Temperature sensor VAZ 2115 - frequent malfunctions, replacement, diagnostics

Checking the temperature sensor is a simple procedure that even a novice car enthusiast can handle. The coolant temperature sensor (abbreviated as DTOZH) is a thermistor, that is, a resistor that changes the value of its internal resistance in accordance with the temperature where its actuator is placed. Most often, a multimeter is used for this (another name is a tester, “tseshka”), which is able to measure the value of electrical resistance in a circuit.

Where to find a temperature sensor in a VAZ-2115

The entire cooling system in cars is divided into several types:

• air;
• liquid;
• combined - combining 2 types at once.

The VAZ-2115 has a built-in liquid cooling system, which involves filling with antifreeze or higher quality antifreeze. In general, the mechanism consists of the following functional elements:

• a radiator that allows the engine to cool;
• radiator fan;
• heater radiator;
• cooling device jacket;
• pump pumping coolant;
• expansion tank;
• connecting pipes;
• antifreeze temperature sensor.

Beginners are wondering where the coolant temperature sensor is located on the VAZ-2115? The unit located between the thermostat and the head of the cylinder combination, directly on top of the cooling system pipe, connects the part to the system using 2 wires.

There is another meter installed nearby, but note that this additional unit is connected on one side to the instrument panel.

A careful study of the design allows you to see a resistor in the sensor, where the resistance is determined depending on the heating of the VAZ-2115 engine.

Procedure for removing DTOZH

Twisting

You understand perfectly well that the coolant is called that for a reason. And if antifreeze boils in the expansion tank of a VAZ 2114, can this be considered normal? Not at all. It is not uncommon that the problem lies precisely in a faulty DVT.

To replace it, you need to perform several sequential steps.

1. Drain the coolant. For this:

1. Wait until the engine cools down if you have just driven into the garage;
2. Arm yourself with ring wrenches for 17, 13 and 8;
3. Take a container into which the coolant will be drained;
4. Remove the engine protection, disconnect the radiator fasteners;
5. Turn on the stove to maximum mode and open the heater tap along with the expansion tank cap;
6. Place a container under the radiator and very carefully begin to unscrew the drain plug. High pressure releases antifreeze from the expansion tank of the VAZ 2114, so you need to act slowly;
7. Over the course of 10 minutes, the liquid will gradually drain;
8. At this time, go to the engine, place the same container under it and unscrew the plug from the cylinder block, which is located directly under the ignition module;
9. You will have to wait about 10 more minutes for the liquid to drain out.

• Now removes the old coolant temperature sensor:
• Find it on your car;
• Look at the body, pay attention to the markings on one side of the hexagon. Remember the position so that when reassembling everything, do it the same way;
• The meter is dismantled using a 21 key;
• A new meter is being installed.
• We install a new device. For this:
• We purchase a new TOZh sensor;
• Using the same 21 key, we mount it in place of the old one;
• We take into account the previously remembered markings and install the new sensor in a similar position;
• We apply a little heat sealant to the threads, which will ensure a high-quality connection;
• Coolant is refilled into the heating system and cylinder block. Just use a new one, even if the old one is in good condition. Look at the coolant level sensor on the VAZ 2114 to make sure the tank is full.

If after these manipulations the DTOZH still does not work, pay attention to several points:

1. You may have screwed the new sensor into its seat poorly;
2. It is possible that you forgot to fill the coolant;
3. A leak of cooling liquid formed in the system, the generator was splashed with it;
4. The new sensor could be defective. In this case, it is recommended to always leave the purchase receipt until you are sure that the sensor is working properly. Unfortunately, it is impossible to verify this on site.

Not all issues can be resolved on your own, no matter how experienced an auto mechanic you are. Sometimes you have to go to a service station. But here, too, you must be sure that the specialists are competent, their equipment is in good working order, and they have enough experience in order to efficiently solve the problem that you and your car have. Make good friends at car repair shops. Even if you visit them once a year.

