VAZ-2114, lambda probe: signs of sensor failure and replacement
To ensure stable operation of the engineModern car uses a variety of different sensors that collect information about the operation of a particular system. On the basis of their data, the electronic control unit adjusts the quality of the fuel mixture, regulates its quantity for entering the combustion chambers, determines the required ignition timing, turns on and off various additional mechanisms.
In this article we will talk about what constitutes oxygensensor (lambda probe) VAZ-2114, consider its construction and the principle of operation. In addition, we will try to understand the failures of this element and the methods for eliminating them.
What is an oxygen sensor
The oxygen sensor is an electromechanicaldevice designed to determine the quantitative oxygen content in the exhaust gases. Its application is mandatory for all cars with a class of environmental friendliness above the "Euro-2".
Why is it needed? The matter is that modern ecological norms demand from the car of the minimum maintenance of harmful connections in exhausts. To achieve their reduction is possible only by forming an ideal (stoichiometric) fuel mixture. It is for these purposes and serves as an oxygen sensor, or, as it is also called, a lambda probe. The electronic control unit, having received information on the oxygen content in the exhausts, increases or decreases the amount of air to form the mixture.
Where is the oxygen sensor
In carsVAZ-2114 lambda probecan be located in different places, independing on the engine modification. In the "fourteenth" equipped with 1.5-liter power units, it is on top of the intake pipe. You can get to it only from the bottom, driving the car to a pit or trestle. In the 1.6-literVAZ-2114 lambda probeis much more convenient. It is screwed into the upper part of the exhaust manifold housing. You will immediately see it by lifting the hood.
How the oxygen sensor is arranged
HaveVAZ-2114 lambda probehas a rather simple construction. It is based on a ceramic element with two electrodes. They are usually coated with zirconia. One of the electrodes is in contact with air (taken out of the exhaust communications), and the second - with the exhaust gases.
The principle of operation of the device is based on the differencepotentials that arise between the contacts of the device during engine operation. The electronic control unit sends an electrical impulse to the sensor and analyzes its changes. Based on the increase or decrease of the voltage at the probe contacts, the computer "makes a conclusion" about the amount of oxygen in the exhausts.
Lambda probe: signs of malfunction (VAZ-2114)
The failure of the oxygen sensor "fourteenth", usually accompanied by the following symptoms:
- the "CHECK" warning lamp lights up on the instrument panel warning the driver of an error;
- the engine running at idle turns is unstable (the revolutions swim, the engine periodically stalls);
- a noticeable reduction in power and traction characteristics of the power unit;
- the car "jerks" when speed dials;
- increase in fuel consumption;
- Exceeding the level of toxic substances in exhaust gases (determined by metering at a specialized station).
What can tell the electronic control unit
If the alarm panel lights upa lamp warning about errors in the engine, and its combustion is accompanied by the above problems, it is desirable to test the controller. Today it can be done, both at the service station, and at home. Of course, if you have a special tester and a laptop (tablet, smartphone) with the appropriate software. When connected, this unit will give you codes of possible problems.
The carsVAZ-2114 lambda probe, which is out of order, can report its malfunction with the following errors:
- P0130 - invalid sensor signal;
- P0131 - excessive excess of oxygen level in exhaust gases;
- P0132 - too low oxygen content;
- P0133 - weak or slow sensor signal;
- P0134 - no sensor signal.
What can happen with a lambda probe
The resource of the lambda probe for the "fourteenth"declared by the manufacturer, is 80 thousand km. But this does not mean that it can not fail much earlier or serve twice as long.
The reasonfaulty lambda probe VAZ-2114can be:
- overheating of the working element;
- violation of the tightness of the sensor connection to the exhaust manifold housing;
- clogged contacts of the device due to the use of poor-quality fuel, or oil (coolant) getting into gasoline.
Procedure for problems with lambda probe
Having found signs of failure of oxygensensor, do not rush to run to the store for a new device. Replacing the lambda probe VAZ-2114 is not such a cheap pleasure. The fact is that this sensor costs about 2,5 thousand rubles. Therefore, first you need:
- visually inspect the lambda probe;
- to establish its modification (in case of acquiring a new and subsequent replacement);
- check the operation of the probe.
