Coolant temperature sensor VAZ 2112-16 valves, replacement

The temperature sensor of a VAZ-2112 car is one of the important engine parts. The purpose of the controller is to warn the driver in time about the threat of antifreeze boiling and turn on the radiator fan. At the same time, the coolant temperature sensor itself may break. You need to know how to check its functionality, and if it fails, replace the part with a new device.

Cooling system controllers:

What functions does the sensor perform?

This device performs a lot of tasks. Based on its readings, the fuel mixture is prepared and the ignition timing is changed. The element also gives commands to turn on the fan in case of overheating.

Enrichment of the mixture is always associated with increased temperatures in the power plant. The lower the engine temperature, the richer the mixture needs to be fed into it. Any electronic control unit works on this principle. And the domestic top ten is no exception.

Main set of sensors for 16-valve VAZ-2112 engines

The ECU must control many parameters at once

The most important information will be the position of the crankshaft. You can turn off all sensors except the DPKV, and this will not lead to the engine stopping

Sensors connected to the ECU

Let's list all the elements one by one:

15 – DTOZH. A resistor screwed into the thermostat housing. The temperature of the antifreeze is determined;
17 – DPRV, also known as DF (phase sensor). The operating principle is the Hall effect. The position of the camshaft is controlled. Check it out here.;
20 – TPS. Resistor fixed to the throttle assembly 19. The angle of deflection of the throttle valve is measured;
21 – Mass air flow sensor. Sensor connected to the filter housing. Controls air flow; the main signs of its malfunction are discussed here;
22 – IAC. Not a sensor, but a regulator (electromagnet). Used in idle mode. About its testing and diagnostics here. About replacing the IAC here.;
24 – lambda probe or oxygen sensor (see above);
25 – speed sensor. Fixed in the gearbox slot. Operating principle – Hall effect;
26 – DPKV. Electromagnetic sensor. The position of the crankshaft is controlled;
27 – DD (knock sensor). A piezoelectric element mounted on the outer wall of the cylinder block.

Let's take a look at how all the elements look in real life. Shown are pictures of VAZ-2112 sensors (16-valve internal combustion engine).

Each element will be easy to find under the hood

Everything said above is true for two engines at once - for units 21124 and 21120 (1.6 and 1.5 l).

Where is which sensor located - engine compartment diagram

Let's look at another picture.

Engine compartment and engine 21124

It is important to understand where the following elements are located:

DPKV;
Lambda probe;
Speed sensor;
RXX;
TPDZ;
DMRV;
DTOZH.

The location of the phase sensor is indicated in the previous chapter.

Sensor device

At the dawn of the automotive industry, simple thermal relays were used as coolant temperature sensors (hereinafter referred to as coolant temperature sensors) - they were installed on most internal combustion engines. These sensors can now be found on K-Jetronic single-injection systems and the like. These were used on old Mercedes from the 80s and 90s. How it works? When the relay contact is in the open position, the engine warms up. When the contact is closed, the electronic control unit understands that the engine has heated up to operating temperatures. The concentration and composition of the mixture changes.

Nowadays, thermistors are used as DTOZ. These are resistors that change resistance depending on the temperature of the environment. In the VAZ-2110 car, the coolant temperature sensor is of this type. Heating is monitored continuously, without interruption. Thermistors for these sensors are made from nickel oxide or cobalt oxide. These alloys have a peculiarity: as the temperature rises, the number of free electrons in them increases, due to which the resistance decreases.

The thermistor located inside the DTOZH has a negative temperature coefficient. The maximum resistance level is achieved when the engine is cold. A voltage of +5 V comes to the temperature sensor and as the engine heats up, it decreases. The ECU records the slightest changes in voltage, and thus the coolant temperature is determined.

Sensors with positive temperature coefficients can be installed on engines from Renault and some other power units. They are arranged similarly. However, as the antifreeze temperature increases, the resistance on the sensor does not fall, but increases.

We check the mass air flow sensor on a VAZ-2110 with a multimeter

The sensor block, the first wire may not be there - this is normal.

To do this, we need to understand the pinout and the sensor connection diagram. As you can see, the block has only five wires:

+ 12 Volt.
+ 5 Volts.
Total ground (green wire).
Air temperature output signal.
Air flow signal output (yellow wire).

