The VAZ idle speed sensor is working. How to recognize a faulty pxx

If there are problems with the operation of the idle speed sensor, difficulties may arise with controlling your VAZ 2109. To determine the breakdown and learn how to correctly change the sensor, we will introduce you to the basic principles.

Principle of operation

It is not entirely correct to call the idle speed sensor a sensor. After all, they are measuring instruments that process and convert information, displaying it on mechanical or electronic indicators on the dashboard.

It is correct to call the idle speed sensor a regulator, or simply IAC. IAC plays an important role in engine operation, as it ensures the harmonious and correct behavior of the power unit.

Alas, the self-diagnosis systems on the VAZ 2109 are not perfect, therefore, when the idle air regulator fails, the car does not notify you about it even by turning on the Check Engine warning light. Therefore, you have to navigate by signs of breakdown.

The IAC works as follows. When the ignition switch is turned on, the rod on the sensor extends all the way and rests against a special hole in the throttle pipe. The IAC begins to read the steps and the valve returns to its original position. When the engine is running, increasing or decreasing the number of steps causes a change in the volume of air entering through the hole. Consequently, the required amount of air flows into the engine, ensuring stable operation of the engine at idle.

Functions

The IAC regulates the amount of air entering the engine when the throttle valve is closed. This suggests that the IAC performs the functions of automatically adjusting the specified engine speed when idling.

The regulator also takes part in the process of warming up the engine to optimal operating temperatures in winter. The operating temperature range of the IAC is quite wide - from -40 to +130 degrees Celsius.

The IAC, despite such important functions, is small in size and consists of three main elements:

• Stepper electric motor;
• Spring;
• A rod with a cone-shaped needle at the end.

The idle speed control is mounted on the throttle body with a pair of screws.

Symptoms of a problem

Under no circumstances should you ignore signs of failure of the idle speed sensor on your injection or carburetor VAZ 2109. This will make driving uncomfortable at first, but can soon cause a serious accident.

There are several main symptoms that may indicate problems with ICC:

• The revolutions spontaneously begin to increase and decrease;
• When turning on a cold power unit, the speed does not increase;
• When using additional electrically dependent devices, such as headlights or a heater, the speed immediately begins to drop at idle;
• When shifting gears or idling, the engine may stall.

This is not a complete list of possible symptoms, but they are all indirect. Therefore, to make sure that the problem lies precisely in the IAC, and not in other engine components, it is necessary to check the current state of the sensor.

Checking status

To check the current state of your IAC on a VAZ 2109 car, follow several sequential steps.

Having determined that the old idle speed sensor has already served its purpose on the VAZ 2109, it needs to be replaced. The procedure is completely doable without outside help.

Replacement or cleaning

Practice shows that in a fairly large number of cases, simply cleaning the idle air regulator allows you to restore its functionality. Therefore, we advise you to try this method first. And if it does not give results, then it will not be difficult to replace the device.

1. Buy a container of carburetor cleaner. In this case, your engine may well be fuel-injected. It’s just that this composition is excellent for cleaning IACs and more.
2. Disconnect the connector with wires from the sensor, unscrew the two fasteners and remove the affected regulator itself.
3. Clean the regulator from accumulated debris and contaminants, and be sure to clean the needle and spring itself. This should be done with carburetor cleaner. Use available tools to tidy up a fairly compact device.
4. Be sure to clean the idle air control housing on the throttle assembly. This is where the cone-shaped needle of the XX sensor enters.
5. After completing the cleaning of the device, return it to its place and check its operation.
6. If cleaning does not bring the desired result, the engine continues to behave inadequately, you will have to purchase a new regulator and install it in place of the old sensor.
7. Before replacing, be sure to turn off the power to the car by disconnecting the negative terminal from the battery, then disconnect the block with the power wires, unscrew the mounting screws and remove the device.
8. Reassemble in reverse order.

A faulty idle speed sensor in a VAZ 2110 can create many problems when driving a car. It would seem, what troubles can arise in idle mode? Let's try to figure it out.

Design, purpose and principle of operation

Let’s immediately make a reservation that all cars, whether domestic or imported, tend to break down. This is natural, because each part has its own service life. But any breakdown is not the end of the world, but a completely solvable problem. Sensors are classified as measuring instruments; they convert measured physical quantities into electrical signals and display digital data on a display.

The main purpose of the idle speed sensor (IAS) is to change the crankshaft speed by adjusting the clearance and changing the amount of air passing through. Therefore, it would be more correct to call it an idle air control (IAC). It is a component of the engine and is of great importance for the normal operation of the car as a whole.

The VAZ idle speed sensor (photo 1) consists of a stepper motor, a spring and a rod ending in a conical needle. Using two threaded screws, the VAZ idle speed regulator is attached to the throttle body. When the car owner turns the key in the ignition, the rod extends, resting against the mounting hole: the sensor reads the steps and the valve returns to its original position.

How to identify the problem?

