Knock sensor VAZ 2109 injector

During operation of the VAZ 2109 engine, suboptimal ignition of the fuel-air mixture may occur. This phenomenon negatively affects the power plant, creating increased vibration and exerting parasitic loads on the cylinder-piston group and related components. Detonation gradually destroys the internal combustion engine, bringing the need for major repairs closer. For timely detection of suboptimal fuel combustion, a knock sensor is used. It monitors vibration and sends corresponding signals to the ECU, according to which the operation of the motor is adjusted.

Appearance of the knock sensor

How does he work

Depending on the type of knock sensor used, the operating principle of the device is slightly different.

Type DD

Principle of operation

The control unit controller supplies voltage to the knock sensor. It is constant and amounts to 5V. A resistor built into the regulator lowers this voltage to a reading of 2.5V, and then returns it back. When detonation occurs in the cylinders of the power unit, the knock sensor transmits an alternating current voltage to the controller, the frequency and amplitude of which changes depending on the detonation indicators. Due to this signal, the electronic control unit changes the ignition timing, as a result of which detonation disappears

When the power unit is operating, the regulator sends a signal to the controller in the form of alternating current, which corresponds to the vibration frequency of the motor. If detonation occurs, the signal is converted to a higher frequency. This is how the electronic control unit determines that detonation has occurred. The extinguishing mechanism adapts to the current operation of the engine and allows you to maintain characteristics at an optimal level, adapt to work with fuel, the quality and octane number of which leaves much to be desired.

The best way to avoid all sorts of problems with the engine's fuel injection system is to refuel with high-quality gasoline.

Types of devices

Detonation - what is it?

Detonation is simply improper combustion of the mixture. But if measures are not taken in time, then the detonation of a VAZ engine can have strong negative consequences. The peculiarity of this effect lies in the self-ignition of the combustible mixture due to exposure to high temperatures and pressure in the cylinders.

During normal engine operation, combustion of the combustible mixture occurs in three stages.

Induction, takes place as the piston approaches top dead center. At this stage, a source of flame begins to appear from a spark, which subsequently forms a flame front, and all this is accompanied by a slight increase in pressure in the combustion chamber.
The formation and passage of a flame front through the combustion chamber, as a result of which the bulk of the mixture burns, and this is all accompanied by a sharp increase in pressure and temperature.
Burning out of the mixture residues that remained behind the front, as well as those located near the cylinder walls. It is between the transition from the second stage to the third that detonation may occur. The high temperature and pressure that occurs during the second stage leads to rapid chemical reactions in the unburned mixture, causing it to spontaneously ignite. Such combustion occurs very quickly (up to 1200 m/s) and in the form of an explosion, accompanied by the formation of shock waves that are destructive.

These waves lead to the destruction of the near-wall layers of gases, which ensures an increase in heat transfer, due to which the cylinder walls and other components of the CPG overheat. Also, the blast wave destroys the oil film of the walls, resulting in increased friction between the cylinders and rings. Detonation also has a mechanical effect on the elements of the piston group - a sharp increase in pressure leads to the appearance of shock loads on the piston bottom, valve, and cylinder walls, leading to their damage.

The figure shows how normal and detonation combustion of fuel occurs.

On the left – normal combustion; on the right – detonation combustion

Causes of detonation

Engine detonation can occur for various reasons, among which are:

Use of fuel of dubious quality and origin;
Poor air-fuel mixture entering the cylinders;
Impaired performance or failed engine cooling system;
Using spark plugs whose characteristics do not match the engine parameters;
Formation of carbon deposits inside combustion chambers;
A timing belt that has jumped for one reason or another, etc.

If measures are not taken in time regarding a failed motor, this threatens to impair the functionality of the motor and more.

What does DD failure lead to?

If the knock sensor or its electrical connections fail, the following will occur:

The controller will switch to working according to the backup table for calculating the ignition timing. The consequences of such operation of the device are loss of power of the power unit, increased fuel consumption and engine tripping.

When the motor or its electrical connections grind, detonation increases, which leads to the appearance of a fault code in the controller. As a result, the Check engine light comes on on the dashboard.

Searched device

What to use

When planning to replace the DD, it is important to think about which sensor will be used in the injection system on your VAZ 2109.

