The coolant temperature sensor or DTOZH on a VAZ 2112 car with a 16-valve engine performs the function of monitoring the state of antifreeze in the system. If the controller fails, the driver will receive incorrect data on the temperature status consumables. Read more about device replacement and malfunctions below.

[Hide]

Characteristics of DTOZH

First, let's look at the main characteristics of the regulator, which is often called a fan switch sensor. Let's start with the operating principle.

Principle of operation

The design of the part is based on a thermistor-resistor, which changes the resistance level depending on the temperature conditions. The thermistor itself is installed in a steel case with a thread applied to it. Directly connected to the body is the rear plastic part of the device, which contains the contacts necessary for connecting the power wires. One of these contacts is positive and it comes from the ECU, the second is negative, which is connected to the body.

In order for the engine temperature sensor to operate, it is powered by a voltage of 5 volts. The voltage is supplied from the ECU through a constant resistance resistor. Since the DTOZh thermistor itself has a negative temperature coefficient, as the temperature increases, the resistance parameter on it will begin to fall. In addition, the voltage supplied to it will also decrease. As a result of the decrease, the ECU calculates the temperature power unit, and the corresponding readings are transmitted to the instrument panel. The regulator should turn on when the ignition is turned on.

Where is?

If you are the owner of a VAZ 21124, you will probably be interested in knowing where the coolant temperature regulator is located on a VAZ. On Ladas of the 12th family, the location of this device is quite simple - as can be seen from the photo, it is installed in the metal exhaust line of the cooling system on the cylinder head. The VAZ fan switch located here allows you to accurately determine the temperature of the consumable, since antifreeze passes through this line.

In what cases is it necessary to change?

If the VAZ temperature regulator breaks down, the consumables in the system will exceed the boiling point and, accordingly, the antifreeze will turn into steam. Ultimately, this leads to overheating of the power unit, and the steam itself will be released into the air through various holes in the system.

As you know, antifreeze is always under pressure, so if it begins to act up, the cap expansion tank you need to open it as carefully as possible. Otherwise, the refrigerant that splashes out may cause burns on the skin. In general, the VAZ engine temperature controller is a fairly reliable part that fails relatively infrequently.

But, like any other device, such a regulator has certain defects that lead to its failure:

• the contact on the internal board of the device disappears;
• breakdowns appear in the insulation of the regulator (video author - Vasily Kalugin).

As for the main symptoms of a part failure, its failure can be determined by the following signs:

1. The fan does not turn on. As you know, the fan is activated when the engine heats up, and it can also turn on after the internal combustion engine is turned off. If the fan does not turn on, this may indicate not only a breakdown of the controller, but also oxidation of the power contacts. Therefore, first of all, it is necessary to diagnose the connection of the ventilation device and, if necessary, clean the contacts from oxidation.
2. Another symptom is that the engine stops starting normally, problems especially often appear when cold weather sets in.
3. When driving with a power unit that is not warmed up, the exhaust will be bad.
4. Another sign is the appearance of steam from under the engine, this already indicates its overheating.
5. On vehicle fuel consumption may increase.

As practice shows, when such symptoms appear, replacement of the cooling system controller is usually not required. In fact, the problem is usually a poor connection or damage to the wires, in some cases it may be a refrigerant leak. So first you need to visually diagnose the device for defects or damage.

Replacement instructions

To replace the regulator at home, you do not need any specific tools or skills; everything is quite simple. Z Changes should be made when the car has cooled down to avoid getting burned!

Do it yourself as follows:

1. First, the car's electrical network is de-energized; to do this, simply remove the terminal from the battery by unscrewing the nut securing it with a wrench.
2. It is necessary to drain part of the consumables from the radiator device into a pre-prepared container. The container must be clean, since this antifreeze will be poured back into the system.
3. To easily replace the controller, dismantle the housing air filter. You don’t have to remove it, it will just be easier to replace it this way.
4. After completing these steps, you can dismantle the block with wiring from the controller power supply. Make sure that there is no corrosion on the contacts; if there is rust, it must be removed with an iron brush.
5. Then unscrew the regulator from the installation location; for this, use a 19mm wrench. Install a new sensor; before installation, make sure that there is a metal ring on its thread. In order to securely fix the regulator, it can be placed on a sealant. Further actions Assembly is carried out in reverse order.

Video “Visual instructions for replacing the controller at home”

You can learn more about how the process of replacing the sensor takes place using the example of the domestic “ten” from the video below (the author of the video is the Garage TV KR channel).

Taras Kalenyuk

Reading time: 4 minutes

A A

DTOZH does the job of determining the thermal level of antifreeze, transmitting the collected temperature to the ECU. After data processing, on-board computer regulates following parameters engine operation:

• number of revolutions;
• saturation of the fuel mixture;
• operation of fans.

