at which the throttle valve is deflected, the voltage at the control terminal changes. It's simple.
Coolant temperature sensor (DTOZH)
This sensor is needed to determine the engine temperature. If on a carburetor engine it is simply needed to turn the electric fan on and off, here it is a more complex device. This is thermal resistance, the value of which varies depending on temperature. Accordingly, the voltage also changes when passing through it.
Oxygen sensor
It is installed in the exhaust system; there are systems with two sensors. Its task is to monitor the amount of free oxygen in the exhaust gases. For example, if there is too much of it, it means that the whole mixture does not burn, which means it needs to be enriched. If there is less oxygen than what is indicated in the ECU standard tables, then it must be depleted.
Actuators
The actuators got their name because they make adjustments to the operation of the engine. That is, the control unit receives a signal from the sensor, analyzes it, and then sends the signal to the actuator.
Fuel pump
Let's start with the power system. It is installed in the tank and supplies fuel to the fuel rail at a pressure of 3.2 - 3.5 MPa. This ensures high-quality fuel spray into the cylinders. As soon as the engine speed increases, the appetite also increases, which means more fuel must be supplied to the ramp to maintain pressure. The pump begins to rotate faster at the command of the control unit. Most modern cars, starting around 2013, are equipped with a fuel module, which includes a pump and a built-in filter. This significantly affects the cost of filter replacement, because the entire module must be replaced. Some manufacturers write in the instructions that the module is installed for the entire service life of the car, but you should not believe that any filter can last more than 2 seasons.
Nozzle
After the fuel has passed the entire circuit of the wire, it enters the nozzle, which meters its supply into the cylinder. The nozzle is solenoid valve very small diameter, which ensures atomization of gasoline into the combustion chamber. The ECU modifies the amount of fuel supplied by time intervals while the injector is open. As a rule, this is tenths of a second.
Throttle valve
We have all once seen a carburetor and looked into it from above. So it had dampers that blocked the air. The principle is the same here. Perhaps there is nothing more to tell.
Idle air control (IAC)
This is also an electromagnetic valve, the rod of which closes the air duct that bypasses the throttle valve. Depending on the voltage that the control unit supplies to it, it opens this very channel.
Ignition module
In principle, this is the same ignition coil, only there are four of them. When current passes through the primary winding, a high-frequency current is switched into the secondary winding high voltage, which is fed to the candle.
The principle of operation of an injection engine
So, after we have figured out the main components of an injection engine, let's see how it works. After the starter cranks the crankshaft, the DPKV tells the control unit which cylinder is in which position. In turn, the phase sensor reported the clock cycles. The control unit took this information into account and opened the injector in the cylinder in which the intake stroke begins. But he opened it for a reason, but for a strictly defined period of time, which, according to the tables, corresponds to the readings of the mass air flow sensor or DBP. This is how the working mixture was formed.
Video: how a gasoline injection internal combustion engine works
After the intake stroke has ended here, compression begins, at which time intake occurs in the other cylinder. Here the piston reaches top dead center, as indicated by the DPKV and DF, respectively, it is time to apply voltage to the ignition module, to the desired cylinder. To do this, the control unit contains two transistors, which take over two cylinders each.
Then, when the explosion occurs, the ECU looks at the readings of the knock sensor and adjusts the ignition timing for the next cylinder along the stroke. But that is not all. After this, when the gases reach the oxygen sensor, the control unit adjusts the composition of the mixture, namely, the opening time of the injector, which allows for the most efficient use of fuel and its combustion. If the ECU detects a lack of oxygen, but the throttle valve remains open, the idle air control valve opens slightly.
Engine warm-up and engine temperature sensor
This point is worth considering separately; let’s just say this is a small clarification. So, the engine warm-up mode is in no way connected with the readings of some sensors, that is, nothing depends on them. In particular, these are mass air flow sensor and air pressure sensor, as well as a knock sensor. The block, as already mentioned, contains certain tables, there are a lot of them, millions. So, during the warm-up mode, the ECU works strictly according to these tables and nothing else. This means that if the air to fuel ratio is written into it as 14.1:1, then it will be so. This figure is the generally accepted standard for operating temperature. So, until the engine temperature reaches the one specified in the firmware of the control unit, the warm-up mode will not turn off. Afterwards the ECU starts working based on the sensors.