As we have already noted, two types of regulators can be used on nines. But each of them has its own operating characteristics.

Broadband piezoceramic devices are capable of recording and transmitting a wide range of noise emanating from the engine to the electronic control unit. As a result, the ECU eliminates the causes of each of them.
Resonance devices are configured only to operate when detonation occurs in the engine.

From the point of view of practicality and efficiency of the knock sensor, the best choice for the VAZ 2109 is broadband. But it's up to you to decide.

Troubleshooting

In order to promptly determine the failure of a device, you need to know some characteristic signs:

a “Check Engine” alert sounds in the cabin;
You can hear knocking fingers when you press the accelerometer pedal sharply;
there is a lack of power, the car accelerates poorly;
The engine overheats very much due to setting the wrong ignition timing.

The knock sensor, the symptoms of which are described above, most often fails as a result of running on low-quality gasoline. Another reason is excessive engine overheating, which may be the result of problems in the functioning of the cooling system. If the reason is contamination and rust, then you can try to clean the element and check its functionality. If the problem is more serious, then the best option would be replacement, especially if we are talking about a two-pin device.

Malfunctions of the knock sensor are most easily determined using a special device. Computer diagnostics allows you to find out the true cause as accurately as possible. If there is a break in the device circuit, then this may indicate several options. Firstly, sometimes the part itself is the problem. Secondly, the case may rust, which will cause a failure. Third, lack of power or control signal. Many motorists, when trying to clean rust, come to the conclusion that it is much easier and faster to replace it.

Replacement

If the DD fails, the only correct solution is to replace the broken device with a new, working regulator. To do this, you must perform the following steps.

Arm yourself with a 13mm socket and ratchet.
Remove the negative terminal from the battery and place it aside for a while. It is necessary to deprive the car of power, otherwise problems cannot be avoided.
Disconnect the block with wires that powers our sensor. To do this, first press the metal latch and then pull the plug.
Next, use a simple wrench or ratchet to unscrew the fastening nut. It is quite inconvenient to work in the area where the knock sensor is located, but it is quite possible to unscrew it without unnecessary problems.
Remove the regulator from the pin and look at the markings on it.
Determining the markings will allow you to find out which version of the sensor is used on your car. It is advisable to replace it with the same one. Or, following the data from the instruction manual for your nine, purchase an analogue that matches the parameters of your power unit on the VAZ 2109.
Having purchased a new sensor, you can install it in place of the failed regulator. Return the negative terminal to the battery and check the operation of your motor. If the problem really was in the sensor, all signs of detonation will disappear.

Unscrew and remove
Buying a DD today is not a problem. But it’s better to choose proven, good auto parts stores. The approximate cost of the regulator is 300 rubles. Perhaps this is the only financial cost when doing a DIY repair.

There are no particular difficulties in replacing such an important device for proper engine operation. Follow the instructions and use only high-quality gasoline. Then the new DD will not bother you soon.

Replacing the sensor

We figured out how to check the knock sensor of a VAZ-2114 or any other model. Please note that this sensor cannot be repaired and if it is faulty, it must be replaced.

Replacing the VAZ-2114 knock sensor is a simple operation, but it can be difficult due to poor access to it (16-valve engines). To change, you just need a new element and an open-end wrench of the appropriate size.

Before unscrewing the mounting bolt, you must first disconnect the block with wires. Then the bolt is unscrewed, the old sensor is removed, and a new one is installed in its place and securely fixed with the same fastener. And only after that the block with wires is connected.

Knock sensor VAZ 2109

Purpose of the knock sensor

The VAZ 2109 car uses two types of knock sensors, depending on the controller used and the year of manufacture of the vehicle. Earlier vehicles used a single-prong resonant meter.

Later on the VAZ 2109 they began to install a broadband DD injector. Despite the difference in design and operating principle, the sensors serve the same purpose: to promptly detect the occurrence of detonation.

The wideband knock sensor is designed in the shape of a torus. In its center there is a mounting hole through which a pin passes. There is a terminal block on the side of the meter. It is designed to connect the sensor to the engine control unit.

The resonant sensor has a thread on one side, thanks to which it is screwed into the hole for the pin. Therefore, this type of meter does not require additional fasteners.