The temperature sensor on the VAZ 2110 is located in the thermostat, being immersed in antifreeze. Thanks to this, optimal accuracy of the obtained indicators is achieved.

For VAZ 2110″ width=”635″ height=”502″ /> Replacement with VAZ 2110

IN this car There are two temperature detectors. It is worth paying attention to this and, if the need arises, try not to confuse them.

The one located in the thermostat is the coolant temperature sensor.

The second thermal detector can be found in the cylinder head. This is a pointer sensor.

It has slightly different functions than the DTOZH, but in case of any breakdowns related to the engine temperature, you may have to check both detectors.

The cooling system of the VAZ line of cars represents the coordinated work of all its parts:

1. fans;
2. radiators;
3. sensors;
4. antifreeze.

The coolant not only does the job of maintaining the temperature balance of the engine, but also protects its parts in contact with the environment from corrosion, and also protects the system from clogging.

And the temperature detector is designed to monitor the state of this liquid.

The same system is typical for the VAZ 2114 and similar models.

How does a temperature sensor work?

DTOZH is a device with a negative temperature coefficient, in other words, a thermistor. This means that the detector represents the measured thermal data in the form of resistance, which is transmitted to the control unit. The higher the heating of the antifreeze, the lower the reading.

Without changing the topic, it’s worth talking right away about how to check the functionality of the device.

To do this, you should arm yourself with a multimeter and a thermometer that can withstand high temperatures:

• First, you should prepare a container that is filled with coolant. You need to choose a container in which you can heat the liquid;
• the multimeter is switched to the ohmmeter state, a detector is connected to it;
• a sensor connected to a multimeter, as well as a thermometer, is lowered into a container with liquid
• gradual heating of the antifreeze begins;
• the obtained data are compared with the norm and, if they do not match, the device requires replacement (repair of this part is impossible, so its malfunction can only be treated by purchasing a new sensor).

The exact data can be found in the documents for a specific device, but as an example we can say that at a temperature of 30 degrees, the resistance on the multimeter will be more than one and a half thousand Ohms. And as soon as the heating of the antifreeze reaches 100 degrees, the readings will drop to a level of less than two hundred.

In the same way, you can check the new temperature sensor to make sure it is working before installation.

Data different cars may coincide, be it a VAZ 2114 or a VAZ 21093, but different models detectors can give different readings, so it is better to use the standards for this specific brand of device when checking.

How does DTOZH help engine performance?

The collected temperature data is transmitted to the control unit, which then controls the system based on the received data:

The very first thing you should pay attention to is that the engine does not start well. Regardless of the weather and temperature outside, starting it is difficult. Difficulties in stopping the engine, as well as its uncharacteristic operation at idle, should be included in one group of this symptom.

The second sign is excessive consumption of fuel and coolant. The first is due to the fact that in the absence of the need to supply an enriched mixture, it is still saturated. And antifreeze simply boils away when the engine temperature is too high. This is especially dangerous because it can lead to engine failure.

On a VAZ 2110″ width=”659″ height=”446″ /> To replace the temperature sensor, use a 19 key

Another reason to think about the performance of the DTOZh is the uncharacteristic color exhaust gases, which may be a sign that the ignition angle is not working well.

At increased consumption fuel, not only the coolant temperature detector may be faulty, but also other sensors - lambda probe, phase sensor, etc.

Why does the engine temperature sensor break?

In fact, there are not many of them. On VAZ 2114, 2110 or 2107 cars, the causes of breakdown are not much different.

First of all, you should pay attention to the entire cooling system - evaluate the integrity of the wiring, the quality of contacts and terminals, the serviceability of fans, as well as the level and quality of antifreeze.

All these factors can lead to the fact that the sensor fails earlier than the car owner expects (not “if”, but “when”, because any part fails sooner or later, and something as small and actively used is even more so)

Thus, before installing a new analyzer in place of the faulty one, it is worth making sure that the entire system is working normally, so that the installed part does not burn out prematurely because the car owner was too lazy to look for breaks in the wiring.

First you need, of course, to start the engine, and then watch the temperature level scale on the dashboard.

If the arrow goes off scale and the engine is cold, you need to disconnect the contacts from the sensor and see what happens next.

On VAZ 2110″ width=”644″ height=”395″ />

If the readings have changed, then the DTOZH needs to be replaced. If everything remains unchanged, then the breakdown lies in the circuit up to the detector - the integrity of the wiring is compromised, the contacts are faulty, etc.

If the arrow jerks back and forth, you need to check the fuses.

How to replace the engine temperature sensor on a VAZ 2110?

First of all, you need to purchase a device to replace the broken one, observing the labeling. In addition to official devices, there are analogs, but you need to be careful with them so as not to waste money.