Which is better, an injection or carburetor engine?
This issue is quite controversial; each point of view has many opponents and supporters, both among ordinary drivers, and among specialists who fully understand the principle of operation of an injection engine. So, the carburetor engine is distinguished by simplicity and transparency of operation. That is, if the mechanic adjusted the idle speed, then it remained that way.
As for the injection engine, it all comes down to timely maintenance, as well as the quality of the parts used.
Optimal operation of a car engine depends on many parameters and devices. To ensure normal operation, VAZ engines are equipped with various sensors designed to perform different functions. What you need to know about diagnosing and replacing controllers and what are the parameters of the VAZ table is presented in this article.
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Typical operating parameters of VAZ injection engines
Checking VAZ sensors is usually carried out when certain problems are detected in the operation of the controllers. For diagnostics, it is advisable to know what malfunctions of VAZ sensors can occur; this will allow you to quickly and correctly check the device and replace it in a timely manner. So, how to check the main VAZ sensors and how to replace them after that - read below.
Features, diagnostics and replacement of elements of injection systems on VAZ cars
Below we will look at the main controllers!
Hall
There are several options for how you can check the Hall sensor of a VAZ:
- Use a known working device for diagnostics and install it instead of the standard one. If after replacement the problems in engine operation cease, this indicates a malfunction of the regulator.
- Using a tester, diagnose the controller voltage at its terminals. During normal operation of the device, the voltage should be from 0.4 to 11 volts.
The replacement procedure is performed as follows (the process is described using the example of model 2107):
- First, dismantling is carried out switchgear, its cover is unscrewed.
- Then the slider is dismantled; to do this, you need to pull it up a little.
- Remove the cover and unscrew the bolt that secures the plug.
- You will also need to unscrew the bolts that secure the controller plate. After this, the screws that secure the vacuum corrector are unscrewed.
- Next, the retaining ring is dismantled and the rod is removed along with the corrector itself.
- To disconnect the wires, you will need to move the clamps apart.
- The support plate is pulled out, after which several bolts are unscrewed and the manufacturer dismantles the controller. A new controller is being installed, assembly is carried out in the reverse order (the author of the video is Andrey Gryaznov).
Speeds
The following symptoms may indicate a failure of this regulator:
- idle speed power unit float, if the driver does not press on the gas, this can lead to an arbitrary shutdown of the engine;
- the speedometer needle readings float, the device may not work as a whole;
- fuel consumption has increased;
- the power of the power unit has decreased.
The controller itself is located on the gearbox. To replace it, you only need to jack up the wheel, disconnect the power wires and remove the regulator.
Fuel level
The VAZ or FLS fuel level sensor is used to indicate the remaining volume of gasoline in the fuel tank. Moreover, the fuel level sensor itself is installed in the same housing with the fuel pump. If it malfunctions, the readings on the dashboard may be inaccurate.
The replacement is done like this (using the example of model 2110):
- The battery is disconnected and the rear seat of the car is removed. Using a Phillips screwdriver, unscrew the bolts that secure the fuel pump hatch and remove the cover.
- After this, all wires leading to it are disconnected from the connector. It is also necessary to disconnect all the pipes that are supplied to the fuel pump.
- Then the nuts securing the clamping ring are unscrewed. If the nuts are rusty, treat them with WD-40 before removing them.
- Having done this, unscrew the bolts that directly secure the fuel level sensor itself. The guides are pulled out from the pump casing, and the fasteners need to be bent with a screwdriver.
- At the final stage, the cover is dismantled, after which you will be able to gain access to the FLS. The controller is changed, the pump and other elements are assembled in reverse withdrawal ok.
Photo gallery “Changing the FLS with your own hands”
Idle move
If the idle speed sensor on a VAZ fails, this is fraught with the following problems:
- floating speed, in particular, when additional voltage consumers are turned on - optics, heater, audio system, etc.;
- the engine will start to stall;
- when the central gear is activated, the engine may stall;
- in some cases, failure of the IAC can lead to body vibrations;
- the appearance of a Check indicator on the dashboard, but it does not light up in all cases.