Both knock sensors have a sensing element inside the housing that generates voltage when exposed to vibration. A resonant DD is capable of operating in a narrow range. Broadband picks up vibration during the entire operation of the power unit.

The ECU receives a signal from the DD. The module analyzes the incoming voltage, namely its amplitude and frequency. When a deviation from the specified range is detected, the ECU understands that detonation has occurred. In this case, according to a pre-established algorithm, the operation of the engine is adjusted and the non-optimal combustion of the air-fuel mixture goes away.

Eliminating detonation combustion allows you to reduce the load on the engine, which increases its service life. Therefore, the main purpose of DD is considered to be to extend engine life through timely detection of detonation.

Do-it-yourself diagnostics and replacement of the knock sensor

Don’t know where the knock sensor of the VAZ 2109 is located? Open the hood and look at the engine block. Find the second and third cylinders. A black sensor with one wire is attached between them using a bolt. This is what he is. The reason for the location in this place is that this is where the geometric center of the motor is. Therefore, knocks of the same amplitude in the first and fourth cylinders will cause the generation of signals of equal magnitude.

You can digress from the topic a little and talk about 16-valve engines. In them, the knock sensor is located on the exhaust manifold side. Access to it is difficult, so replacement is problematic without a pit or overpass. But such engines were not installed on the VAZ 2109, so there will be no problems. But let's get back to how to test the device. And you can do this in two ways:

An ohmmeter (tester) with a measurement scale of 2 kOhm is required. Disconnect the wire from the sensor and connect the tester between its output and ground. The resistance should be fixed at the same level. But when hitting the body, the resistance should increase sharply and return to its original value. If the readings do not increase, or do not return to the original value, or there is no resistance at all, we can judge that the sensor is broken.
The second method will be much simpler and, oddly enough, more effective. To check the VAZ 2109 knock sensor, it is necessary (without dismantling or disconnecting the device) to start the engine and set the crankshaft speed to 2000 rpm. Next, strike the VAZ 2109 knock sensor mounting bolt of varying strength. If it is working properly, the crankshaft rotation speed will change (in particular, drop). The reason is a decrease in SOP, since the electronic control unit “sees” the presence of detonation. As soon as the impacts on the bolt stop, the speed returns to normal. But if none of the above happens, then we can judge that the device is broken.

Look at the design of the device. As you can understand, it cannot be repaired. Therefore, you take the faulty one in your hand, swing it well and throw it in a landfill. Buy a new one and forget about your problems. On VAZ 2109 cars it is very easy to replace it.

Please note: on VAZ cars, access to the knock sensor is made difficult by the intake module. As a result, remove the knock sensor by touch. To make the process easier, remove the engine splash guard and dismantle the sensor by approaching it from below the car (on an inspection hole or overpass).

To remove the knock sensor, unscrew the sensor mounting bolt from the cylinder block with a socket wrench. Remove the sensor from the mounting pin and remove it from under the intake module. Disconnect the wire connector from the sensor by pressing the latch.

To check the sensor, connect to its terminals a multimeter turned on in voltmeter mode with a measurement limit of up to 200 mV. To correctly connect a single-contact sensor to the device, connect the negative wire (black) of the device to the ground of the sensor (installation location of the mounting bolt). Connect the positive wire (red) to the signal wire located in the sensor connector. Two-pin sensors are connected with both terminals to the tester wires, observing polarity.

Then use a screwdriver to lightly tap the sensor body, simulating detonation. In this case, the tester should show voltage surges of 40-200 mV, depending on the strength of the shock. If there is any malfunction of the sensor, there will be no reaction to impacts. The sensor should be replaced. Remember that in some cases the devices are not able to detect a weak signal and the voltmeter will indicate a sensor malfunction.

Switch the tester to resistance measurement mode and connect it to the sensor terminals. In this case, it is desirable that the device be able to measure infinitely large resistances. A working knock sensor on VAZ cars should have a very high resistance, tending to infinity.

More accurate checks of the knock sensor are only possible on a special stand. Install the tested sensor in reverse order. Tighten the mounting bolt to a torque of 20-25 Nm.

how to check overheating
Removing and replacing the speed sensor on VAZ 2112, 2111, 2110
Replacing the knock sensor on a VAZ

A knock sensor in a car is a device that is designed to determine the time of detonation in an internal combustion engine. The engine knock sensor is one of the devices in the electronic engine management system of a fuel injected car. To replace a broken device with a new one, you need to do a few simple operations.