Electrical diagram for connecting the mass air flow sensor.

The pinout may differ in different firmware versions and on different sensors. Everything is clear with the first two contacts - take a multimeter and check the presence of voltage when the ignition is on. If there is no signal, we look for the cause either in broken wires or in poor contact. Now we check the main indicator - the accuracy and magnitude of the air flow signal. By the way, this can be checked without a multimeter, using the on-board computer, if one is installed:

We go to the menu, look for sensor parameters.
Find the voltage Udmrv.
The rating for all of the above modifications is from 0.996 to 1.01 V.

The platinum thread gets tired over time and distorts the impulse upward. A change of even one hundredth of a Volt is unacceptable. If the computer is not installed, we use a multimeter. We check the voltage between 3 and 5 (minus) contacts, setting the measurement limits on the multimeter to 2 V. Turn on the ignition, but do not start the engine.

The scale shows 1.00 - the sensor is in excellent condition.

On a scale of 1.26 – the sensor is “dead”.

Check table

We evaluate the result using this table:

0.99-1.02 V	The condition of the air flow sensor is excellent, close to new
1.02-1.03 V	Sensor in good condition
1.04-1.05 V	The platinum thread is worn out, you need to think about replacing the sensor
More than 1.05 V	The sensor does not work, urgent replacement is necessary

Operating principle of DTOZH

The VAZ-2110 temperature sensor works as follows. The thermistor located inside the sensor is an electronic device with a negative indicator of heating modes. The mode of temperature values up to 130 degrees reduces the resistance within 70 Ohms, and the lower limits at -40° increase the resistance to 107 kOhms.

The detector supplies +5 V to the temperature sensor through a constant resistor located inside it. The element determines the heating level of the antifreeze thanks to the potential difference across a thermistor with variable resistance.

Where is it located?

Owners of cars of this model are well aware of various problems associated with this device. Often the device requires replacement. Beginners do not always know where the temperature sensor is located on the VAZ-2110. In cars, this element can be installed in a variety of places.

So, in classic models the thermistor is located directly in the cylinder block. And in AvtoVAZ models of the tenth family you can find DTOZH in the thermostat. By the way, on the VAZ-2110 there is not one temperature sensor - there are two, but the second one does not perform any important tasks. It is connected only to the instrument panel bottom temperature indicator.

VAZ-2112 sensors 16 valves and their location: diagram, photo, video

The efficient operation of the injection engine is ensured by a set of sensors. They all connect to the ECU. Lada hatchbacks of the 2112 family were produced only with injection engines, and two varieties of these internal combustion engines are 16-valve. We will talk about them further. All VAZ-2112 sensors, their location and appearance will be shown in the photo.

The excess oil pressure sensor, which is not connected to the ECU, is shown in the video.

Understanding the oxygen sensor

It is necessary to determine the sensor articles not by the engine model or even by Euro standards, but only by the ECU unit.

The number of oxygen sensors can be two or one - it all depends on environmental standards. AvtoVAZ also used two types of sensors - 0 258 005 133, 0 258 006 537 (BOSCH part numbers). The first of them are compatible with BOSCH M1.5.4, MP7.0 and January 5.1 controllers. Newer sensors were connected to the BOSCH M7.9.7 ECU (January 7.2). The two different types of sensors differ even in appearance.

The ECU unit in “Dozens of VAZs” is located under a plastic cover. It is located near the front passenger's foot.

The red arrow marks the first, that is, the main sensor. The top photo corresponds to engine 21124 (1.6 l).

VAZ-21120 engines (1.5 l) could meet the Euro-3 standard, and then an “extended” catalyst was welded behind the main sensor. The second sensor was located behind it, that is, behind the “can”. Let's clarify:

The Euro-2 standard corresponds to a design with one sensor (main);
During the transition to Euro-3 standards, a second sensor was added (blue arrow).

By the way, the 24th engine can meet Euro-4 standards.

Main set of sensors for 16-valve VAZ-2112 engines

The ECU must control many parameters at once

The most important information will be the position of the crankshaft. You can turn off all sensors except the DPKV, and this will not lead to the engine stopping.

Let's list all the elements one by one:

Let's take a look at how all the elements look in real life. Shown are pictures of VAZ-2112 sensors (16-valve internal combustion engine).