Which lambda probe on VAZ-2114
On the first models "Samar" of the fourteenth model withpolutoralitrovymi engines were installed sensors of the company "Bosch" 0 258 005 133. This lambda probe provided the power unit in accordance with the requirements of the "Euro-2".
Since 2004, the VAZ-2114 engines of steelequipped with sensors "Bosch" 0 258 006 537. They differ from the previous modification by the presence of a heating element. It is noteworthy that all Bosch oxygen sensors for the "fourteenth" are interchangeable.
We check the performance of the oxygen sensor by our own hands
How to check the lambda probe on VAZ-2114on working capacity? Complete diagnostics of the device can be done only with the help of an oscilloscope. But to determine whether it is a worker or not, it is possible without complicated electronics. This requires only a voltmeter. Connect its "negative" probe to the mass, and "plus" to the "B" terminal in the sensor connector, without disconnecting it from the on-board network. Turn on the ignition and look at the voltmeter. The voltage across the terminals of the device must match the battery voltage. If it is smaller, it means that there is a break in the sensor circuit.
If the voltage is OK, check andsensitivity of the working element of the probe. To do this, connect the "minus" probe of the voltmeter to the "C" of the sensor, and the "plus" - to the terminal "A". The voltage should be within 0.45 V. If this value is exceeded by more than 0.02 V, the sensor should be replaced.
Repair or replacement
Having determined that the lambda probe is "fourteenth"is defective, you can either try to repair it, or simply replace it. Restoring the sensor is to clean its contacts from the carbon deposits. It can cause the device to stop functioning normally.
To start, the sensor must be unscrewed from thecollector or intake pipe. It is not always easy to do this. The fact is that its body very often adheres to the specified elements of the exhaust system. In this case, the liquid against rust (WD-40 or similar) can help. Treat the joint with such a liquid and wait half an hour.
When the sensor is unscrewed, pay attention to its housing. It is not foldable. Contacts, which we have to clean, are behind the slots of the case in its lower part.
Important: do not clean the contacts mechanically (with a knife, sandpaper, nail file, etc.)! So you just aggravate the situation and permanently disable the sensor.
Clean contacts only with chemicals. For example, orthophosphoric acid. Just put the bottom of the probe in the acid for half an hour, and then dry it on the gas burner.
It is not necessary to disassemble the sensor by cutting its housing. As practice shows, after such a procedure, its working capacity is no longer returned.
If you decide to replace the lambda probe, buy inauto store a new device that meets the specification, and install it in place of the old one. After switching on the ignition, start the engine, warm it up and check if the CHECK warning light is on.
Methods of cheating the electronic control unit
There are three other ways to return the enginethe former working capacity without buying a new oxygen sensor. Without a doubt, they were invented by our craftsmen. And they consist in the fact that it is necessary to mislead the electronic control unit so that it does not notice the errors in the sensor operation.
The first method is mechanical. To implement it, a special spacer (bushing) is screwed between the lambda probe and the hull of the collector (intake pipe). Its use allows remote sensor contacts from exhaust gases. Thus, the amount of oxygen between them is artificially increased, and the electronic control unit "remains satisfied" with the result.
It is worth such a deception lambda probe VAZ 2114 about 500 rubles. And if you have a lathe, you can make it yourself.
The next way to cheat the computer is electronic. Its essence is to install a primitive converter consisting of a single resistor (1 MΩ) soldered into the break of the blue wire of the connector and one capacitor (1 μF) connected between the blue and white wire to the sensor circuit. As a result of this simple deception, the electronic control unit will constantly receive the signal of the desired voltage, and perceive the work of the lambda probe as proper.
Alternatively, you can still reflash the controller by changing its software. But to entrust such manipulations with the "brain" of the engine is better than specialists.
How to extend the life of a lambda probe
To keep the oxygen sensor as long as possible, do not disregard the following tips:
- use only high-quality fuel;
- Do not allow oil and other process fluids to get into the fuel;
- Keep track of the engine operating temperature, do not allow it to overheat;
- carry out diagnostics of the oxygen sensor in accordance with the schedule of scheduled works provided by the manufacturer;
- When identifying signs that indicate problems with the lambda probe, do not pull with the diagnosis.