Malfunctions in the operation of the device are difficult to identify, because the VAZ idle speed sensor is not covered by the general monitoring system, and if there is a malfunction in its operation, the “Check-Engine” indicator light does not signal. But some characteristic symptoms suggest that the idle speed sensor is faulty, for example:

• unstable idle speed;
• when the gearshift lever is set to neutral, the engine stops involuntarily;
• The idle speed decreases noticeably when other devices (heater, headlights) are turned on;
• involuntary increase or decrease in speed, regardless of engine operating mode;
• When a cold engine starts, it becomes difficult to reach higher speeds.

There are several ways to check the idle speed sensor on a VAZ 2110. Let's look at some of them.

1. Checking the voltage going to the regulator. We put the car on the handbrake or install anti-roll bars to prevent it from rolling. Disconnect the sensor from the wire block. We check the presence of voltage with a conventional voltmeter: the negative probe is on the engine, the positive probe is on the terminals of the connecting block, wires A and D. Turn on the ignition and analyze the measurements obtained. The operating voltage must be at least 12 V. If it is less, there may be a problem with the battery charge. If there is no voltage (open circuit), we check the electronic control unit and the entire circuit.
2. Measuring circuit resistance. We analyze terminals A and B, C and D one by one - a working sensor will produce 53 Ohms. We measure Ohms in pairs B and C, A and D - the resistance if the IAC operates correctly will be infinitely high.

We repair it ourselves

You can clean the DXH or replace it with a new one in case of malfunction with your own hands. These actions do not require any specific knowledge or skills. You buy carburetor cleaner in a store. Then place the car on a level surface, open the hood and find the IAC on the throttle body. Disconnect the power wire from the negative terminal of the battery to prevent a short circuit. After releasing the plastic latch from the idle speed sensor, the block with wires is disconnected.

Using a Phillips screwdriver, unscrew both mounting screws. Remove the sensor. Then the spring and cone needle of the IAC VAZ need to be cleaned of debris and dirt. The mounting hole on the throttle assembly should also be cleaned. Dry the sensor and put everything back. Checking. If you do not notice any improvement in engine performance, which indicates a faulty regulator, then proceed to replace it.

De-energize the on-board system, disconnect the block, unscrew the fasteners and remove the sensor. Clean the air channel of the throttle assembly and the surface for installing the sealing ring from dirt. Check the seal for cracks and abrasions. If they are present, it is better to replace with a new one.

Wipe the O-ring with engine oil and place it on the hole in the throttle assembly. Insert the new sensor all the way and screw it on. Attach the block. Put on the negative terminal. After installing the device, it must be calibrated. To do this, turn on the ignition for 10 seconds. The ECU will calibrate the DXX on its own.

From this article you will learn what the VAZ 2110 idle speed controller is. This is a device that allows you to control an internal combustion engine using a microcontroller unit. Of course, this element can break. Therefore, it is necessary to carefully study its structure, as well as diagnostic methods. Please note that if the IAC fails, the engine will not be able to function normally. But it’s worth talking about all the details in more detail.

General information

What does RHH do?

As mentioned above, the regulator allows you to change the air supply. If you are familiar with the fuel system of the VAZ 2110, then you know that in it the mixture is formed in the ramp. A certain pressure is maintained there, which is sufficient for high-quality injection of the gasoline mixture into the combustion chambers. It is quite difficult to adjust the air. Especially with the throttle fully closed. Please note that it is with the help of the VAZ idle speed regulator that the engine is warmed up to operating temperature. After all, injection engines do not have a choke lever. Consequently, the air supply is adjusted using only the IAC. This is exactly what the idle speed regulator of the VAZ 2110 does. It does not work while driving.

How does the regulator work?

When the ignition is turned on, the rod on the idle speed control moves. It extends all the way. At the same time, it rests against a special hole in the throttle assembly. Then the rod returns to its original position. At the same time, the regulator is calibrated. When the engine is running, decreasing or increasing the number of governor steps causes a change in the volume of air that passes through this calibration hole. In this case, the amount of air supplied to the fuel rail is sufficient for normal engine operation at idle. This is how the idle speed regulator of the VAZ 2110 and any other car works. This device is very small in size; it can easily fit in the palm of your hand. It has three main elements. Firstly, it is a stepper motor. Secondly, this is the rod on which the cone-shaped needle is located. Thirdly, there is a spring that allows the thing to return to its original position. The device is secured using two bolts.

Symptoms of IAC failure

It is worth noting that the VAZ 2114 idle speed controller is similar in principle to all devices of this type. Of course, there will be a lot of troubles if the idle air regulator suddenly breaks down or starts working incorrectly. Symptoms such as spontaneous changes in crankshaft speed can be noted. For example, a sudden increase in speed or a drop occurs. If you start a cold engine, but the speed does not increase, then you can judge that the IAC has failed. It is also worth paying attention to the fact that when you turn on the headlights or heater, the idle speed should not decrease. Also, the engine often stops if you switch off the gear. For example, when changing from one gear to another or stopping.