Make sure the engine is completely cool before starting this procedure. Disconnect the negative cable from the battery. If the audio system in your car is equipped with a security code, before disconnecting the battery, check that you have the correct combination to put it back into operation.

In foreign cars, the knock sensor is usually screwed into the engine cooling passage, so its disconnection usually involves some loss of coolant. To avoid this, drain the antifreeze from the cooling system in advance. Now disconnect the electrical connector and then remove the sensor from the engine.

Modern sensors are usually supplied with a threaded part that is coated with an anti-seize sealant. Screw the replacement sensor into the standard place. Please note that over-tightening the sensor may cause it to fail.

Connect the electrical wiring to the sensor and fill the cooling system. Check the engine for signs of coolant leaks.

The knock sensor on VAZ cars changes as follows. To remove the single-pin sensor, which is located at the top of the cylinder block, disconnect the electrical connector and unscrew the sensor using a 22mm wrench. Then remove the sensor.

To change the two-pin sensor on the stud, turn on the ignition and disconnect the wire from the negative terminal of the battery, then disconnect the sensor from the block with wires. Now, using a size 13 wrench, unscrew the nut that secures the sensor. Remove the washer and disconnect the device from the stud. Install the new sensor in reverse order.

Sensor cost

On VAZ 2109 cars with “January 4.1” controllers, DD 211203855010-01 is used. It has a low prevalence. Because of this, its price is extremely high. For an original product you often need to pay 1500-1700 rubles. A good analogue is General Motors 21120-3855010-01. Its cost is 1600-2000 rubles.

On the VAZ 2109 with “January 5.1” controllers, broadband DD 21123855020 is used. Its price is 300-450 rubles. Good analogues of the branded sensor can be found in the table below.

Table - Good analogues of the branded VAZ 2109 knock sensor

Manufacturer	vendor code	Approximate cost, ruble
ZAZ	183855	170-290
Phoenix	SD10100O7	230-390
VOLVO	183855	290-410
Bosch	0 261 231 046	370-400
EPA	550489	250-400

Where to look and how to check the knock sensor

In order to check it, you also need to know where the VAZ-2110 knock sensor is located. Everything is simple here; so that it can effectively capture vibrations, it is placed on the cylinder block. Its location largely depends on the design features of the motor itself.

On 8-valve engines it is usually located in the line of sight and is usually easy to get to. Therefore, it is not difficult to determine where the knock sensor is located on a VAZ-2107 (injector). It is installed on the exhaust manifold side and consists of a massive washer with wiring going to it and secured to the engine with a bolt.

But on 16-valve engines, the installation location is slightly different than the location of the knock sensor on the VAZ-2107 (injector). Due to the fact that the block head is much more massive, the sensor is located lower - under the exhaust manifold, so access to it is limited, and often it can only be reached from under the car on an overpass or inspection hole.

And although the location of the motor may differ slightly due to the design of the motor, its connection is always identical. Thus, the connection diagram for the VAZ-2109 knock sensor with an injection engine is the same as on the 2114 model.

Checking the VAZ-2110 knock sensor can be done in two ways.

The first of them implies the presence of a tester switched to measuring resistance (measurement level - up to 2 kOhm).

Checking the knock sensor with a tester

To check, you just need to disconnect the wiring block from the sensor and connect a tester to the sensor contacts. Then you should apply light blows with a wrench to the DD fastening bolt and monitor the readings on the tester display.

Methods for checking a knock sensor

You can indirectly check the performance of the DD by measuring the resistance. A value from 1 to 10 MOhm is considered normal. If the sensor exceeds the specified range, it needs to be replaced.

You can check the DD using a multimeter. To do this, you need to connect the probes to the terminals and lightly tap on the work area. If the multimeter does not detect voltage surges, then the DD is faulty.

The VAZ 2109 with “January 4.1” controllers has a single-contact sensor. To check it, the second probe of the multimeter should be connected to the DD housing.

Self-replacement of the resonant sensor on a VAZ 2109

Replacing the DD on a VAZ 2109 with your own hands is done according to the instructions below.

