Checking and replacing the switch on a VAZ 2108, VAZ 2109, VAZ 21099 car. VAZ 2108 ignition switch

The contactless ignition system of the VAZ 2109 includes a switch, as well as spark plugs, a distributor (distributor), a coil and an ignition switch. The system is designed to supply a spark that ignites the air-fuel mixture into the combustion chamber. It is very important to supply the spark at exactly the right moment in the compression phase of the mixture.

Advantages of contactless ignition

There are a lot of advantages to this type of system; among the main advantages is enviable reliability. A small number of elements is the key to long and stable operation. But the most important thing is the absence of high currents and mechanical breakers. This is the main difference between the electronic type and the classic contact type, which was installed on the VAZ 2107 of the first releases. Of course, it is far from the accuracy of a microprocessor system, but a distributor that does not have a contact breaker can improve the performance of the motor.

So, we can highlight the following advantages of using a contactless system on the VAZ 2107 and similar models:

1. Reduced fuel consumption due to more correct setting of the ignition timing and greater spark power.
2. Increasing the stability of the internal combustion engine. The crankshaft speed is constant, there are no interruptions.
3. Increased reliability, since there is (virtually) no mechanical interaction, and there are no spark gaps.
4. Reduced costs for components. The Hall sensor, for example, fails much less often than the breaker contact group.

Signs of a faulty switch: how to check the switch yourself.

Purpose and design features of the switch.

A switch is one of the elements of a car's electrical equipment. His task

– ensuring normal operation of the contactless ignition system. The assembly is fastened in the engine compartment.

The device is reliable, able to withstand severe vibrations and shock loads

This is very important, because the switch housing contains sensitive electronics

At the heart of the VAZ switch

– standard L 497 microcircuit, which controls an “NPN” type transistor.

>Scheme feature

– possibility of programming by the user and setting the required delay coefficient. Starting a cold engine directly depends on the correctness of this indicator.

Thanks to precise settings

, you can speed up the crankshaft rotation speed (while eliminating failures in operation) and guarantee high-quality traction of the power unit.

The main parameters of the switch device include:

Voltage range – from 6 to 16 Volts; operating voltage level – 13.5 Volts; ensuring an uninterrupted spark when the crankshaft rotates in the range from 20 to 7000 rpm; switching current – ​​from 7.5 to 8.5 A.

Signs of a faulty switch.

One of the main symptoms of a faulty switch is loss of spark.

. The engine starts hard and stalls from time to time, causing interruptions in operation.

But don’t rush into replacing it - it’s important to make sure of the reason, because loss of spark can occur for a number of reasons - failure of the Hall sensor, broken timing belt, faulty ignition coil, poor contact in the distributor cap, wiring problems, and so on

Therefore, first of all, a comprehensive diagnosis is necessary. The fastest and most effective way in this case can be a car diagnostic scanner. Most of this type of device is quite easy to use and has an affordable price.

Of those presented on our market, we can recommend paying attention to the multi-brand scanner Scan Tool Pro Black Edition

The advantages of this model include diagnostics of not only the engine, but also other components. Compatible with 99% of new and old cars since 1993, quite easy to use and has wide functionality.

If diagnostics of other nodes does not produce results

, then we can move on to our “hero”. But how to check the switch, since the device has a very complex design?

How to check the switch yourself.

Most car enthusiasts don’t bother with diagnostics and simply install a new unit. This method has its advantages.

Firstly

, there is no need to waste time checking - just install a new part.

Secondly

, you can immediately determine whether this is the reason or not. In fact, there is no need to be afraid of the work, because checking the switch takes a few minutes.

So, to carry out work at home, a test lamp (nominal voltage should be 12 Volts) and a standard set of keys are enough.

With their help, you can verify the presence or absence of pulses, and later make a decision about the serviceability of the device itself.

Algorithm for checking the switch:

To begin work, it is advisable to disconnect the battery so as not to accidentally short-circuit the wiring that you will unscrew.