Everything said above is true for two engines at once - for units 21124 and 21120 (1.6 and 1.5 l).

You cannot unscrew the DTOZH sensor without draining the coolant. And to disconnect the sensor means to disconnect the connector, but not to dismantle the sensor itself.

Where is which sensor located - engine compartment diagram

Let's look at another picture.

It is important to understand where the following elements are located:

DPKV;
Lambda probe;
Speed sensor;
RXX;
TPDZ;
DMRV;
DTOZH.

The location of the phase sensor is indicated in the previous chapter.

Never unscrew the speed sensor. It will be difficult to install it in a way that maintains a seal.

Articles

For oxygen sensors, the designation 21120-3850010 was first used. Then an article appeared with the numbers 1118 (see photo). It appears to be a new type of sensor. It will be easier to use BOSCH articles.

We list the article numbers of the remaining sensors:

Mass air flow sensor (21124 or 21120): 21083-1130010-01, -10, -20;
Mass air flow sensor (motor 21120 with ECU January 4.1): 2112-1130010, -01;
DPDZ: 2112-1148200;
РХХ: 2112-1148300-02;
DPKV: 2112-3847010, -01, -03, -04;
DTOZH: 2112-3851010, -01, -02, -05;
Speed sensor: 2110-3843010-13, -18;
DPRV: 2112-3706040, -02, -03;
DD: 2112-3855020, -01, -02, -03;
Oil pressure sensor: 2106-3829010, -01, -02;
Antifreeze level sensor: 2110-3839310-10, -11, -12, -13, -14;
Coolant temperature indicator sensor: 2101-3808600, -02, 2106-3828010.

The last three sensors are not connected to the ECU. However, a rough road sensor (2123-1413130) can be connected. It affects the operation of the engine, although it is attached to the body.

Engines with ECU January 4.1 do not have oxygen sensors.

In general, on VAZ-2112 hatchbacks, sensors may be different from those indicated in the list. But then we are talking about an 8-valve engine. And everything that we indicated applies to 16 valves, here is a diagram of this engine.

carfrance.ru

Sensor malfunctions

As you know, the ratio of fuel and air in the combustible mixture depends on the readings of the device. All owners have already encountered or will continue to encounter various problems that the temperature sensor creates. It also determines whether the fan will start when overheated or not.

You can suspect a malfunction of the coolant sensor on a VAZ-2110 based on the following symptoms. So, the first signs are problems starting the engine on a cold frosty morning. You may also experience poor exhaust and fuel consumption will be significantly increased.

These symptoms do not necessarily indicate that the sensor needs to be replaced. Sometimes it is enough to clean the contacts and clean the sensor itself from corrosion. If a visual inspection fails to identify problems, then you need to check the element.

When is replacement required?

Checking with your own hands and replacing the temperature sensor on a VAZ 2112 with an injection 16-valve engine is not difficult. Repair of this part is not advisable. If problems arise, you must purchase a new part. A faulty temperature sensor can cause serious problems.

First of all, the engine overheats. If incorrect data is sent to the ECU, the cooling fan will not turn on on time. Consequently:

antifreeze will boil away;
the radiator or other components of the cooling system may burst;
the engine will overheat.

Therefore, it is advisable to replace it at the first sign of a malfunction of the temperature sensor. Main symptoms of failure:

The radiator does not turn on - it starts only at the “command” of the temperature sensor;
problems when starting the engine - this is especially acute during the first cold weather;
when the engine is not warmed up - poor exhaust;
the appearance of steam from the engine - this indicates overheating of the unit;
Fuel consumption has increased significantly when outside temperatures are above zero.

The price of a temperature sensor is no more than a few hundred rubles. Therefore, it is advisable to purchase a spare one in advance. This will avoid problems associated with finding the part. If you suspect that the sensor is not working, you should replace it immediately. The part is not repairable.C

Sensor diagnostics

All car owners should know how to check the temperature sensor on a VAZ-2110. By checking, you can save on the cost of a new device, although its price is not entirely high.

You can test the element by heating it. You need a suitable container. It could be a glass or a teapot. Hot water is poured into it. The water should be heated to approximately 100 degrees - the heating should be monitored with a thermometer. Next, the working part of the device is lowered into water. However, it is precisely the part of the temperature sensor that is located in the motor that needs to be lowered. Contacts must not be in water. Then a multimeter is connected to the contacts and the resistance is measured.