Unscrew the sensor.

Take out the DD.

Install everything in reverse order.

Symptoms of sensor malfunction

You can determine whether the sensor is broken without a dashboard. But this will require experience and a special approach to your car. You need to know him very well. We list the signs by which you can understand that the device is broken, from here it will be immediately clear what the knock sensor affects:

If you determine the breakdown yourself, then it’s not far to independently diagnose the sensor, as well as replace it yourself. In principle, this is not difficult, but it requires some understanding of the process.

Replacing a broadband knock sensor on a VAZ 2109

To replace the wideband sensor on a VAZ 2109 car yourself, it is recommended to use the step-by-step algorithm below.

Secure the car with the handbrake.
Disconnect the negative terminal from the battery, turning off the power to the vehicle's on-board network.
Disconnect the connector.
Unscrew the nut from the stud.

Remove the knock sensor.

Install a new meter.

Knock sensor for injection engines of VAZ 2108, 2109, 21099 cars

The knock sensor (DS) is one of the elements of the electronic injection engine control system on VAZ 2108, 2109, 21099 vehicles.

Purpose of the knock sensor

The knock sensor is designed to monitor knock in engine cylinders.

Inside the sensor body there is a piezoceramic element (plate) with certain properties (piezoelectric effect) and a resistor. Outside connection block.

Location by car

The knock sensor on VAZ 2108, 2109, 21099 vehicles is installed on the front part of the engine cylinder block. The broadband is on a stud and is secured with a 22 nut; the resonant one is screwed into the hole under the stud.

Operating principle of the knock sensor

Resonant piezoelectric sensor.

The ECM (control unit) supplies the DD with a constant voltage of 5V. The resistor built into the sensor lowers the voltage to 2.5V and returns it back (the voltage at the sensor output). When detonation occurs in the engine cylinders, the DD begins to output an alternating current voltage to the controller with an amplitude and frequency that varies depending on the magnitude of the detonation. Based on this signal from the sensor, the controller adjusts the ignition timing to dampen detonation.

Wideband piezoceramic sensor.

While the engine is running, the sensor sends an AC signal to the controller corresponding to the engine vibration frequency. When detonation occurs, the sensor produces a signal with an increased frequency. The ECU detects the occurrence of detonation.

The detonation damping mechanism is adjusted to the operation of the engine and allows it to maintain its power characteristics at a normal level, and also allows it to adapt to operation on fuel with a lower octane number.

Detonation occurs due to increased temperature in the engine cylinders. Its reasons: the use of low-quality fuel, a lean fuel mixture, a faulty cooling system, the use of spark plugs that do not correspond to this type of engine, carbon deposits in the combustion chambers, a skipped timing belt, etc.

DD malfunctions

If the knock sensor fails or its electrical connections malfunction, the controller switches to backup tables for calculating the ignition timing. As a result, engine power decreases, fuel consumption increases, and the engine “troubles.”

A sensor malfunction or exceeding the operating limits of the detonation damping system (detonation is too large) leads to a fault code being written into the controller’s memory and the “Check Engine” lamp in the instrument panel coming on.

Applicability of the knock sensor on VAZ 2108, 2109, 21099 cars

VAZ 2108, 2109, 21099 vehicles use both resonant and broadband piezoceramic knock sensors. Broadband detects and transmits the entire spectrum of engine noise to the ECU. And that, in turn, detects detonation noise. The resonant sensor is configured to operate only when engine detonation occurs.

For VAZ 2108, 2109, 21099 with controllers January 4.1 (2111-1411020-22), GM ISFI-2S (2111-1411020-10 (20, 21)), BOSH M1.5.4 (2111-1411020) – knock sensor 2112- 38550102112-3855010-01 (resonant).

For VAZ 2108, 2109, 21099 with controllers January 5.1, VS 5.1 (2111-1411020-72), BOSH MP7.0N (2111-1411020-40), BOSH M1.5.4N (2111-1411020-60) – sensor 2112- 3855010-01 (broadband).

Notes and additions

Piezoelectric effect - a mechanical effect on a piezoelectric element causes its electrification and the occurrence of an electric current. When engine vibrations occur, the piezoceramic plate inside the sensor is subjected to mechanical stress (compressed), a potential difference arises at its ends, and an electrical signal is sent to the controller. In this case, the sensor is axial, i.e. it converts axial movement (shocks from the engine).