Using an eight-point wrench, unscrew the nut and remove the wiring from the ignition coil marked “K”. This wire is easy to recognize - it is brownish in color and goes to the terminal labeled one on the switch;

Connect this wire through a control light to terminal “K” on the ignition coil, and then connect the battery;

Turn on the engine starter and observe the lamp's actions. If it blinks, then the switch is working. If the light bulb does not show any signs of life, then the only way out is to replace the device.

If there are doubts about the serviceability of a part, the check should be carried out on a special stand (there is always one at the service station).

In this case, it is possible not only to determine whether the product is working, but also to measure the duration of the pulses.

When the first suspicions appear, you should not immediately change the switch or spend money on a specialist. You are quite capable of doing the job yourself.

Moreover, now you know how to check the switch on the VAZ 2109 and other models of the domestic brand. All that remains is to allocate time and prepare a minimum set of tools. Have a good trip and of course no breakdowns.

Diagnostics of device health

It is recommended to carry out in-depth diagnostics of the device at a specialized service. A professional stand will allow you to evaluate the condition of the unit in various engine operating modes in the range from 0 to 8000 rpm. The manufacturer categorically does not recommend diagnosing using artisanal methods. This is dangerous not only for the car’s electrical system, but also for the person trying to carry out such diagnostics.

If the car’s dashboard is equipped with a voltmeter, and the car owner knows how to check the VAZ switch, then a simple way is available to him to preliminary assess the performance of the device. One of the functions of the switch is to turn off the power to the ignition coil when the engine is not running but the ignition is on. With such a shutdown, the voltage in the on-board network increases noticeably. This means that to check the functionality of the device, you should insert the key into the lock, turn it to the ignition position, but do not turn the starter. At this time, you must carefully monitor the readings on the voltmeter.

In the first seconds, the arrow will freeze approximately in the middle of the scale, and after 8-10 seconds it will noticeably move to the right. Since the device worked, the coil turned off, the voltage increased, and the voltmeter responded, then everything is in order. If a switch fails, it usually happens entirely. It is unlikely that the secondary function remained operational, but the basic one failed. So, with a high probability, the device can be considered working.

Malfunction of the ignition system of the VAZ 2109

Checking the ignition system.

Malfunctions of the VAZ 2109 ignition system are determined by the presence of a spark discharge on high-voltage wires and spark plugs. To check the spark discharge for safety and clarity purposes, it is better to use a spark gap. With its help you can adjust the spark gap, which cannot be done with a spark plug. The ignition system is considered operational if the spark penetrates a distance of 10 mm. and has a blue color.

The first step is to check the spark on the center wire. If available, check on any two spark plug wires. If there is a spark on only one wire, then the reason is that the slider is turning and it needs to be replaced. If there is no spark on any spark plug wire, then the reason is a breakdown or cranking of the distributor slider. To check, remove the distributor cover and slider. In the runner bushing, with which it is mounted on the shaft, check the integrity of the boss, which fits into the slot of the shaft and prevents the runner from turning on the shaft. If it is working properly, put the slider in place, remove the central wire from the cover socket, holding it with pliers at a distance of 2 - 5 mm from the slider, and crank the engine with the starter. The presence of a spark discharge between the wire and the slider indicates its breakdown.

There is no spark on the center wire.

Let's return to checking the spark on the central wire if there is a malfunction in the ignition system of the VAZ 2109 and consider the case of the absence of a spark on the central wire. The reason for this may be a malfunction of the switch, a hall sensor in the distributor, a lack of power to the electrical equipment of the ignition system, a broken timing belt, a malfunction of the ignition coil, a break or short circuit between each other or to the housing of the connecting wires.

Checking the switch.

You can most likely check the switch using the arrow of a voltmeter if it is installed on the instrument panel or connect a voltmeter to the supply wires of the ignition system. When the ignition is turned on, the voltmeter begins to show the voltage of the on-board network, and after a while, about 10 - 15 seconds, the needle should deviate even further indicating an increase in voltage. This occurs due to the switch disconnecting the ignition coil, which occurs if the crankshaft does not start rotating.