To solve the problem of device inoperability, the VAZ idle speed sensor can either be cleaned or replaced. The device itself is located opposite the cable that goes to the gas pedal, in particular, on the throttle valve.
The VAZ idle speed sensor is fixed using several bolts:
- To replace, first turn off the ignition and the battery.
- Then you need to remove the connector; to do this, disconnect the wires connected to it.
- Next, use a screwdriver to unscrew the bolts and remove the IAC. If the controller is glued, then you will need to dismantle the throttle assembly and disconnect the device, but act carefully (the author of the video is the Ovsiuk channel).
Crankshaft
- To perform the first method you will need an ohmmeter, in in this case The resistance on the winding should vary around 550-750 Ohms. If the indicators obtained during the test differ slightly, this is not a problem; the DPKV needs to be changed if the deviations are significant.
- To perform the second diagnostic method, you will need a voltmeter, a transformer device, and an inductance meter. The procedure for measuring resistance in this case should be carried out when room temperature. When measuring inductance, the optimal parameters should be from 200 to 4000 millihenry. Using a megohmmeter, the power supply resistance of the device winding is measured at 500 volts. If the DPKV is working properly, then the obtained values should be no more than 20 MΩ.
To replace the DPKV, do the following:
- First, turn off the ignition and remove the device connector.
- Next, using a 10mm wrench, you will need to unscrew the analyzer clamps and dismantle the regulator itself.
- After this, a working device is installed.
- If the regulator changes, then you will need to repeat its original position (the author of the video about replacing the DPKV is the channel In Sandro's Garage).
Lambda probe
The VAZ lambda probe is a device whose purpose is to determine the volume of oxygen present in the exhaust gases. This data allows the control unit to correctly create the proportions of air and fuel to form a combustible mixture. The device itself is located on the exhaust pipe of the muffler, at the bottom.
The regulator is replaced as follows:
- First disconnect the battery.
- After this, find the contact of the harness with the wiring, this the chain goes from the lambda probe and connects to the block. The plug must be disconnected.
- When the second contact is disconnected, go to the first, located in the exhaust pipe. Using wrench appropriate size, unscrew the nut securing the regulator.
- Remove the lambda probe and replace it with a new one.
The UAZ Hunter model UAZ-315195 with the ZMZ-409.10 Euro-2 engine (409.1000400) and wagon-type cars UAZ-3741, UAZ-3962, UAZ-3909, UAZ-3303 with the UMZ-4213.10 Euro-2 engine (4213.1000400) were installed control system with electronic unit controls MIKAS-7.2: model 293.3763000-04 for UAZ-315195 and model 291.3763000-11 for the UAZ-3741 family.
Composition and components of the UAZ control system with the ZMZ-409 Euro-2 and UMZ-4213 Euro-2 engines and the MIKAS-7.2 controller.
Operating voltage of on-board network direct current, in which all actuators and sensors of the engine control system provide the specified parameters, should be within the range of 10-14.5 Volts, nominal - 12 Volts.
The MIKAS-7.2 controller has a non-switchable supply voltage input to provide a “sleep” mode, which allows you to save adaptive data on self-learning and settings, as well as error codes in RAM ( random access memory) controller after turning off the ignition and the main relay.
Engine control system sensors with MIKAS-7.2 controller.
— Sensor type DS-1, 23.3847000 or 406.3847060-01.
— For ZMZ-409 — sensor DF-1, 406.3847050 or 25.3847000, or 24.3847000, or 406.3847050-03 / -06 / -07. For UMZ-4213 - phase sensor DF-2 with an extended cable, 4213.3847050 / -04.
— Mass air sensor 20.3855 (HFM62C/11), 31602-3877012.
— Damper position sensor DPDZ-01 (NRK1-8) or DKG-1, 406.113000-01 or Bosch 0 280 122 001
— Coolant sensor 19.3828000, semiconductor type, output voltage increases linearly with increasing coolant temperature.