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Temperature meter sensor malfunctions

Knowing the location of the device, it is easy to get rid of the breakdown yourself. The main reasons for the incorrect operation of the device, according to experts, may be:

• lack of contact;
• rupture and wear of insulation, loss of contact integrity;
• the device is completely out of order;
• The fan is not working well.

Signs that should alert the driver of a VAZ-2115 and prompt them to diagnose the condition of the antifreeze temperature sensor may be:

• fan operation when the machine engine is not warmed up;
• the engine is warmed up, but still refuses to function;
• Fuel costs are gradually and steadily increasing.

How to check the temperature sensor for serviceability

DTOZH signals the heating temperature of the antifreeze on the instrument panel of the VAZ-2115.

The condition of the device can be easily checked by following these instructions:

1. Start the car and watch the instrument panel readings. When the arrow is fixed at the maximum value and the engine is cold, disconnect the contacts from the temperature measuring device. If the arrow suddenly drops to the possible minimum, then the unit is really out of order and needs to be replaced.
2. If the arrow is still at the maximum, consider the contact; perhaps it is shorted to ground on the VAZ-2115.
3. If the engine heats up well, but the needle continues to jump or is opposite the zero value, start checking the wear of the fuses.
4. If the fuses are not worn out, then it remains to close the contact to ground of the VAZ-2115. Monitor the position of the arrow; if it shoots up, it means the VAZ-2115 DTOZH is not functioning correctly.

How else to check the DTOZH:

1. You will need a multimeter, it should be set to ohmmeter mode. Also equip yourself with a thermometer that can measure temperatures greater than 100 degrees. Prepare a container that will not melt under the influence of hot coolant.
2. Fix the multimeter probes to the body base and the terminal of the measuring device.
3. Place the attached sensor directly into a container with antifreeze and heat it well.
4. Look at the thermometer and ohmmeter readings. At a temperature of 30 degrees, the resistance should be equal to 1350-1880 Ohms. If the temperature rises to 50 degrees, the resistance decreases to 585-820 degrees. A temperature of 70 degrees corresponds to a resistance from 280 to 390 Ohms inclusive. If the antifreeze is heated to 90 degrees, the normal resistance value is in the range of 155-196 Ohms. At 110 degrees the resistance is the lowest - from 87 to 109 Ohms.

How to change the temperature sensor on a VAZ-2115

The instructions for replacing the VAZ-2115 DTOZH are clear even to a beginner:

1. Dismantle the old model, first draining the antifreeze from the car.
2. Using the key number 21, place the new unit in the right place.
3. Apply heat sealant while tightening the threads.
4. Fill in new antifreeze; before using this special product, it is advisable to clean the entire cooling system.

Why the new unit may not work:

1. You may have bought a defective device, which is why experts recommend checking the serviceability of the product with a multimeter.
2. If there was an antifreeze leak, there is a possibility of the generator getting dirty.
3. Screw the sensor tighter.

Step-by-step video instructions for replacing the coolant temperature sensor can be viewed below:

Temperature sensor for VAZ 2115

The VAZ 2115 line of cars was equipped with injection engines with electronic control units (ECU). The system collects readings from several controllers, and then adjusts the balanced operation of the engine. The coolant temperature sensor on the VAZ 2115 (DTOZH) is one of the main controllers, thanks to which the crankshaft speed, the proportion of the gasoline/air mixture, as well as the ignition are regulated. Next, we will tell you where the t° sensor is located on the 2115 Samara engine, what symptoms indicate its problems, and how to replace the defective device.

Attention ! The VAZ 2115 has two types of water t° sensors. The first 1-pin - sends information to the instrument panel. The second 2-pin is responsible for starting/stopping the radiator fan and exchanging readings with the ECU. In this article we will talk about the second type (hereinafter referred to as DTOZH).

The main problems with DTOZH on the VAZ-2114

DTOZH is a full participant in the engine control system. Unlike the temperature indicator sensor, its purpose is to transmit readings to reading devices. DTOZH is a sensor that influences the correct operation of the engine and the VAZ-2114 vehicle as a whole.