If there is no voltage increase, then you need to check the presence of power at the ignition coil terminal of the switch. To do this, disconnect the connector from the switch, turn on the ignition, connect one end of the indicator lamp to the car body, and touch pin 4 on the connector with the other. If the control lamp is on, then power is supplied to the switch. Touch the test lamp to pin 1 of the switch connector. If the control lamp is on, then there is power to the ignition coil and the primary winding of the coil is intact. If the warning light does not light, check the power at the ignition coil terminals. The presence of power at terminal “B” and absence at the second terminal indicates a break in the primary winding of the ignition coil, and the presence of power at both terminals indicates a break in the wire from the coil to the switch.

If there is no power at pin 4 of the connector and terminal “B” of the ignition coil, it is necessary to check the contact group of the ignition switch. To do this, check for power on the blue wire with a black stripe. If there is power on it, eliminate the break in the wires or poor contact in the connections in the circuit from the ignition switch to the ignition coil and the switch.

Verification procedure

If you detect one or more signs of “dying” of the coil or if it is impossible to start the engine, you should definitely check its performance. This is necessary in order to find out what nature of the breakdown occurred, and, therefore, begin to eliminate it. Can this be done without instruments? Unfortunately no. Unless you immediately replace the coil with a known good one. At the very least, a regular multimeter will suffice. Such a tester must be kept in the car - its cost is almost symbolic.

In general, verification is relatively easy. It is enough to follow the steps described below, and even a completely inexperienced car enthusiast can handle it.

First of all, you need to inspect the ignition unit itself. If the engine does not start at all, then you need to find out if there is a spark. You need to do this:

• disconnect the main wire from the distributor (located in the center);
• connect a candle to it;
• holding it with pliers, apply it to the motor housing or to the breaker;
• turn on the ignition.

If there is no spark, there is only one conclusion - failure in the coil. Next, you need to find out whether electricity is supplied to it.

The check is carried out with a multimeter. One of its probes is applied to terminal “B” on the coil, the second to ground. If there is no voltage after turning on the ignition, the fault is looked for directly in the lock.

In addition, it is also possible to power the coil using an emergency circuit. Here the wire from the positive terminal of the battery is connected to contact “B”. In this situation, you can be absolutely sure that voltage is supplied. However, when these actions did not lead to a spark, you will have to test the primary winding for integrity.

• the wiring located on its sides is disconnected (they are low-voltage);
• the multimeter is set to Ohms and the resistance is measured;
• The secondary winding is also ringed in the same way.

Replacing the ignition switch on a VAZ 2108, VAZ 2109, VAZ 21099

Where is the ignition system switch located? Its location is very simple, and all because it is located at the very top of the car engine, and it is very easy to get to. The switch is located near the vacuum booster, and it is attached to the car body with two nuts, so that you visually know its location, see the photo below:

When do you need to change the ignition system switch? If it fails, the engine may experience the following malfunctions:

• Firstly, the car’s engine may not operate steadily, both at idle and when driving the car.
• And secondly, very often there can be a loss of car throttle response; in other words, the car will drive worse.

Repair and replacement instructions

It is worth noting that modern Russian switches are suitable for output key transistors not only of standard production, and in particular KT890A, KT898A1, but also the foreign analogue BU931. It can be implemented either without a housing or in the TO-220 or TO-3 design.

As for the control circuit, the 78.3734 series switches are suitable for:

• 4-channel amplifier type K1401UD2B;
• domestic microcircuit R1055ХП1;
• foreign L497B SGS-TOMSON.

Before replacing the switch or its components, it is recommended to test the integrity of the wiring and connections of the ignition system. Pay special attention to the generator. It is also a good idea to check the voltage from the on-board network to the Hall sensor.

More details on faults and how to repair them are given in the table below.

How to replace the ignition system switch on a VAZ 2108-VAZ 21099?

Removal: 1) First remove the negative terminal from the battery. (You can read how to do this in the article: “Replacing the battery”, in the “first” paragraph)

2) Then disconnect the wire block from the switch by hand.

3) Next, use a wrench to unscrew the two side nuts that secure the switch to the car body.