— Air temperature sensor 19.3828000, semiconductor type, output voltage increases linearly with increasing air temperature.
— Sensor 5WK9-1000-G, 31602-3826020
— Sensor GT305 or 18.3855000, 406.3855000
Actuators of the engine control system with controller MIKAS-7.2.
— Four fuel DEKA-1D (ZMZ-6354), or Bosch 0 280 150 560, or Bosch 0 280 158 107, 406.1132711-02, or 406.1132010, or 406.1132107.
— Two two-terminal coils 3012.3705, 406.3705. Paraphase ignition - for cylinders 1, 4 and 2, 3, respectively.
— Regulator for additional РХХ-60, 406.1147051 / -01 / -02. Made in the form of a rotary sector-shutter with a torque two-winding electric drive controlled by a PWM channel of the controller.
— Electric fuel pump module with fuel level sensor 315195-1139020 for ZMZ-409 and 3741-1139020 for UMZ-4213.
— Canister purge valve 2112-1164200-02
— Lamp indicating malfunctions in the engine management system.
— Electromagnetic relay 90.3747 or 90.3747-01.
— Electromagnetic relay for electric fuel pump 90.3747 or 90.3747-01.
— A set of four high-voltage wires 4216-3705090 for the UMZ-4213 engine.
— A set of four high-voltage wires with tips 4052.3707244 for the ZMZ-409 engine.
— Four spark ignitions A14DVR SN474-3707000 or BRISK LR17YC 4062.3707-02 for the ZMZ-409 engine.
— Four spark plugs WR7BC Bosch 0 242 235 522 or BRISK NR15YC-3707000 for the UMZ-4213 engine.
Other control system devices.
— Wiring harness 315195-3724067-10 for the ZMZ-409 electronic engine control system.
— Wiring harness 220604-3724022-10 or 390944-3724022-10 for the electronic engine control system UMZ-4213.
— electronic 85.3802, 315195-3802010-11
— Ignition switch without immobilizer antenna 31514-3704010 for UAZ-315195.
— Ignition switch without immobilizer antenna 3741-3704010 for the UAZ-3741 family.
— Catalytic exhaust gas converter 31602-1206010-03 / -04 / -05 for UAZ-315195.
— Catalytic exhaust gas converter 220694-1206010 for the UAZ-3741 family.
Peculiarities electronic systems control of a UAZ with a ZMZ-409 Euro-2 and UMZ-4213 Euro-2 engine, and a MIKAS-7.2 controller.
All power circuits of the engine control system and associated electrical equipment are protected from possible electrical damage short circuit fusible Power to the engine management system components is supplied from the main relay. The electric fuel pump is switched on from a separate relay.
Separation of ground circuits by functional purpose allows you to provide the required engine control parameters for accuracy and speed in conditions of intense electromagnetic interference created by automotive electrical equipment.
Synchronization of the engine management system with engine mechanics is carried out using crankshaft and camshaft position sensors, installed on the crankshaft and camshaft, respectively.
Control feedback on fuel supply is implemented using an oxygen sensor. Fuel vapors from the tank accumulated in the adsorber are sucked through the valve into the engine inlet. Knock feedback for correcting the ignition timing is implemented using a knock sensor that detects high-frequency engine vibrations.
To power the sensors, the following is used: on-board voltage from the main relay, or voltage from the controller converter. To power the actuators, the following is used: voltage from the main terminals of the on-board network, on-board voltage from the main relay, on-board voltage from the electric fuel pump relay.
Engine load and optimal fuel delivery are calculated based on readings from the mass air flow sensor and throttle position sensor. Gasoline injection is distributed, phased, since a phase sensor is used to mark the beginning of the engine control cycle for the first cylinder. The oxygen sensor heater is turned on from the power circuit of the electric fuel pump; its power is not regulated by the controller.
If a fault is detected in the control system, the controller turns on the fault indicator lamp. External diagnostic equipment connects to the diagnostic socket for information communications with a controller via a bidirectional K-line. It is possible that light codes-flashes of accumulated faults appear on the indicator lamp when the engine is not running.