Once the sensor is ready, you can start replacing:

• First of all, you need to turn off the engine and cool it;
• next you need to remove the interfering parts (for example, a pipe);
• de-energize the system by removing the negative terminal from the battery;
• drain the antifreeze, since after removing the temperature sensor it may spill out of the opened hole;
• disconnect the block of wires leading to the detector;
• unscrew the device with a key of a suitable size (on the VAZ 2110 it is No. 19, as on the VAZ 2114);
• put a new DTOZH in the vacant place;
• After you have swapped the devices, reassemble the system in the reverse order and start the car to check the proper functioning of the cooling system.

To avoid coolant leakage through the sensor socket, you can use sealant or an O-ring.

Bottom line

What's good domestic auto industry, is that some of the nuances regarding work under the hood are almost the same for the entire model line. Take the same DTOZH. Whether it is a VAZ 2108 or cars of the Samara-2 series (like VAZ 2114 or VAZ 2115), the signs of malfunction, location, replacement details are all the same.

The coolant temperature sensor, or, in short, DTOZH, is a device that determines the temperature of the antifreeze in the cooling system and gives a signal to reduce it by activating the fan.

Its performance is an important aspect of the normal functioning of the cooling system and the entire power unit as a whole, and therefore in this material we will talk about what signs of a DTOZ malfunction help to promptly identify problems in its operation and effectively eliminate them.

DTOZH - what is it in the car?

The coolant temperature sensor in a car is a compact device located in the radiator housing or, often, in the outer part of the power unit housing - the so-called “jacket” of the cooling system.

Purpose

The sensor is designed to determine the temperature of the coolant, which is displayed on the information indicator located in the car’s instrument panel.

The sensor’s function is also to activate the cooling fan, which lowers the antifreeze temperature if it exceeds critical values ​​(more than 80 degrees Celsius). This is done in order to avoid boiling of the antifreeze and, as a result, overheating of the engine.

Video - nuances associated with coolant temperature sensors on the Volkswagen Passat B3:

A similar purpose of the sensor was typical for carburetor engines. Today, with the development injection systems injection, the DTOZH is assigned a significantly larger number of functions. These include:

• increasing engine speed during the warm-up phase to optimize the engine’s output to operating mode;
• opening or closing the exhaust gas recirculation valve;
• setting the ignition timing, etc.

Principle of operation

The functioning of the DTOZH is carried out on the basis physical properties The sensor material changes its own electrical resistance depending on the degree of heating.

Essentially, it consists of two electrically conductive contacts and a cone-shaped working element made of sensitive material. The change in the degree of electrical conductivity is recorded and, thus, the sensor “provides” information about the temperature and the achievement of its critical values.

On modern cars, “responsible” for reading such information is the electronic unit control ECU, which issues control commands to the ignition system, and also analyzes the performance of the sensor itself.

Kinds

Conventionally, two types of DTOZH can be distinguished: mechanical and digital. What are their similarities and differences?

Mechanical

Mechanical DTOZH is a simple unit where the transmission of information about changes in material resistance is carried out, so to speak, in “analog” form - through an electrical signal. Such a sensor is directly connected to the coolant temperature gauge, which is, in fact, a simple ohmmeter with a scale graduated in degrees Celsius.

A relay is connected to the node, which closes when the critical temperature is reached and causes the cooling fan to operate. Such sensors are found on cars with carburetor engines, including all domestic Zhigulis.

Digital

The design of a digital DTOZH is not very different from a mechanical one, but the signal is transmitted via a bus directly to the digital control unit of the ECU.

The built-in processor performs primary analysis of information, displaying temperature data on dashboard, as well as giving commands to the ignition system. In this case, the fan is also turned on via a command from the ECU.

What does it affect?

The main task of the coolant temperature sensor is to turn on the cooling fan. As a result, if it malfunctions, the fan does not operate, and this may result in overheating of the motor or, at a minimum, boiling of antifreeze in the system.

Video - how to check DTOZH with a multimeter:

In addition, on injection engines, a malfunction of the DTOZ leads to the fact that the ECU sets the wrong ignition timing, and the engine begins to operate in unfavorable conditions.

The combination of these factors suggests that timely detection of sensor failure and its replacement is a key element in avoiding a number of problems, and sometimes costly car engine repairs.

The main causes and symptoms of a malfunction of the coolant temperature sensor

As a rule, due to the simplicity of the design, breakdowns of the coolant sensor itself are relatively rare. However, there are a lot of “reasons” for it to start malfunctioning, and these include the following reasons:

1. Low quality antifreeze

If a bad one is used, it is not uncommon for the surface of the sensor to become corroded or covered with crystalline deposits. In this regard, the temperature effect on the sensor changes and, as a result, its readings change, usually towards a lower temperature. This leads to untimely switching on of the cooling fan, as well as a change in the operating mode of the power unit.