Note! There will be a ground terminal under the left nut, so when the nut is unscrewed, disconnect this terminal from the switch!

4) And at the end of the operation, when the block is disconnected and the two side nuts are unscrewed, remove the switch from the car.

Installation: 1) First, install the new switch in its place, and then tighten the side nuts that secure it.

Note! Before you start screwing the left nut, install the ground terminal in the place where it will be screwed first, and only after that screw the left fastening nut!

2) Next, insert the wire block into the connector of the new switch.

3) And then, finally, install the “minus” terminal that you removed earlier on the battery.

Checking the ignition system switch for serviceability:

1) To do this, first disconnect terminal “K” from the ignition coil by unscrewing the nut that secures it with a wrench

(Be sure to read the “Important” paragraph at the end of the article)

2) Next, using a test lamp, which is designed for “12 Volts”, with a power of “3 W”, check the coil for serviceability for this:

• First, connect the previously disconnected terminal to the control lamp.
• And then connect the other contact that comes from the control lamp in place of the “K” terminals on the ignition coil.

And then, turning the engine over with the starter, check whether the lamp lights up or not.

Note! If it does not light up, then replace the ignition coil with a new one!

Important! On the very first ignition coils, instead of the “K” marking, the “+” marking was drawn, and therefore, if this is the case on your coil, then in this case, disconnect the wire next to which the “+” marking is located and not “K”!

Alternative diagnostic methods

When there is no voltmeter on the dashboard, you can get out of the situation by doing everything yourself. To do this, you will need a 12 V light bulb and two meter wires with stripped ends. The diagnostic work flow diagram is as follows:

There is another simple and reliable way to identify a device malfunction. To do this, you need to install a known-good switch, start the car and check the functionality of the system in all modes. If the system is working normally, then the problem was precisely the failure of this device, and when the same failures occur, the switch has nothing to do with it.

The disadvantage of this method is that you need to have a spare working switch with you. While this is reasonable for long journeys in uncrowded areas, it is exotic for regular city trips.

How to check a VAZ 2108-2109 switch

Warm Siberian greetings to everyone. I want to share with you that the switch is different from the switch. A new one, just from the store, may be worse in terms of parameters than the replaced old one, which was previously thrown into the trunk. I will also show how the switch is responsible for the power and duration of the spark.

After the release of my videos on YouTube on repairing, adjusting carburetors and diagnosing injection cars. I started getting a lot of questions. In order to communicate more closely with my subscribers and viewers, I began to conduct these streams. Subscribe. Press the bell. Ask your questions - I will be happy to answer them in more detail than in writing.

Sources

• drive2.ru/l/564176184837932184/
• vaz-russia.com/remont-vaz-2108/zamena-kommutatora-zazhiganiya-na-vaz-2108-vaz-2109-vaz-21099.html
• twokarburators.ru/kommutator-vaz-2108-2109-21099/
• ladaautos.ru/vaz-2109/kak-mozhno-proverit-kommutator-vaz-2109.html

ABOUT THE POSSIBILITIES OF MODULE REPAIR

Most breakdowns of this device lead to its replacement, but sometimes it is possible to repair the ignition coil to return it to service. This is especially true in cases where moving or tapping changes the behavior of the motor. If you have the ability to use a soldering iron and a multimeter, you can try to get it back into operation.

You need to remove the metal back cover, under which the electrical parts of the module are filled. You need to try to carefully get rid of the silicone and its “insides” will be revealed to your eyes. Find broken or “bad” contacts and solder them.

After this, close the back cover and check its functionality. If the repair result is positive, you need to open it again and fill the inside with silicone.

If the result is negative, then the block must be replaced. True, owners with extensive amateur radio experience continue to “dig” further. You can try replacing the electronic switches. Basically, these two elements become the culprits of failures of the engine starting system.