1. The device helps maintain the stability of all components of the car.
2. Thanks to the device, accelerated warming up of the engine is ensured and overheating is eliminated.

Listed below are signs that may indicate that the TOZ sensor on the 2114th Zhiguli model has become unusable and requires replacement or repair.

1. The engine starts to stall, runs with a delayed start, and malfunctions occur.
2. The number of idle speeds decreases from 600-800 to 200-150. And instead of a stable rumbling, the engine makes sounds reminiscent of coughing and crunching.
3. Increased gasoline consumption.
4. Failure in the correct operation of cooling coolers: they turn off in warm weather and turn on in cold weather.
5. The appearance of inclusions in exhaust gases. Dark smoke flies out of the chimney.
6. The engine warm-up time increases.
7. The engine gets very hot.

Principle of operation

The two-contact temperature sensor on the VAZ 2110–2115 family is a resistor mechanism with a negative temperature coefficient. That is, in the cold its resistance is high, and when heated, on the contrary, it is low. During operation, the DTOZ transmits impulses to the ECU. The device has 2 contacts: one for communication with the control unit, the second for starting/stopping the radiator fan.

Table 1. Units of measurement of water temperature and data on DTOZH VAZ 2115

Information for self-checking with the meter

Simply put, the VAZ 2115 temperature sensor (8-valve injector) performs one of the functions of a damper (choke), which was traditionally located on carburetor cars. Having received readings from the DTOZH, the ECU system ensures that the cold engine is injected with a rich fuel mixture, and the hot engine is injected with a lean mixture.

Video “Procedure for replacing the MPV sensor on a VAZ car”

How to replace the regulator on the “ten” yourself at home - find out from the video (the author of the video is In Sandro’s garage).

The VAZ 2110 temperature sensor is an important element of the system; it informs the computer about the engine temperature. A lot depends on the engine temperature. For example, the lower it is, the richer the fuel mixture is supplied to the injector or carburetor.

Sometimes on the road you can see cars standing on the side of the road with steam pouring out of their open hoods. This is a fairly common situation when the engine temperature exceeds the permissible limits and the engine overheats.

The coolant sensor in the car failed or the car owner was distracted and did not notice that the temperature of the VAZ 2110 engine was going through the roof. Due to engine overheating, the liquid in the cooling system exceeded its boiling point and turned into steam. To somehow help the car cool down, the driver opens the cap on the radiator and releases steam, which comes out under pressure.

You shouldn't do that. This carries certain risks: you can get serious burns. To avoid such problems, the motorist needs to be extremely careful during the trip and promptly respond to information from sensors and instruments on the console. It is also important to ensure that the VAZ 2110 coolant sensor is in working order and its readings are accurate.

Causes and symptoms of malfunction

In most cases, if the temperature sensor stops working on a VAZ 2115, then most often the problems occur for natural reasons (for example, rupture of internal contacts). A faulty device sends incorrect engine temperature information to the control unit. And the computer reads the starting temperature of the engine as 0 °C, after which it orders another sensor, the mass air flow sensor, to add air, that is, to enrich the mixture. Sometimes problems arise because:

• the seal of the housing is broken;
• broken electrical wiring;
• The connector fell off the block.

As a result, the yellow “Check Engine” icon lights up on the panel. Thus, the ECU warns the driver about problems in the system. What symptoms on a working VAZ 2115 indicate that the temperature sensor “died a heroic death”:

• difficult starting, especially in frosty weather;
• floating speed until fully warmed up t 90 °C;
• strong detonation appears;
• power is lost;
• the engine stalls.

In addition to the listed defects, gasoline consumption increases noticeably, and dark smoke comes out of the exhaust pipe.

Signs of trouble

Typical symptoms of DTOZ failure are as follows:

• Turning on the fan when the engine is not warmed up;
• A warm engine does not start well;
• Unstable engine speed at idle;
• Unstable engine operation (triggering, lack of traction)
• Gasoline consumption increases;

If the DTUOZH fails, the engine runs stably, without interruptions, but on the dashboard you see that the liquid does not heat up or does not cool down at all. These are all signs of a faulty DTOZH on a VAZ 2114.

