VAZ-2114, lambda probe: signs of sensor failure and replacement

To ensure the stable operation of the engine of a modern car, a variety of sensors are used to collect information about the operation of a particular system. Based on 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.

, рассмотрим его конструкцию и принцип действия. In this article we will talk about what the oxygen sensor (lambda probe) VAZ-2114 is , consider its design and the principle of operation. In addition, we will try to understand the failures of this element and the methods for their elimination.

What is an oxygen sensor

The oxygen sensor is an electromechanical device designed to determine the quantitative oxygen content of 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 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 about the oxygen content in the exhausts, increases or decreases the amount of air to form the mixture.

Where is the oxygen sensor

может располагаться в разных местах, в зависимости от модификации двигателя. In cars VAZ-2114 the lambda probe can be located in different places, depending on the engine modification. In the "fourteenth", equipped with half-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. расположен гораздо удобней. In the 1.6-liter VAZ-2114 lambda probe is 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

имеет достаточно простую конструкцию. The VAZ-2114 lambda probe has a fairly simple design. It is based on a ceramic element with two electrodes. They are usually coated with zirconia. One of the electrodes is in contact with the 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 potential difference arising 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 light illuminates 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 dialing speed;
• Increase in fuel consumption;
• Excess of level of toxic substances in exhaust gases (determined by metering at a specialized station).

What can tell the electronic control unit

If the warning light on the dashboard indicates a fault in the engine, and its combustion is accompanied by the above problems, it is advisable 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.

, вышедший из строя, может заявлять о своей неисправности следующими ошибками: At cars VAZ-2114 the lambda-probe which has failed, can declare the malfunction by 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.

могут быть: The cause of malfunction of the Lambda probe VAZ-2114 can be:

• Overheating of the working element;
• Violation of the tightness of the connection between the sensor and the body of the exhaust manifold;
• Clogged contacts of the device due to the use of poor-quality fuel, or oil (coolant) getting into gasoline.

Procedure for problems with a lambda probe

Having discovered signs of failure of the oxygen sensor, 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 Samar models of the fourteenth model with 1.5-liter engines, Bosch sensors were installed. 0 258 005 133. This lambda probe ensured the operation of the power unit in accordance with the requirements of the Euro-2 standards.

Since 2004, the VAZ-2114 engines have been equipped 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 with our own hands

на работоспособность? How to check the lambda probe on VAZ-2114 for performance? Complete diagnostics of the device can be carried out 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 "minus" 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 voltage of the battery. If it is smaller, then a breakage is possible in the sensor circuit.

If the voltage is ok, check the sensitivity of the probe's working element. To do this, connect a "minus" dipstick of the voltmeter to the "C" output of the sensor, and "plus" to the "A" terminal. 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 "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 begin with, the sensor must be unscrewed from the collector or the receiver tube. 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 anti-rust liquid (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 located 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 sawing its case. As practice shows, after such a procedure, its working capacity is no longer returned.

If you decide to replace the lambda probe, buy a new device in the car dealer that corresponds to 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 engine to its former performance 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 any errors in the sensor's operation.

The first way is mechanical. To implement it, a special spacer (bushing) is screwed in 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 lies in the fact that in the sensor circuit to establish 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 wires. 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 fuel 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.