Malfunctions of the contactless ignition system of VAZ 2108, 2109, 21099 cars

Sometimes when diagnosing a carburetor gasoline engine of a passenger car, difficulties arise in determining the cause of a particular malfunction. This happens because the symptoms of their manifestation are very similar. For example, carburetor malfunctions and ignition system malfunctions will have almost the same effect on engine performance. In this article we will try to understand what problems in the operation of a car engine arise due to a malfunction of the ignition system.

Car engine does not start

— Battery is faulty

— The switch is faulty

— Hall sensor is faulty

— The insulation of high-voltage wires is “broken”

— The distributor cover is “broken” or is heavily oxidized, its contacts are destroyed

— Ignition distributor rotor (slider) burnt out

— The ignition coil is faulty or its cover is “broken”

— High-voltage wires are connected in the wrong order

— Defective spark plugs, their insulation is “broken,” the gap between their electrodes does not correspond to the norm

— Incorrect ignition timing

Ignition is either too early or too late. How to correctly set the ignition timing on VAZ 2108, 21081, 21083 engines is described in detail on the page “Setting the ignition timing of VAZ 2108, 2109, 21099 cars.”

— The low voltage circuit of the ignition system is faulty (contacts have oxidized, wires are broken, connectors have come off...)

Read more about the inability to start the carburetor engine of VAZ 2108, 2109, 21099 cars in the article “The carburetor engine does not start (reasons related to the ignition system).”

For comparison, you can see what reasons exist that the engine cannot be started due to a carburetor malfunction.

The car engine runs erratically (troits) or stalls at idle

— The gap between the electrodes of the spark plugs does not correspond to the norm

— Heavy carbon deposits on the spark plug electrodes

— Defective spark plugs (“insulator broken”)

— Incorrect ignition timing

— The switch is faulty

— The centrifugal ignition timing regulator in the distributor is faulty (weights stick, their springs are weakened or broken, damper rings are lost)

Causes of rough idle related to the carburetor are outlined on the “Rough Idling” page.

Dips and jerks in engine operation

— Incorrect ignition timing

— The gaps between the electrodes of the spark plugs do not correspond to the norm

— Defective spark plugs

— The noise suppression resistor in the rotor (runner) of the distributor burned out

— Wear or damage to the contact carbon in the distributor cover

— Current leakage through “broken” insulation of high-voltage wires, spark plug insulator, ignition coil cover

For the causes of malfunction related to the carburetor, see the page “Failure when pressing the gas pedal.”

The engine does not develop full power, its throttle response is reduced

All of the above causes of malfunctions lead to loss of power, throttle response of the car engine, and increased fuel appetite. You can only add

— Malfunction of the vacuum ignition timing regulator in the distributor due to jamming of its plate

Notes and additions

Five more articles on the site on the ignition system of VAZ cars

How to check a VAZ 2109 switch

The switch is the very part of the car’s ignition system that can easily fail, but is difficult to diagnose. Is this really so? Let’s find out using the example of a VAZ 2109 car. Let’s consider why it is needed and how to check it in case of a malfunction of the ignition system.

Purpose of the VAZ 2109 switch The switch is an electronic unit that is responsible for programming and controlling the vehicle’s ignition system. Its basis is the well-known L497 microcircuit, which is used to control transistors. The advantages of using a switch over conventional contact ignition are reliability, since the electronics make it easier to start the engine even at the lowest temperatures, which indicates good sparking. In addition, the switch is securely mounted, which ensures trouble-free operation. With proper adjustment of the switch, you can increase the rotation speed and speed of the engine crankshaft and directly influence its traction properties. Correct operation of the switch is ensured through the use of a Hall sensor installed on the engine distributor. Signs or symptoms of a bad switch? Perhaps the main symptom of a block failure is the absence of a spark when starting the engine. This happens as follows: the starter successfully rotates the engine, but the mixture does not ignite. The engine shows absolutely no signs of life at all. Spark plugs are usually wet and quickly fail. First of all, all other elements of the system are checked - these are armored wires, Hall sensor, ignition coil and spark plugs. In addition, it is necessary to ensure that the timing system is in good working order. If everything is in order, it’s time to check the switch on the VAZ 2109. How to check the switch? First, you need to find out some characteristics of the device in order to avoid mistakes during diagnostics.