2. Poor quality of the sensor itself

Unfortunately, there are a large number of counterfeit spare parts on the market, and DTOZ from a no-name manufacturer does not always meet factory parameters. Also, the sensor may have minor damage, which during operation can contribute to its failure.

3. Antifreeze leaks through threaded connection sensor

And, as a result, a change in its indicators. This phenomenon occurs when the integrity of the thread is violated in cases where the sensor was installed with excessive tightening force or there is wear on the liner gasket.

4. Electrical failure

This factor is the main reason for the failure of the sensor and can be caused by a number of reasons - from a sudden surge in voltage in the on-board electrical system of the car to ordinary corrosion of the contacts. Actually, the contacts should always be checked for oxidation when removing or installing the DTOZH.

5. Thermostat malfunction.

How to check the coolant temperature sensor

If you suspect a malfunction of the DTOZH, it is necessary, first of all, to determine whether the breakdown concerns the sensor itself or whether it is caused by failures in electrical system auto.

To do this, you need to unscrew the sensor and diagnose it. This can be done using a regular household multimeter.

How to check DTOZH with a multimeter

To measure the resistance of the DTOZH at different temperatures on the multimeter, you should turn on the ohmmeter mode with the appropriate measurement limit.

The resistance value must be in a certain range at specific temperatures.

For each model of power unit and brand of car, the resistance of the sensor at different fluid temperatures has its own values ​​(!) and you should familiarize yourself with them in advance in the manual!

To check, the sensor should be removed and immersed in water heated to a certain temperature, connecting a multimeter to the output contacts of the DTOZH. If the sensor resistance does not match the values ​​specified for your vehicle's engine, it should be replaced.

Video - how to check the coolant temperature sensor using a multimeter and an electric kettle:

In addition, measurements can be made directly on the car as the engine warms up at idle speed.

If the sensor is operational, you should look for the cause of the breakdown in the electrician or thermostat. If the DTOZH is faulty, it should be replaced.

Replacement

The procedure for replacing the DTOZH is extremely simple and consists of unscrewing the old sensor and installing a new one, followed by connecting the control terminals to it.

However, there are some nuances. In particular, it makes sense to combine the replacement with replacing the coolant in the car engine. In this case, it is a good idea to treat the mounting socket for the sensor with graphite lubricant, which will protect the thread, ensure easy unscrewing and create an additional layer of sealing.

Video - replacing the coolant temperature sensor on a VAZ 2115:

Also, when replacing the sensor, it is necessary to sand the electrical contacts suitable for it with fine sandpaper. If the DTOZH is working properly, and you do not plan to change it, it makes sense to clean it as a preventative measure, including sanding its contacts to improve electrical conductivity.

Conclusion

As you can see, checking and replacing DTOZH is a fairly simple procedure. It does not require specialized skills and knowledge, as well as special equipment (with the exception of the mentioned multimeter).

remember, that timely replacement A faulty coolant temperature sensor will help you avoid a number of problems, including possible overheating of your car’s power unit.

Video - how to check the coolant temperature gauge on a Chevrolet Lacetti:

May be of interest:

Scanner for self-diagnosis car

How to quickly get rid of scratches on a car body

How to check a used car before buying

How to apply for an MTPL policy online in 7 minutes

Similar articles

Comments on the article:

Ivan

Finding out whether the DTOZH works is quite easy, provided that you have a car with an injector. During a cold start, the car will start and run well, but as soon as the engine warms up, the engine will start to run unevenly, and it will be almost impossible to start the car with a hot engine due to the over-rich mixture.

Anton

My Passat has 2 sensors. One is for the indicator on the dashboard - it does not affect the operation of the engine, and the other gives a signal to the ECU - this is the main one.

Karina

Since I am just a novice driver, I learned a lot, it is actually very easy to check the coolant temperature sensor.

Maksim

My Corolla Fielder had a malfunction of the coolant temperature sensor, the computer began to adjust the engine operation to its readings, and problems began. The article describes well how to check it! It helped!

Valery

I didn’t know that it was so easy to check the sensor, so I went to check it, since I had a multimeter available. I unscrewed it, measured it, calmed down - it was working.

Peter

If the coolant temperature sensor is damaged, you need to react immediately. After all, roughly speaking, it is he who gives the signal to start the cooling fan. And if the sensor is faulty, gasoline consumption will increase. In this case, I check all the electrical wiring of the car and if I am sure that the cause is the sensor, I replace it. Replacing it with your own hands is as easy as shelling pears; you only need to see it once or try it yourself.
You need to unscrew the old sensor, treat the socket with graphite grease and put a new one in its place; do not forget to connect the control terminals too. The main thing is that it is airtight.