More articles on the injector of VAZ cars

Video - causes and consequences of detonation

Among all devices, the VAZ 2109 knock sensor occupies a special place; it is responsible for the correct regulation of the fuel mixture and setting the ignition angle. On modern cars you can find two types of sensors - resonant and broadband. Which type to install on your machine is up to you. But you need to know the characteristics of each. The operating principle of the devices is generally the same.

The operation is based on the piezoelectric effect. When subjected to mechanical action (in particular, impact), an electrical charge is generated. And its value is higher, the stronger the blow. From here you can understand the whole meaning of the device. Resonant knock sensors consist of:

Piezo element.
A constant resistance that suppresses the 5V supply voltage to an operating value of 2.5V.

During normal operation of the engine, shocks occur, but their amplitude is the same and is not registered by the sensor due to the built-in resistance. Only when mechanical stress increases does some of the signals begin to pass through to the input of the electronic control unit.

More advanced broadband ones - they record all, even small, vibrations of the engine block. There are vibrations when the motor is running, but the sensor sends a signal of equal amplitude. As soon as detonation knocks begin, the frequency of the generated signal increases. And the electronic control unit understands that the detonation phenomenon has begun.

The ECU begins to analyze the fuel map to bring the engine to normal operation. In addition, thanks to this symbiosis of electronic means, it is possible to ensure that the engine functions normally on low-octane gasoline without consequences. But this does not mean that you can drive on such fuel all the time. It is necessary to note other causes of detonation knocks:

Incorrectly installed timing belt.
Malfunctions in the cooling system.
The presence of a large amount of carbon deposits in the combustion chambers.
Poor quality spark plugs.
Lean air-fuel mixture.
Using low-grade gasoline.

Sensors VAZ 2109 injector

Injection engine options installed on the VAZ 2109 models, as well as the later VAZ 21099, VAZ 2110, VAZ2112, etc., have a number of undeniable advantages. However, the normal functioning of such power units largely depends on the normal operation of various sensors. Having at least minimal knowledge about the operating principle of these sensors, their location, possible malfunctions, as well as the features of their replacement, can greatly facilitate the life of owners of these car brands.

Coolant temperature sensor

Structurally, this sensor is a thermistor, the resistance of which varies depending on the ambient temperature. The main characteristics of the engine depend on its readings, and its malfunction can lead to engine overheating, increased fuel consumption, difficulty starting a hot engine, and many others. Finding where the coolant temperature sensor is located is not too difficult - it is located on the outlet pipe of the engine block head near the thermostat. Replacing the sensor will require first draining the coolant and removing the air filter.

According to its purpose, this measuring element is designed to record abnormal vibrations in the engine body and its operating principle is based on the piezocrystalline effect. Failure of this sensor manifests itself in the appearance of “dullness” of the engine and a noticeable increase in fuel consumption. The sensor is located in the upper part of the cylinder block and its replacement does not require special professional skills. Beginning car enthusiasts should take into account that VAZ cars can be equipped with both resonant-type knock sensors (in the form of a barrel) and broadband meters (in the form of a tablet), which are not interchangeable with each other.

Throttle position sensor

— It is a potentiometric meter, a sensitive element, which is attached to the throttle valve and, accordingly, information about its position is supplied to the ECU. This sensor is a very unreliable element and a trivial washing of the car can lead to its failure. Malfunctions of the throttle position sensor can be manifested by increased speed at idle, jerking during smooth changes in movement, and engine stopping when changing modes. The sensor is located on the side of the throttle assembly. When installing it after replacement, you should remember the need to install a safety foam ring.

Sometimes it is called a lambda probe and it is attached to the exhaust pipe of the muffler. The main purpose of this element is to monitor the oxygen content in the exhaust gases and, based on its readings, the amount of fuel supplied to the engine is adjusted. Failure of the oxygen sensor can lead to increased fuel consumption and poor CO2 performance. Replacing an oxygen sensor is quite simple, however, when performing this technological operation, you should not forget that the body of the lambda probe is equipped with a permanent plug with a section of wiring that is often damaged due to inexperience; in addition, you should be careful when putting on the protective silicone cover (in the wrong position it can melt ).

