Connector to the idle speed control (4 terminals) injector for VAZ 2112-2115, Niva

Many car owners unwittingly became acquainted with the mysteries of the idle speed sensor on their VAZ 2114. The real name of the controller is the idle speed controller (IAC). This is a complex unit in the system of injection engines, which is commanded by electronics (among motorists, “brains”). In case of incidents with IAC, the engine begins to “act up”, causing discomfort and troubles to the driver. Next, we will tell you where the idle speed sensor of the VAZ 2114 is installed, what signs indicate its error, and how to change the IAC yourself.

Device

Modern automakers use 3 types of idle speed sensor: solenoid, rotary and stepper. For VAZ 2114–2115 the latter type is used. IAC is a stepper mini-electric motor that opens/closes the air duct of the intake manifold of the internal combustion engine, thereby regulating the speed (similar to a bolt on a carburetor).

The IAC design has a ring magnet, a lead screw (needle) and 2 windings. When voltage is applied to the magnet and windings, an electromagnetic field appears. As a result, the lead rotor begins to rotate, thereby driving the lead screw through the worm gear. Depending on the position of the rotor, the needle valve is able to control the opening/closing of the air duct of the intake manifold.

For reference. What is a step? This is the distance between the conical shut-off valve (IAC tip) and the intake manifold. It is measured by the number of full rotations of the rotor.

Nuances of choice

The stores offer a huge number of different sensors from different manufacturers. The original part must be marked XX-XXXXXXX-XX. By the last two digits you can figure out compatibility. So, numbers 01 and 03 are interchangeable, and 02 and 04 can also be swapped. Instead of 02, you cannot put 01 or 03. If the sensor is original and new, it is better to additionally lubricate the spring and rod with thick lubricant.

When buying a sensor, even in a trusted store, you should look at the following nuances:

• there are no marks on the packaging by which the manufacturer can be distinguished;
• the sticker on the device body is yellow and has no frames;
• the needle has a dark tip;
• the o-ring is thin and black;
• rivet heads less than 3 mm in diameter;
• white spring;
• The length of the body is 1 mm less than the length of the standard AvtoVAZ sensor.

All these nuances indicate that a counterfeit VAZ-2109 idle speed sensor is being offered. You can see photos of real and fake devices above.

Principle of operation

The balanced relationship of the injection engine components is adjusted by the electronic unit (ECU). When you turn the ignition key on a VAZ 2114, the IAC needle closes the air hole on the manifold. After the engine starts, the ECU calculates the required number of steps and sets the regulator needle to the working position, slightly opening the air channel to lean the mixture.

Taking into account the engine temperature and the position of the needle, the ECU regulates the further operation of the internal combustion engine. On a cooled VAZ-2114 engine, the idle speed sensor will again close the air valve, thereby enriching the mixture and increasing the speed.

For reference! The number of steps is determined by the software (firmware). For example, on a hot engine with a “January 5.1” controller it is usually 110 shg., and on a Bosch - 50 shg. Maximum stroke 250 shg.

Appearance and location

DXX is responsible for adjusting the idle speed. Hence the other name - idle air control. Externally, the device is a miniature electric motor, at the end of which there is a small cone-shaped needle.

Where is he located? The IAC is attached to the throttle body using two screws or regular varnish. Next to the DHW there is a throttle position sensor. Therefore, there should be no problems finding the sensor.

Fault marker and cause

It is very difficult to calculate the breakdown of the IAC. The VAZ on-board computer is primitive and cannot always detect a failure in the system. The owners do diagnostics several times, but there are no errors on the scanner. At the same time, the car works poorly, and the “Check Engine” is stubbornly silent. The owners of the “four” had no choice but to use samples and replace spare parts to determine the cause. Thanks to them, the main symptoms of a malfunction of the idle speed sensor are now known:

• poor starting of the internal combustion engine, especially in winter;
• floating engine speed when hot, in the range of 850–1100;
• the engine freezes if you put the gear in neutral or release the gas;
• The firmware reduces the speed to 800–900 on a cold internal combustion engine (less than 40 °C), without waiting for it to fully warm up.

The main reason for DX failure is natural wear and tear. As a rule, wear appears in the lead screw and rotor. Due to backlash, the ECU cannot accurately adjust the needle pitch. Sometimes the winding burns out as a result of a short circuit. But the most common reason is contamination of the cone valve.

Dismantling the IAC

Dismantle the regulator as follows:

1. Block the car with a handbrake or wheel chocks.
2. Remove the terminals from the battery.
3. Disconnect the connecting connector from the IAC.
4. Clean the area around the IAC from contamination.
5. Unscrew the 2 mounting screws.

Having completed all these operations, the regulator is removed from the mounting socket.

Which to choose

If symptoms or diagnostics confirm that the idle air regulator on your VAZ 2114 is defective, then all you have to do is go to the store for a new sensor. Independent auto industry experts and service workshop specialists recommend purchasing an original IAC. Its number is 2112-1148300-02 (sometimes ending: 01, 02, 04). If there is no factory part, then you can replace it with a worthy analogue.

Table 1. Price of idle speed sensor on VAZ 2114

Source: autopiter.ru

In addition to the above, the products of the manufacturers “Omega” and “KZTA” have proven themselves well.

How to check IAC

There are a lot of counterfeits on the spare parts market. Popular parts are often counterfeited in poor quality. Even some car owners have complaints about Omega, although the majority of VAZ users praise this manufacturer’s IAC. Sometimes you come across outright dummies. Therefore, service workshop specialists are recommended to organize a check of the idle speed sensor before installation on the VAZ 2114.