Andrey

The first thing you need to know is that there is more than one temperature sensor in a car. There are at least two of them, and in some models up to 4-5. The second is where they are located and specifically what each of them is responsible for. The classic scheme is two sensors, one goes to the dial gauge of the panel in the cabin (or in digital form), and the second goes to the cooling fan(s). Accordingly, their operating principles are different, they need to be checked in different ways. The first one changes its resistance in a linear relationship with the coolant temperature (at the same time we see a change in the deflection of the panel arrow), and the second one works on the ON/OFF principle when a certain coolant temperature is reached (turns the fans on and off accordingly).

Alexey Z.

In general, it’s difficult to imagine how bad antifreeze or antifreeze can damage a temperature sensor; I haven’t seen anything like it in twenty years. The sensor body is usually made of copper or brass alloy, which practically does not react with the coolant. But failure due to poor quality workmanship is not a rare occurrence. If those sensors that come from the factory on a car last for several decades, then those that are supplied as spare parts very often do not last even three. It’s a paradox, but both of them were produced at the same factory. For this reason, the buyer often prefers to take a disassembled sensor rather than buy a new one.

Artyom

The liquid cooling sensor turns on the fan at the right moment, and therefore if it is faulty, it is fraught with serious malfunctions and damage. There can be several reasons for a breakdown, such as low-quality antifreeze and a cheap sensor. Sometimes the sensor may be fine; in some cases, you need to check the wiring and contacts. You need to unscrew the sensor and check it by immersing it in water and taking a multimeter. It’s not all that complicated, you just need to replace it once in the presence of a knowledgeable person or find information on the Internet and you’ll do it yourself. If the sensor is faulty, you need to replace it, just remember to clean the contacts and terminals.

San Sanych

In fact, multimeters like D830/DT830 (thousands of them) allow you to determine temperature with an acceptable error. As control points for testing, you can only use water ice that has begun to melt (something around 0 degrees is guaranteed) and boiling ethyl alcohol (~78.37 degrees). Boiled alcohol is also convenient because it is the very critical point at which the coolant temperature sensor must operate stably so that the antifreeze does not boil away. And as has already been correctly noted in the comments, if the sensor at the indicated temperatures shows resistance within acceptable limits (this is discussed in detail in the second video), then the fault lies either in poor-quality wiring or in poor-quality antifreeze.

Maksim

I got used to changing faulty sensors without draining the coolant. To do this, it must first be “torn off”; sometimes, after ten years, the thread becomes so stuck that it is better to use a head or, at worst, a spanner. Then carefully turn it out with three fingers, monitoring the amount of liquid that flows out. Then sharply remove the sensor and plug the hole with your finger. Take a breath, take the previously prepared new DTOZH with your free hand, bring it to the hole that you hold with your finger and vigorously (sharply) plug the hole with it, removing your finger. Next, screw it in along the thread. Liquid loss is 200 - 300 grams, and time savings is several hours! Sometimes you don’t even have to top up, the level doesn’t drop to the minimum.

Sergey

When checking DTOZH they are also taken into account specifications cars according to the corresponding tables to various resistance drops, but there are no standardized readings. If there are slight deviations from the indicators, the sensor should not be changed; it is necessary to find another reason for engine malfunctions. Sensors from different manufacturers always give different readings at the same fluid temperatures. Before troubleshooting problems with replacing the sensor, you need to select suitable option for your car. If you buy on the market, be sure to check the certificate. To exclude fakes, take a photograph of this document for further presentation to the relevant authorities. Basically, with such actions, the seller will not sell you a fake.

Macarius

When the latest Volga car models began to be equipped with liquid cooling fans powered by electricity, the operation of such cars arose with the problem of rapid engine overheating when the car was operating in the rhythm of city traffic. Either the sensor was set up so unreasonably at the factory, or because the engines became more high-speed, and their operation was allowed not at 80 degrees Celsius as before, but at 90. The drivers came up with manual forced activation of the fan, which was carried out directly from the driver’s cabin . The driver was ahead of the sensor command to turn on, and thus improved the stability of the car in traffic jams.

Nikolai

My native served for 7 years. Last year I had to replace it. I'm talking about a sensor that turns on an additional fan (Chevrolet Niva). The first time I didn’t understand what happened at all. It's summer, it's hot, the temperature rises quickly and the fan turns on often, especially when driving in the city. One day I noticed that the fans in a pair were working too fast. In the morning, with a cold engine, the second one turned on in just a couple of minutes. The problem was with the relay, I replaced it, but it didn’t solve the problem. I dug into the book, found this sensor near the pump, replaced it and forgot about the problem.