— placed on the gearbox directly between the speedometer drive and the tip of its flexible shaft. In its work, it uses the Hall effect and its impulse information, provided for processing by the central control unit, is proportional to the wheel speed. In addition to the traditional disappearance of speed information provided to the driver, the failure of this sensor can lead to a slight deterioration in overall road performance. On VAZ cars, the cause of failure of this sensor is often oxidation of the contacts in its connector.

Crankshaft position sensor.

The value of this sensor is very large and it generates information proportional to the change in the angular position of a special disk attached to the engine crankshaft. It is on the basis of this information that the cylinder that currently requires fuel and spark supply is determined. The sensor is located on the oil pump cover and its failure can lead to the engine stopping or, at a minimum, cutting off the speed in the range from 3500 to 5000 rpm.

In conclusion, I would like to note that, unfortunately, one of the weakest points of AvtoVAZ products today is the condition of various connections and in case of problems with the VAZ 2109, VAZ 2110, VAZ 212, VAZ 2114 sensors, before checking, dismantling or replacing one or For another sensor, it is useful to first evaluate the condition of its connector, contacts, integrity of the wires, and whether all the necessary gaskets are in place.

Examination

Today, VAZ 2109 car owners use two methods to check the condition of the coolant temperature sensor. Let's say right away that the second one is more reliable, but the first one is easier. Decide for yourself which of the methods presented below to use.

Verification method

Your actions

According to the table, check whether the resistance corresponds to that required at a particular temperature of coolant or boiling water.

Temperature (in degrees Celsius)

Resistance (Ohm)

If there are deviations from the norm, we conclude that the sensor no longer performs its functions properly and therefore requires mandatory replacement.

Replacement

Device and location

The knock sensor is enclosed in a housing, inside of which there is a plate - a piezoceramic element. This element is characterized by certain properties called the piezoelectric effect. Plus there is a resistor in the case. The power supply is connected to the sensor externally.

The device is located in the front part of the cylinder block of the VAZ 2109 power unit. It can be broadband or resonant. The first is located on a stud, secured with a nut size 22. The resonant type of sensor is screwed into the hole located under the stud.

Location

How does he work

Depending on the type of knock sensor used, the operating principle of the device is slightly different.

Type DD

Principle of operation

The best way to avoid all sorts of problems with the engine's fuel injection system is to refuel with high-quality gasoline.

Types of devices

Consequences. Fighting methods

Detonation of a carburetor engine is accompanied by the appearance of a metallic knock, especially under load. Many people perceive it as the “ringing of fingers” of the pistons, but the distinct sound, as if metal is hitting metal, is due to the blast wave.

The consequences of this effect, if no measures are taken, are very serious. Overheating of the component parts can lead to breakdown of the block head. The absence of an oil film, which is destroyed due to the effects of detonation, increases friction and leads to accelerated wear of the CPG elements. And finally, the mechanical impact of the shock wave together with high temperature can cause the piston to burn out, destroy the bridges between the rings, bend the connecting rod, and burn out the valve plates.

Consequences of detonation combustion of the mixture

Features of injection engines There are several ways to effectively combat this effect on carburetor engines. First of all, when detonation occurs, the fuel should be replaced, especially if the fuel was previously refueled at a station with questionable fuel quality. If the fuel does not cause suspicion, then it is worth checking the ignition and setting a later advance angle by turning the distributor.

The causes of detonation in an injection engine are identical to that of a carburetor, but in addition to metallic ringing, such engines have a number of other signs indicating the occurrence of this effect.

And all because the engine with such a power system is more advanced. Its processes of mixture formation and supply of mixture to the cylinders are controlled by an electronic control unit based on the readings of many sensors. Also, depending on the operating mode of the engine, he also independently selects and sets the advance angle. That is, the driver can no longer set the ignition on his own.

The electronic unit is able to track the occurrence of detonation. For this purpose, all injection engines are equipped with a knock sensor (DS).

This sensor is capable of detecting the appearance of detonation combustion, and the ECU will take action based on its data. For example, if the cause of detonation of a VAZ-2109 engine equipped with an injection power system is low-quality fuel, and the sensor detects the effect, the ECU will simply reduce the ignition timing and the detonation will stop.