The device voltage ranges from 6 to 16 Volts. Operating (standard) voltage is at least 13.5 Volts. Switching current is 7.5-8.5 Volts. Guarantee of a good spark at rpm from 20 to 7000.

This is what characterizes the good performance of the device. If at least one of these points is missing, then the switch has become unusable. And now about checking the device. First you need to take a size 8 key and unscrew the nut securing the wire to contact “K” on the ignition coil. As a rule, it is brown in color. Try not to let it come into contact with the car body, as this may cause a short circuit. Now you need to take a 12-volt test lamp and connect one end of it to contact “K” and the other to the brown wire. Ensure good contact - this will be the key to competent diagnosis of the problem. Make sure the lamp is visible from inside the car. Get behind the wheel, turn on the ignition and try to start the engine. If the light blinks while the engine is cranked by the starter, it means the switch is working. If the lamp does not light up at all, then the device must be replaced. If you have the slightest doubt about the serviceability of the device, you can take it to a service station. There is a special stand that will not only determine the operation of the switch, but also measure the length of the pulses and compare them with the nominal value. High-precision instruments allow for broader diagnostics, but this costs a lot of money. Fortunately, the cost of a new device is not so high - only 300-400 rubles. It is recommended to carry a spare switch in the glove compartment of your car. This will help avoid many troubles in the event of a sudden breakdown of the device. We wish you good luck on the roads!

VAZ switch check video

Scheme and principle of operation of BSZ

We connect a 12 V light bulb instead of the coil.

For an analogue of the foreign microcircuit LB, see

To have an idea of ​​what this gadget looks like and what to look for, you can look at a photo of the switch on our Internet portal.

They have contacts that can burn or simply wear out. The controllers also control the electrovalve of the economizer of forced idling EPHH. The use of semiconductor and microprocessor switches in contact-transistor or contactless ignition systems allows you to obtain the following advantages: the current flowing through the breaker contacts is reduced, as a result of which they practically stop burning for a contact-transistor ignition system; the duration of the spark supply increases, which guarantees effective ignition of the working mixture in the engine cylinders; it becomes possible to significantly increase the compression ratio in the engine cylinders, as well as the crankshaft rotation speed, without compromising the reliability of spark formation.

Choke L1 and resistor R1 are designed to speed up the process of closing transistor VT1, capacitor C1 of the primary excitation circuit of the ignition coil and capacitor C2 serve to protect the components of the switch circuit from voltage surges in the vehicle's on-board network. The protection circuit of the output transistor is made on discrete elements C7 and R. The voltage is supplied to the main distribution contact, then through the wiring it goes to the spark plugs, which form a spark.

Check for a spark when the ignition is turned on. It is a hybrid of electronics and mechanics. The electronic part includes a commutator and a coil. A cover is attached to the top with latches, where the cables from the spark plugs are connected.

The distributor body should be turned to the desired position and secured with a nut. Tighten the distributor fastening nut, install the cap and spark plug, then start the engine. But with the help of spark plugs alone, the engine will not be able to run.

The spark plug cables are connected according to the numbering on the cover, the central wire is connected to the coil electrode. If there were no annoying errors during the installation process, the car will start immediately

For comparison, look at the contact system. Checking the Hall sensor Measure the voltage at the sensor output

Repair and maintenance What is a switch in a car? Automotive electronics course. Switch

Electronic ignition connection diagrams: VAZ 2101-VAZ 2107

Scheme of a contactless ignition system for VAZ cars:

1 - switch; 2 — ignition coil (bobbin); 3 — distributor; 4 — ignition key; 5 - Hall sensor.