Oleg

Failure of the coolant temperature sensor can lead to engine failure and very large financial losses compared to its cost. Therefore, if you have doubts about its serviceability, it is better to protect yourself. I checked my sensor without removing it from the car. I just started the cold engine and connected a multimeter to its terminals. I changed it by first draining the coolant (then I replaced it). But I don’t agree about using a multimeter as a temperature meter: there is no accuracy, it all depends on the purity of the liquid. And also, in order not to end up with an overheated engine if the temperature sensor fails, I installed a fan switch in the interior as a safety net.

Dmitriy

In a car, the sensor is always next to the thermostat for the greatest measurement accuracy. When the sensor fails, and the instruments in the car ever break down, the following problems may arise: fuel consumption will increase, CO2 emissions will increase, the engine may stall, the car will warm up slowly, and the engine may overheat.
The operation of the sensor may be affected by old wiring, corrosion, but the sensor may be working properly. Therefore, it is better not to huddle, but to buy a new sensor and immediately cast aside doubts about the causes of the problems.
But it is best not to skimp and purchase a new sensor that will ensure a safe and enjoyable driving experience without any problems.
If there are signs of a malfunction of the coolant temperature sensor, you can immediately replace it. If you wish, you can diagnose it, but first make sure the wiring is in good condition. The sensor should be supplied with 5 volts, which can be checked with the engine running. If there is 5 volts, then check the sensor.
If desired, you can diagnose it to make sure that the sensor is the source of the problems. You can check it using an electric kettle. We measure the temperature +10, +15, +20 and record the sensor resistance.
If the readings differ from the data for the sensor (can be found on the Internet), then the coolant temperature sensor is faulty and needs to be replaced. Less precise, but more simple, without a thermometer, and by boiling water - it boils at 100 degrees. This will be the checkpoint. Boiling resistance is about 210-190 Ohms.

Oleg

When the coolant temperature sensor fails, it gives rise to a number of problems, the main and most dangerous of which are the following:
The engine temperature goes beyond the permissible limits;
Violation of engine stability;
Increased fuel consumption;
Drop in speed and spontaneous engine stop.
If there is any suspicion of unstable work temperature sensor, first you need to check the presence of coolant and its level.
Next, we check the quality of the contacts for oxidation.
If everything said above is in order, then you need to check the sensor itself, for which it must be removed.
We take the sensor and lower it into a glass of boiling water and measure its resistance; specific data can be found on the Internet for each sensor. If the data matches, then the sensor is normal. Otherwise, we change the sensor.

Nikolai

The coolant temperature sensor was changed a week ago. I was standing in a traffic jam in Moscow and purely by chance I looked at the instrument panel (I have a Chevy Niva) and was stunned. The device shows about 110 degrees and silence - the fans are not working. I turned on my emergency lights and pulled over to the side of the road. At first I thought it was the fan motor, I applied voltage directly to the motor - it works. I connected the fan motor to the battery and while driving around Moscow it was constantly threshing. I went to M2 and disconnected the fan. Further to the house. In the garage I removed the temperature sensor without checking it and installed a new one. I started the engine and waited for it to warm up - everything worked.

Ivanovich

The coolant heating sensor is a very important device for normal engine operation. It protects the engine from overheating by turning the cooling fan on and off. In my practice, I have had to deal with the problem of its malfunction several times. In our domestic cars, With mechanical system ignition, analog sensors were used. And if such a sensor suddenly stopped working, it would not turn on the fan at the right moment and the water in the radiator would boil. It is impossible to drive in such a situation, and in order to understand the cause of the breakdown, we first of all checked the proper operation of the fan electric motor and connected its terminals to the power source, bypassing the sensor. If the engine was running, the reason it did not turn on could only be a sensor failure. The sensor needed to be changed, and in order to get to a car service center or garage, they practiced turning on the fan directly, and drove with the fan constantly running. In modern injection cars, the operating principle of the sensor itself is the same, only the fan operation is controlled through the electronic ignition control unit.

ua9ukh

When checking the temperature sensor with a multimeter, the resistance will be normal and when heated at hot water everything will be fine in the thermostat, the temperature readings will malfunction, the temperature readings will fluctuate by one or two degrees not constantly and the engine will fluctuate from hot to cold when the temperature jumps by 10 or 20 degrees, the fan will turn on and there will be an error p1336 misfire in all cylinders

Cars are equipped with many sensors that monitor the condition of all automotive components. One of the most important sensors is the temperature sensor located in the engine compartment.
On a VAZ 2110, replacing the temperature sensor is a responsible process. Replacing the temperature sensor of a VAZ 2110 in this article is done entirely with your own hands.

What is this device?