A working sensor at a liquid temperature of 100 degrees has a resistance of 177 ohms. At +50 degrees the resistance is 973 Ohms. If the values do not correspond to the norm, then the faulty element should be replaced. If the indicators are within these norms, then everything is in perfect order.

Location and service life of the controller

Description of the electrical equipment diagram of the VAZ-2112

On a VAZ-2112 with engines with 16 valves, the measuring device is located at the exhaust pipe, between the exhaust manifold and the coupling. To replace the device, you must gain access to the underbody of the vehicle body. For the best convenience, you need to drive the car into a garage with a pit or drive onto an overpass located near the highway.

The service life of the oxygen sensor may vary. If a motorist uses a high-quality fuel mixture, the service life will be up to 110 thousand kilometers. In the case when a low-quality mixture is used, the service life is reduced to 85 thousand kilometers.

How to remove

First of all, they look at what is preventing you from getting to the thermostat and sensor. The air filter housing is in the way - it needs to be removed. Next, it is recommended to drain the antifreeze from the engine, but this is not always necessary. When replacing, only a little fluid will spill, and you can always top it up to the level.

Then, after draining the liquid, remove the terminal from the battery, select the desired sensor and remove everything connected to it. After disconnecting, the element is simply unscrewed, holding its edges with your hands or a key. After this, the device can be removed.

Operating temperature and causes of engine overheating

Under normal conditions, coolant circulation ensures a temperature of 86-90 °C. During hot periods, the indicator may lag, then after turning on the fan, the temperature stops at 94-108 °C. A frequent question from car enthusiasts: what is the temperature in winter when it’s cold? The first 10-15 kilometers the indicator may be below 80 °C, but after this point it should rise to 85-90 °C. These data are suitable for VAZ 2110 injector.

Now you know what the normal operating temperature of the VAZ 2110 is, so it’s time to study the reasons for its excess. If the “culprit” of the overestimated indicator is not the DTOZH, then the following actions should be taken:

Check the outer part of the radiator for contamination.
Replace the thermostat in the VAZ 2110 injector.
Check the coolant level in the expansion tank; if it becomes low, add it to the required level.
Adjust the ignition timing.
Check that the fan is turned on.

Installing a new coolant sensor

The new coolant temperature sensor on the VAZ-2110 is installed in the reverse order. Experienced motorists recommend lubricating the threads of the element with sealant.

Sometimes coolant leaks are observed from under the new sensor. The replacement process is extremely simple and even beginners who just got behind the wheel and didn’t know anything about cars can handle it without difficulty.

Replacement

Fuses and relays VAZ 2114. location. description

The check showed that the sensor was to blame. Therefore, you have no choice but to replace it with a new one. For this:

The coolant is drained. It is better to drain the maximum amount. Especially if the coolant has long been due for replacement;
Disconnect the terminals from the battery;
To make it more convenient to work, remove the air filter from its seat;
Turn off the ignition and remove the sensor connector;
Use a 19mm wrench to remove the sensor. The sealing ring must be removed along with it;
A new seal ring is taken and a new, high-quality coolant sensor, suitable for the VAZ 2110 model, is mounted in place of the old one;
The entire assembly process is performed in reverse order.

The coolant temperature sensor for the VAZ 2110 plays an important role. The owners of this model know very well that its failure is not a rare situation. The good news is that the replacement procedure is not complicated and can be carried out by any driver, even whose driving experience does not exceed several days.

As for the cost of self-repair, you only need to purchase a new O-ring and the sensor itself, of course. Today, a good quality device for a “ten” costs about 200 rubles. The tools are only the most standard ones, so you won’t have to buy anything or spend any extra money.

A professional will do the work at the auto repair shop, but the cost of the repair will be appropriate. Plus, many service stations use cunning moves, trying to force the car owner to perform a number of additional measures. Sometimes they are really useful, but sometimes they are just an attempt to get more money out of you.

Decide for yourself whether it’s worth taking the car to a service center to replace the TOZ sensor, or whether you can calmly complete the entire procedure yourself in an hour, but save a decent amount of money.

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