How contactless ignition works

The sequence and principle of operation of the BSZ is as follows:

1. The driver turns the ignition key.
2. The circuit is closed and constant voltage from the battery is supplied to the primary winding of the ignition coil. The energized primary winding forms a magnetic field around itself.
3. When the starter starts, it begins to rotate the crankshaft of the internal combustion engine and rotates the shaft, which is located inside the distributor along with the slider.
4. The hall sensor detects how the distributor shaft rotates (along the protrusion on the shaft) and transmits a signal to the switch.
5. The electronic unit turns off the voltage supply to the primary winding based on the signal from the Hall sensor.
6. When the voltage supply circuit is interrupted, at that moment a high voltage pulse of up to 24 kilovolts appears in the secondary winding of the coil, which is transmitted through a thick wire to the slider (the moving part of the distributor).
7. Fixed contacts are built into the roof. The runner throws an impulse onto one of these stationary contacts. From the contact that received the high voltage pulse, it is transmitted through high-voltage wires to the spark plugs of those cylinders in which the pistons are at top dead centers.
8. When voltage is applied to the spark plug, the working combustion chamber of the cylinder already contains fuel and air in a compressed state for ignition.
9. The distributor slider rotates to spark all spark plugs according to a certain sequence pattern: 1-3-4-2. Depending on how to install the slider, the entire operation of the system depends, early ignition or later, we learned to determine in another material.
10. The car engine starts.

Diagram of an outdated VAZ ignition system (without switch)

1 — distributor (distributor); 2 - breaker; 3 - capacitor; 4 — ignition coil (bobbin); 5 - battery; 6 — ignition switch; 7 - spark plugs.

This scheme is in systems where there is no switch. The circuit is broken mechanically using a breaker.

Disadvantages of contact ignition:

1. The contacts burn and oxidize, which reduces the power to create a spark.
2. There are wear parts that are recommended to be changed every 20 thousand km. mileage
3. Converted power in contact systems is up to 18 kilovolts. For electronic or contactless ones - up to 24 kilovolts.

SZ scheme

The ignition system used on the VAZ 2109 includes the following components:

• Switch;
• Candles;
• Distributor sensor;
• Ignition coils;
• Switch;
• Locking device. It does not allow the starter to turn on until the ignition is completely turned off;
• Locking and anti-theft device;
• Hall Sensor;
• The sensor-distributor roller, which is located horizontally and receives torque from the camshaft;
• System of spontaneous ignition shutdown, which is activated after 2-8 seconds;
• Switched current equalization system, which is required when the network voltage changes within the range of 6-18V;
• The system built into the switch, which regulates the time of energy accumulation in the coil, limits the current strength at low motor operating frequencies.

The ignition system operates with a voltage of up to 26 kV, the spark charge has a duration of 1.6-2.0 milliseconds, and the energy released during this time is 35-50 MJ.

Service

If you do not monitor the state of the system and lose sight of the presence of malfunctions and malfunctions, this can lead to certain consequences. Namely:

• Reduced reliability of the operation of the protective equipment, the occurrence of failures;
• Reduced technical characteristics of the engine, such as acceleration dynamics, maximum speed;
• A sharp increase in the amount of fuel consumed;
• Failure of SZ elements or the entire system.

Before you carry out maintenance on the SZ yourself, take into account several important recommendations.

1. Do not touch the ignition coil with your hands while the engine is running. This applies to wires, switch and other components.
2. Do not test the SZ for performance using the “spark” method, as this can lead to injuries and costly repairs of the entire vehicle;
3. Under no circumstances should you start the engine with a spark gap between the central terminal of the distributor sensor and the high voltage.

Switch Specifications

The VAZ switch circuit is based on the L497 microcircuit, which controls the output NPN transistor. A special feature of the microcircuit is the ability to program the recovery time of the delay coefficient, which is important for trouble-free starting of a cold car power unit. This feature of this electronic component of the switch allows for rapid acceleration of the crankshaft speed without failures in operation, which ensures constant engine traction.

Analogues that are sometimes used in the design of the VAZ 2108 switch are the KR1055HP1, KR1055HP2, KR1055HP4 microcircuits. However, these electronic components are found quite rarely in the design of the device. Main technical parameters of the device:

• optimal operating voltage 13.5 V;
• voltage range for normal operation 6-16 V;
• switching current 7.5-8.5 A;
• the range of ensuring uninterrupted sparking is from 20 to 7000 crankshaft revolutions.

https://youtube.com/watch?v=PUSP30fdAqM

The design of the device is designed for use in single-wire power circuits on cars in which the body plays the role of a negative terminal. Installation of a device mounted on the L497 chip is carried out in a specially designated place using standard fasteners.