Diagnosis of IAC

To check the idle speed control of the VAZ 2110, you will need to prepare the car for repairs. The first step is to disconnect the connector that connects the regulator to the power supply system. After this, you need to check if there is voltage. There are two wires in the block on which voltage must be present. Of course, this must be done with the ignition on. If the voltage is too low, then the reason most likely lies in the charging of the battery. If there is no voltage at all, then look for a malfunction in the electronic control unit or in the power circuit of the idle speed regulator. Next, you need to check the resistance between the terminals of the regulator itself. On average, this resistance should be 53 ohms. You can then remove the sensor, connect it to the connection block, and then apply power. In this case, the cone-shaped needle should gradually extend, and after reaching the extreme position it should return to its original position. On a car, the idle air regulator is diagnosed in the same way.

Bringing such a component of the fuel system as the idle speed of the VAZ 2110 to normal operating parameters remains always relevant for the entire time the car owner uses the vehicle.

Idling in a car with a carburetor

Adjustable idle speed (XX) VAZ 2110 carburetor includes such main parts as:

• channel for supplying gasoline from the float chamber;
• idle speed fuel jet;
• idle air jet;
• passageway;
• outlet channel for gasoline;
• idle speed sensor.

Gasoline enters through the main fuel line, then through the XX nozzle to supply fuel. The next stage is the diffusion of a mixture of gasoline and air masses. In this case, the air flow passes through a special line in the main jet.

Then the resulting mixture of air and fuel droplets is transmitted through the carburetor channels to the XX fuel supply adjusting screw, after which it is enriched with air masses from the bypass line. Then, through the outlet channel, the mixture enters the intake manifold of the fuel system.

Idle speed defects VAZ 2110

The bulk of malfunctions in the gasoline supply system are the idle speed of the VAZ 2110, the indicators of which are “read” by the XX sensor located on the car’s throttle valve.

Here is a list of the main malfunctions indicating incorrect operation of this component of the carburetor system:

• the engine involuntarily “stalls” when the gear shift lever is placed in “neutral”;
• the engine operates unstably, intermittently at low speeds;
• drop in power unit speed when operating at idle speed when additional electricity consumers are turned on (optics, heating stove, interior lighting, etc.);
• the “engine” does not start when idle speed increases, when the vehicle is started on a cold power unit that has not reached operating temperature;
• unauthorized decrease or increase in engine speed at different periods of its operation.

Self-adjustment of idle speed in carburetor “tens”

The accepted pattern for the extremely low value of the frequency parameters of the crankshaft rotation of the “engine” is 800±50 rpm, the limiter has a factory seal. If the idle speed of the VAZ 2110 drops, and when rotating the bushing cannot restore the tachometer readings, you should unseal and unscrew the factory template.

If the idle speed of the VAZ 2110 “floats”, then using the screw for the quantitative composition of the fuel mixture we adjust the required frequency value of the crankshaft torque, and using the screw that changes the quality of the mixture we select the permitted concentration of carbon monoxide emissions.

Important: when you press the gas pedal, the “engine” reacts by proportionally increasing the frequency value of the crankshaft rotation, and when you release the accelerator, it maintains stable idle speed.

When the quantity screw moves in the direction of the clock mechanism, the crankshaft speed increases, and when the quality screw is adjusted in the same direction of movement, the carbon monoxide content in the exhaust becomes less.

Adjusting idle speed on injection engines

Work on adjusting idle speed on VAZ 2110 injection engines takes place according to the following scenario. In the “VAZ 2110 injector idle speed” system, to optimize the crankshaft rotation speed, an Idle Speed ​​Controller for the RXX brand engine, nomenclature designation 2112-1148300, is used.

This integral fuel system component includes a stepper motor and a valve integrated into the throttle body's air flow bypass. If the number of idle revolutions changes, then the working body of the valve (moving rod), at the command of the electronic control unit, changes its physical parameters along the length.

Operating principle of IAC

This fuel system device operates according to the following algorithm. As soon as the VAZ 2110 has a high idle speed, the controller gives a command to open valve XX, directing the air flow bypassing the throttle valve.

To reduce the frequency value of the crankshaft rotation, he programs the unit to close, while the degree of saturation of the air flow transmitted past the throttle valve decreases.

Checking the idle speed regulator of a VAZ 2110 car for functionality is carried out as follows:

1. Disconnect all battery terminals to completely de-energize the vehicle.
2. We interrupt the contact between the harness block and the idle speed regulator coming to it.
3. Using a professional multimeter, we measure the resistance of the external and internal windings of the IAC, while the resistance parameters of contacts A and B, and C and D should be 40-80 Ohms.
4. If the instrument scale is zero, it is necessary to replace the IAC with a working gadget, and if the required parameters are obtained, we check the resistance values ​​in pairs B and C, A and D.
5. The device must detect an “open circuit”.
6. With such indicators, the IAC is serviceable, and if they are absent, the regulator must be replaced.

When purchasing an IAC, you should carefully study the contents of the box, since counterfeits are very common on the market. Their use can lead to serious engine damage, which will require a large amount of money to fix. How to distinguish an original from a fake is shown in the photo above.