Despite its importance, it is relatively simple, it monitors the condition of the coolant in the cylinder block jacket. It reports changes in temperature, transmitting this information to the electronic control unit.
The device is a thermistor, whose electrical resistance decreases as the temperature increases.
The temperature sensor readings affect many engine systems and engine performance. Therefore, it is necessary to constantly monitor the health of the sensor and, if any faults are detected, replace it immediately.
A faulty sensor distorts the information supplied to the electronic control unit, which can lead to big troubles. There may be problems with the car's controllability when the engine is cold, emissions, fuel consumption may increase or the composition of exhaust gases may deteriorate.

Note. Often the sensor is replaced only when it breaks. But it is recommended to change it in advance, for example, when repairing or replacing an engine, because the sensor may wear out and the readings may be inaccurate.

DTOZH, as they are also called for short temperature sensor coolant is a device whose readings affect the operation of the engine itself. This should not be forgotten.
A small but remote device closely monitors the car’s engine systems, acting as a kind of watchman.

Replacement process

To check and replace the temperature device, you will need the following tools and materials:

• Socket wrench set to “19”;
• Sealant;
• Coolant;
• Copper washer.

Note. The temperature sensor is located in the VAZ 2110, often in intake manifold near the thermostat housing, rarely in the cylinder head.
It is installed so that the tip comes into contact with the coolant. Only in such cases is his signal correct.
If the coolant level is low, the sensor readings may be incorrect.

When is replacement needed?

If the resistance of the sensor is high on a cold engine and no electric current passes through the indicator, its needle is located at a low value. In cases where the temperature gauge does not indicate the engine temperature, then, first of all, you need to check the electrical circuits of the sensor.
You should also check the current supply to the electrical circuit. If the indicator arrow jerks erratically, inaccurate voltage supply or unstabilized voltage may be received.
This requires replacement of the stabilizer.
If you still suspect that the temperature indicator is faulty, then before replacing it you should check its functionality:

• if the arrow points low temperature motor, then you need to disconnect the electrical connector from the temperature sensor and connect it to ground;
• if the arrow deviates when the ignition is on, it is faulty and needs to be replaced;
• if the needle does not move, it is necessary to remove the instrument cluster and check the electrical circuit between the indicator and the sensor and the voltage supply (if the electrical circuit is in good condition, it means that the temperature indicator is faulty and needs to be replaced).

Note. It should be borne in mind that quite often problems with the device arise due to poor wiring or loose, rusty connectors.

• in cases where the temperature gauge constantly shows a high temperature, you need to disconnect the electrical connector from the device (if the gauge needle moves on the cold temperature scale when the ignition is on, this indicates a malfunction of the temperature sensor and it needs to be replaced).

The breakdown of this device is sometimes noticeable visually - this is a liquid leak, severe corrosion of the clamps or cracks on it.

Note. You should also check the condition of the coolant. If it has been used for more than 3 years (for a regular one) and more than 5 years (for a durable one), then it needs to be replaced. It is replaced when obvious signs its contamination.

Replacement directly

Replacement of DTOZH is carried out in the following order:

• First, turn off the ignition and from the terminal battery the wire is disconnected;
• The coolant is drained from the radiator;

Note. It is not necessary to drain the coolant completely; you can open the drain valve and drain such a volume of liquid so that its level is below the sensor.

• To make it more convenient to work, you can remove the air filter;
• The block with wires is disconnected from the temperature sensor by squeezing the plastic clip;
• The DTOZH is unscrewed from the cooling system pipe using a key set to “19” (in this case, the sensor is removed along with the copper sealing washer).

Note. Care must be taken when working with the sensor.
Damage to the device may interfere with the normal operation of the engine control system. You need to know that it cannot be removed until the engine has cooled down.

If replacement is necessary, install the new sensor in the reverse order of removal.

• Before screwing in the temperature sensor, apply a thin layer of sealant to its threads;
• The sensor is then screwed into place and the electrical connector is connected to it;
• Coolant is poured or added to the cooling system;
• After this, the engine is started and the operation of the temperature indicator sensor is checked.

Finally, the cooling system is checked for leaks. If necessary, the sensor is wrapped tighter into the thermostat housing.
It is also necessary to check the cooling system for the presence of air in it, which, when entering the thermostat, can cause engine overheating, thereby changing the readings of the temperature sensor.

Note. In cases where the leak cannot be eliminated, the sensor must be reinstalled. This will require applying more heat-resistant sealant to the threaded part or replacing the copper washer.

It is recommended to watch this video before carrying out work.

In addition, it is recommended to use photographic materials more often, where everything is clearly visible.
With your own hands, as can be seen from the article, you can do a lot, including repairing your car. If you do everything as required by the instructions, then no problems will arise, even for a beginner.
Plus you can save a lot of money family budget, because the price for services of this type in our country is not cheap.

To maintain optimal temperature conditions of the car engine, a cooling system is designed. Its main elements are channels for antifreeze in the cylinder block, pipes, a thermostat, a radiator, and the electrical part includes a VAZ 2110 fan switch sensor, a temperature sensor and an electric motor with an impeller for. Late detection of cooling system defects can lead to engine overheating and costly repairs.