Existing types of switches

There are two main types of devices: AC CDI and DC CDI. The first switches were small and simple, using a high-voltage generator in their circuitry. The latter are more common, equipped with four contact groups with minus and plus, as well as separate outputs for the coil and Hall sensor. But the latter function only in the presence of high voltage supplied from an external source.

Switches are also usually classified according to their functional features:

• traditional or stock devices that strictly correspond to the parameters of the car - as a rule, they are installed from the factory;
• sports - they have the ability to increase the upper limit of the number of revolutions of the internal combustion engine, however, this type is the lot of experienced specialists and has the risk of accidents;
• with the ability to adjust the phases of the UZ - an excellent option when you need to equalize the torque of the power plant, improve acceleration characteristics and stabilize engine operation at different speeds.

Of course, switches are usually divided into main types.

Electronic

This type of switch is also called a microprocessor switch with transit keys. It is used to control the converter voltage and reduces the load on the connections, thereby increasing the current capacity.

• possibility of better filling of internal combustion engine cylinders;
• efficient engine output at all speeds.

Hybrid

These systems additionally use a mechanical part - a cam distributor. The electronics are represented by the switch itself and the coil. The unit is very reliable, economical and convenient. For example, if a switch fails, you can switch to an old converter with a slider.

Contactless

A group with transistors, widely used since the early eighties. It replaced the antediluvian classical contact systems. At one time it was considered the most effective, since its performance indicators were much higher than those of other switches.

Dual channel

The same contactless system, but significantly modernized. For example, a conventional BSZ has the same disadvantages of a KSZ - loss of spark energy, instability of idle speed, limitation on adjustment of the SPD, high sensitivity to pollution and humidity. A two-channel system or DBSZ eliminates these disadvantages from the ignition system, providing even higher spark energy through the use of additional coils. Also, problematic moving elements - a slider and a coal - are not used here, and the lid serves only as a protective element. Therefore, it is not subject to burnout.

Interestingly, two-channel ignition was used before. This was implemented on export VAZ-21083. However, switches of this type, also called dual-circuit switches, were not widely used due to the poor quality of the electronics of that time.

One more nuance regarding switches. They may have different outputs. Those with the default number “1” are extremely dangerous for the ignition coils at the moment they experience malfunctions. But the advantage of such devices is that standard converters for contact ignition can be integrated with them.

Contactless ignition system

In total, there are three huge groups of systems - contact, contactless, microprocessor. The first is divided into two subgroups - contact and using a transistor operating in switch mode. Transistors are also used in the design of a contactless ignition system. This scheme began to be actively used in the early 80s of the last century. And it has a number of advantages, which will be discussed below. The switch circuit is simple; it can be implemented both on transistors and on a controller.

But the contactless ignition system also has many disadvantages when compared with a microprocessor one. The latter allows you to control almost all engine parameters. BSZ does not allow this; it also cannot be used normally on injection engines. The reason for the obsolescence of the contactless system lies not only in the development of electronics and the automotive industry, but also in the adoption of stringent measures to ensure the environmental friendliness of internal combustion engines. Unfortunately, only microprocessor control can reduce the amount of harmful substances in the exhaust.

Price

More details in the table.

And finally, remember that when replacing a powerful switching transistor, it is important to pay attention to the quality of fixation of the part to the switch body. Many beginners make mistakes here or do not apply enough heat-conducting paste. As a result, the device cannot be repaired.

A characteristic feature of the car can be considered its rapid obsolescence, but long life. The most modern car today, in at least two years, will be inferior to other, newer cars with improved characteristics. But even now there are cars from the last century on the roads. Therefore, it is not just interesting, but sometimes necessary, to know at least in general terms what such vehicles are, their structure, features, including such a thing as a simple ignition switch, which significantly changed the capabilities of the car.