Self-diagnosis will require a multimeter, which should be switched to an ohmmeter. The IAC has two windings, and there are four outputs on the block: A, B, C, D. First we test A and B (first winding), then C and D (second winding). For model 2112-1148300-02 the natural resistance is 51 (±2) Ohms, and for 2112-1148300-01 - 53 (±5) Ohms. If the parameters on the multimeter tend to infinity, then there is probably an open circuit in the winding circuit.

Attention! The needle on the new regulator should stick out from the body no more than 23 mm, that is, be in a half-closed position. If it protrudes strongly from the body of the regulator, then during installation the splines of the lead screw can be damaged. Car service specialists will help you return the needle to the lower position.

Examination

To check the IAC, you will need a multimeter with which you will measure voltage and resistance.

Checking the circuit

First you need to check the sensor's power circuit. To do this, remove the connector from the IAC and turn on the ignition on the car, set the switch on the multimeter to measure a DC voltage of 20V. We connect one multimeter probe to the motor housing, and the other to terminal A on the connector, the multimeter should show a voltage of at least 12V. Then we connect the probe to terminal D; the multimeter should also show at least 12V.

Sensor check

Checking the sensor involves measuring the resistance of the regulator itself. To do this, switch the multimeter switch to measure resistance with a limit of up to 200 Ohms. We connect the probes to terminals A and B, D and C, the resistance on them should be approximately 50 Ohms. Then we connect the probes to terminals A and D, B and C, the resistance between these contacts should be infinite.

If any of these parameters differ when checking your IAC, it must be replaced.

Replacement

Before you begin replacing the idle air control on a VAZ 2114, you need to prepare. It is better to carry out repairs in a well-lit garage, since on a 1.6 engine (16 valves) you will have to “unfasten” the throttle assembly. On 8-valve engines, craftsmen do without dismantling this mechanism. But sometimes the screws cannot be unscrewed (especially the lower one), so you have to disconnect the fuel supply unit from the manifold, and at the same time clean the dirty channels.

To replace the IAC yourself, you will need a simple set of tools: a durable medium-sized Phillips screwdriver, a 13 mm wrench (head), WD-40 lubricant, aerosol carburetor cleaner and a rag. There is a gasket between the throttle body and the intake manifold. Quite often it is in poor condition due to prolonged use. It’s better to buy a new one in advance (price 30–40 rubles). Step-by-step instructions for replacing the IAC VAZ 2114 (8–16 valves) look like this:

1. Secure the car with the handbrake.
2. Remove the negative terminal from the battery.
3. Remove the engine protective screen (for 1.6).
4. Loosen the clamps on the crankcase exhaust pipe and the corrugated pipe.

5. Disconnect the corrugation from the throttle assembly.
6. Remove the upper idle crankcase ventilation pipe.
7. Remove the throttle cable.
8. Unscrew the 2 nuts of the throttle assembly and remove it from the studs.
9. On the left, below, find the location of the IAC.
10. Unplug the power plug from the sensor.
11. Unscrew the 2 screws of the regulator using a Phillips screwdriver.
12. Clean the assembly from carbon deposits and dirt using carburetor cleaner.
13. Coat the rubber ring of the regulator with machine oil.
14. Install the IAC into the throttle mechanism.
15. Collect everything in reverse chronology.

Attention! Once you have finished replacing the idle speed sensor, do not try to start the car. First you just need to turn on the ignition and wait 10–15 seconds. The system will automatically adjust the IAC to the operating position. Then it is recommended to repeat the operation 3-4 times (masters call this “registration”). Only then can you start the car, warm up the engine and evaluate its performance.

How the sensor works

The throttle assembly has special channels for air flow, which are used only when the engine is idling.

The main air flow into the engine enters through the throttle valve, but when operating at idle, it is closed and the air passes through a special channel, which is opened by the IAC valve.

The sensor receives signals from the ECU and opens the channel to the required amount, thereby regulating the air flow at idle and mixing air with fuel to form the fuel mixture necessary for the operation of the internal combustion engine.

Where to buy car accessories

Spare parts and other products for the car are easily available for purchase at auto stores in your city. But there is another option that has recently received significant improvements. You no longer need to wait a long time for a parcel from China: the AliExpress online store now offers the opportunity to ship from transshipment warehouses located in various countries. For example, when ordering, you can specify the “Delivery from the Russian Federation” option.

Follow the links and choose:

Checking the serviceability and restoring the functionality of the IAC

Check the functionality of the regulator as follows:

1. Connect the battery to the vehicle's on-board network and, holding the IAC in your hands, put the power supply block in place.
2. Turn on the ignition. In this case, the regulator rod should retract inward and then extend back to a certain distance. If the IAC acts this way, then it is operational. Otherwise, it must be replaced.

Sometimes the functionality of the regulator is restored after cleaning the spring, valve hole and needle.

Clean the IAC with a cleaner like WD-40. In this case, there is no need to disassemble the device - just treat the rod, needle and spring with a solvent. It also doesn’t hurt to spray the cleaner inside the XX channel, which will clear the valve hole of any contaminants. As soon as the cleaner dries, the functionality of the regulator is checked again and only after that a decision is made on the advisability of replacing it.

IMPORTANT! Before installing a newly purchased or repaired IAC, it is recommended:

Make sure the product matches the vehicle ECU firmware; check functionality; Lubricate the spring and rod with grease.

When choosing an IAC VAZ2109 injector, avoid purchasing counterfeit products. A fake is distinguished by the following characteristics:

• information on the packaging does not allow identifying the manufacturer;
• yellow color of the sticker on the product body;
• dark tip of the locking needle;
• thin sealing ring.

The figure below will help you distinguish the old-style sensor (on the right) from the new-style sensor (on the left):