Fan switch sensor LS 0108 (TM-108)

Connection schemes

In injection and carburetor engines VAZ 2110 bimetallic temperature sensor TM-108 is used in different ways to control turning the fan motor on and off.

For carburetor engines it is located on the radiator on the left in the direction of travel. When the threaded part located directly in the coolant is heated, the bimetallic plate bends and closes the contacts. The voltage from the battery is supplied through a fuse to one contact of the electric motor, the second, when the sensor is triggered, is connected to the housing, setting the impeller in motion.

Fan switching sensor (carburetor VAZ 2110)

For VAZ 2110 and TM-108 injectors, it is located near the thermostat, the signal is sent to the electronic control unit (ECU). The control signal from the ECU is sent to the cooling system fan relay, which, similar to the sensor of a carburetor engine, controls the electric motor.

Injection fan switch sensor

All engines have another device in the cylinder block, the signal of which is used to indicate the coolant temperature on the panel in the cabin.

Before you practice self-repair fan activation sensor, it is recommended to understand in detail the design of the cooling system:

The fan does not turn on

There may be several reasons for this:

• Fuse. IN mounting block fuse F7, rated 20 amperes, may be faulty - it is responsible for powering the electric fan and sound signal circuits;
• Thermostat. The liquid circulates only in a small circle, the radiator and sensor do not heat up, and accordingly, the fan does not turn on. You can check by simply probing the pipes; those connecting to the radiator should begin to warm up after opening the thermostat;
• Sensor. For a VAZ 2110 with a carburetor, the contacts are closed for testing; if the device malfunctions, the electric fan will turn on. The connector of the injection motor must be disconnected; with the remaining elements working, the ECU will detect a break in the circuit and issue a constant alarm signal to the relay, which will forcibly turn on the electric motor for cooling;
• Cooling system fan relay for VAZ 2110 injection engines. The sensor is turned off and the power contacts on the relay located in the additional fuse box are closed. If everything works, then we check the control winding: on one contact there is always a positive from the main relay, connecting the second to the body, we try to hear the operation click. But it’s better to simply replace the relay for testing, temporarily, with a known good one;
• Electric motor. During testing, the connector is disconnected; to force the impeller to turn on, voltage is supplied directly from the battery.

If all the elements are working properly, then you need to look for a break in the wires, “ringing” them one by one. Poor contact of the relay and sensor connection wire terminals with the car body is also possible. The worst case scenario would be an ECU failure, in which case the signal from “leg” 46 usually “floats” and does not reach the values ​​of +12 volts (off) and 0 (on).

The fan runs constantly

This is a rarer defect and occurs in the following cases:

• The sensor contacts do not open, the “Check Engine” lamp is on, carburetor VAZ 2110 when the connector is disconnected, the fan turns off;
• The wires to the device are broken (only at the injector);
• The relay is stuck in the closed state.

To eliminate the malfunction, it is necessary to replace the failed element.

Checking at home

Sometimes the electric motor turns on too late, when the antifreeze temperature is already high. This may be caused by a malfunction of the valve in the radiator cap or abnormal parameters of the switch on sensor. You can check the device’s response temperature at home using a multimeter and thermometer.

After disconnecting the electrical connector, the sensor is unscrewed with a key. To avoid burns, remove the device only from a cold engine, after draining the antifreeze. When reinstalling, it is advisable to use a new sealing copper washer and not apply too much force when tightening.

The intricacies of replacing antifreeze are studied in detail in this article:

The switching temperature is engraved on the end; it can be from 92 to 95 degrees. To check, you need to connect the multimeter in resistance measurement mode and immerse the threaded part in a container of water.

While heating the water and monitoring the readings of the multimeter, we use a thermometer to record the moment it turns on, and when it cools down, the temperature it turns off. Standardly, these are 92 and 87 degrees; with significant deviations, late operation is especially critical, the device requires replacement.

To improve cooling, it is possible to install a double fan from Niva. There are two modifications for placement: after the radiator or in front of it.

Nivovsky injection radiator 21214-1300024-43 (placed in front of the radiator)

On the VAZ 2110, any of the options can be installed with minimal modifications to the fasteners on site. When electric motors are connected in parallel, the current consumption increases to 40 amperes, which requires replacement of the wiring.

Nivovsky suction radiator (placed after the radiator)

Monitor the engine temperature. If you notice overheating too late, then in addition to boiling of the antifreeze and a forced stop, more serious consequences are possible: deformation of the cylinder head, jamming camshaft. If there are defects in the operation of the cooling system fan of the VAZ 2110, the faults can be diagnosed independently by checking the thermostat, electric motor, relay, and switch sensor.