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.
Diagnostic methods
Before proceeding with the replacement, we recommend that you really make sure that the cause of all problems with your VAZ 2114 is the faulty IAC. To do this, there are two main ways to check the status of the device.
Explore both to see which diagnostic option is best for you.
Visual inspection
First you need to conduct a visual inspection. In this way, you can detect body defects, needle wear, and carbon deposits. If deposits form, you can clean them with carburetor cleaner. It is also recommended to clean the entire throttle body as it is in a similar condition.
Using diagnostic programs
The operation of the IAC can be checked using a diagnostic adapter and special programs. For example, you can use the simplest ELM327 adapter and the OpenDiagMobile program. In the program menu you need to select the desired position of the XX regulator and watch the operation of the valve. It is better to set it at least 20 steps more than the current position.
Checking the regulator resistance
To do this, we will need to measure the resistance between terminals A, B, and C and D after disconnecting the sensor terminal. We move the multimeter to the position of measuring resistance at the limit of 0-200 Ohms (Ω).
The normal value is within 50-55 Ohms. The resistance between A and C, B and D must be infinity.
Checking with throttle assembly
There is another way to diagnose IAC. To do this, you will need to remove the throttle assembly from the studs along with the sensor.
By connecting the valve connector and turning the ignition on/off, you can observe the operation of the IAC live. See how the needle works, if it is rubbing somewhere, check the evenness of the stroke, hear suspicious sounds.
Wiring check
For this we need a multimeter. With the engine off, remove the connector from the sensor. We set the measurement limit on the measuring device to 0-20 V DC voltage. We measure the voltage at the connector. Normally it should be 12V.
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.
The important role of a small device in a serious unit
Participating in the general algorithm of operation of the vehicle’s electronic system, the IAC is designed to automatically supply a certain amount of air when the throttle valve (DZ) is closed. Thus, it maintains the set idle speed (ISR) of the engine, preventing it from stalling when the gas pedal is released and the gearshift lever is in neutral position. The operating principle of the UDS is as follows:
- the amount of air entering through the remote control is controlled by a mass (total) air flow sensor - mass air flow sensor;
- receiving information from it, the controller (electronic control unit) regulates the supply of the required amount of fuel to the fuel injectors (Fuel Injection) of the car;
- he, using the data from the crankshaft position sensor (DPKV), controls the IAC in accordance with the required speed;
- automatically sets the speed when the engine warms up.
Having safely got out of the intersection, you need to make sure that this regulator is working. Since it does not have a self-diagnosis system, the VAZ 2114 computer may not generate errors. You will have to check it using a general analysis of engine operation.
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.
Calibrating a new IAC
What should I do if the test reveals that the sensor needs to be replaced? It needs to be calibrated.
- We check the distance from the end of the rod to the mounting plate, it should be no more than 23mm.
- We disconnect the minus from the battery, de-energizing the ECU.
- Install the regulator.
- We connect the battery back.
- Turn on the ignition for 5 seconds without starting the engine. At this time, the IAC calibration occurs.
- Turn off the ignition to complete the calibration.
- We start the engine and observe the idle speed.
Now you know how the idle air regulator works, how to check it and, if necessary, replace it. As you understand, there is nothing complicated about this and all operations are accessible even to a novice car enthusiast.
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
| Manufacturer | Number | Amount, rub. |
| AvtoVAZ | 21120114830081 | 730 |
| KRAFT | KT104900 | 510 |
| MANOVER | MR21121148 | 450 |
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.
What error codes appear when the IAC is faulty?
If the idle air control is faulty, the on-board computer may display the following errors:
- P1509 - IAC control circuit overloaded;
- P1513 - IAC control circuit, short to ground;
- P1514 - IAC control circuit, open or shorted to +12 V.
When deciphering fault codes via the Internet or in the vehicle's operating manual, you may sometimes encounter definitions indicating problems with the operation of the IAC. They often indicate a regulator failure. Errors can be seen not only on the on-board vehicle, but also when diagnosing a car using a scanner. Sometimes they indicate not sensor defects, but contact failure.
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:
- Secure the car with the handbrake.
- Remove the negative terminal from the battery.
- Remove the engine protective screen (for 1.6).
- Loosen the clamps on the crankcase exhaust pipe and the corrugated pipe.
- Disconnect the corrugation from the throttle assembly.
- Remove the upper idle crankcase ventilation pipe.
- Remove the throttle cable.
- Unscrew the 2 nuts of the throttle assembly and remove it from the studs.
- On the left, below, find the location of the IAC.
- Unplug the power plug from the sensor.
- Unscrew the 2 screws of the regulator using a Phillips screwdriver.
- Clean the assembly from carbon deposits and dirt using carburetor cleaner.
- Coat the rubber ring of the regulator with machine oil.
- Install the IAC into the throttle mechanism.
- 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.
Replacing the idle air control valve VAZ 2114 - step-by-step instructions with photos
1. As we wrote above, pxx is located on the throttle body.
Remove the decorative engine cover.
2. Disconnect the tube inserted into the air duct, as shown in the figure.
3. Next, loosen the clamp and remove the air duct from the throttle valve.
4. Carefully remove the throttle cable, as in the photo.
5. Now, you should unscrew the throttle assembly.
The throttle assembly is secured to two 13mm bolts.
6. After unscrewing the throttle, we can easily remove the throttle and install a new one.
Before installing the new px, clean the mounting hole. It is advisable to lubricate the O-ring with oil.
7. After installing the pxx, we reassemble in the reverse order.
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:
| UTRAI starter 4 in 1 air compressor 24000mAh | Idle air control valve for Daewoo | Car Inverter 6000W Peak DC 12V/24V AC 220V |
| Automotive compass AUTOOL X95, horizontal inclinometer | 12V car heater | EVA mats in a VAZ Lada Samara car |
Homemade IAC tester
In some cases, checking the idle speed control with a multimeter is borderline useless. For example, on injection VAZs. In this case, the multimeter data will not be informative, since the main problem is coking of the screw pair. This problem leads to the sensor becoming stuck, causing it to simply not provide a constant flow of air.
Some craftsmen independently manufacture devices for checking IAC in such a situation. For a homemade tester, you need to have a 6V AC phone charger transformer on hand. If you use the controllers alternately, you can check the forward and reverse stroke of the regulator. The working device will illuminate the indicator light with a dim light, and the opposite effect will indicate jamming and the need for repair.
Preparing for replacement: choosing a sensor and the necessary tools
Before you begin replacing the sensor, you need to carry out some preparatory measures. First of all, this is the purchase of a new spare part. You can find quite a lot of sensors on the market that are suitable for the VAZ-2114, but there are two of the most proven and affordable :
Idle speed sensor
- sensor from K3TA – marking: 2112-1148300-04 ;
- and a device from OMEGA - marking: 2112-114830 .
Important! When choosing, pay attention to the needle rod exit indicator; it should not exceed 23 mm.
You will need few tools for replacement. In most cases, it is enough:
- pairs of Phillips screwdrivers of different sizes;
- wrench size “13”;
- any unnecessary rag;
- lubricantsWD-40;
- and cleaner for carburetors or injectors.
Important! Use only clean tools that are in good condition. Otherwise, there is a risk of damaging the edges of the fasteners of some components that are removed during replacement.