Possible reasons

The most common cause of such problems for DTOZH and DTUOZH are:

• Oxidation of terminals (contacts);
• Broken power wire;
• Damage to the sensor itself;

Where is the temperature sensor located?

The front-wheel drive family from Togliatti has a transverse engine installation. The VAZ 2115 temperature sensor is located between the cylinder block and the thermostat. It is located on the coolant flange located on the right side of the engine. The sensor is easy to see if you look down, between the head and the air filter housing. (A little lower, directly into the block, a 1-pin water t° indicator sensor is screwed in. 1 green wire goes to it).

Replacement instructions

On the VAZ 2114 model, the element we need is installed in the engine block, and not in the radiator block!

To check the coolant temperature thermistor with your own hands, you must first remove it. With model 2114 this is not very difficult to do. To do this you will have to:

1. Remove the air filter, because the sensor itself is located on the inlet pipe of the cooling jacket of the cylinder head;
2. Remove the negative charge cable from the battery;
3. Drain the coolant (coolant) from the radiator. If you have good repair experience, then you can do without this item, but it is recommended for beginners to perform this item;
4. Disconnect all contacts. Using a deep socket, unscrew the sensor;
5. After this, you can unscrew the sensor. If the bolts are too tight, use a wrench.

Unscrewing the DTOZH should occur carefully and gradually

Replacement

To install a new cooling sensor on the LADA 2115 Samara, you need to select a flat area. You will need a tool: open-end and spanner wrenches (19 mm, 13 mm, 10 mm, 8 mm), as well as a large medical syringe 100–250 ml, and a 15–20 cm dropper tube to it. It is recommended to buy the original sensor itself, here its number is 21120–3851010–05. It is easy to replace the DTOZH yourself. The step-by-step process looks like this:

1. Allow the engine to cool to at least 40 °C.
2. Use a syringe to pump out antifreeze/antifreeze from the expansion tank (so as not to drain the coolant).
3. Unscrew the negative terminal of the battery (10–13 mm wrench).
4. Disconnect the plug from the air flow sensor.
5. Unscrew the air filter housing (8 mm wrench).
6. Carefully removes the “pan” and moves it to the right.
7. Disconnect the plug from the DTOZH.
8. Unscrew the sensor (19 mm spanner).
9. Cleaning the landing area.
10. We screw in the new DTOZH.

Let's collect everything in reverse chronology. It is not recommended to use sealant, as the copper ring is perfectly crimped, ensuring a tight seal.

Summary

The coolant temperature sensor is an important element for the balanced operation of the VAZ 2115 engine. If it malfunctions, the car loses its driving characteristics: it starts poorly, stalls, loses power, consumes more fuel, and sometimes the engine does not work at all. You can replace the DTOZH yourself using a minimal set of tools.

TOZh sensors, from left to right: 1 Sensor for the fan, 2 sensor for the pointer, 3 a cleverly crafted old sensor of mine.

The conclusion is this: there are two temperature sensors - one for the “brains”, the fan, the on-board computer. (It screws in vertically, is easy to change, costs a little more. - the second one is on the arrow (single-pin, screwed horizontally under the pipe), behaves strangely when screwed in.

Now I will look for and ask for a sensor like my old one (in the photo with an orange neck). He gave me temperature readings exactly the same as on BC.

Kalina

The official version of the DTOZH for the VAZ 2112 is 2112-3851010. But you can use analogues, for example, ERA (33026), Luzar (LS 0112), Fenox (TSN 2211207).

The location of the sensor on a car with an 8- and 16-valve engine is near the thermostat. In this case, the device is slightly closed by the filter housing.

In this case, on the Lada Kalina 1 you will have to remove the air filter to access the temperature meter.

To unscrew, use a 19 key. There is no need to drain the antifreeze.

Check, as in the previous case, after removing the device with the key to “19”.

For temperature and resistance readings, see Table 3.

Checking the presence of operating voltage is carried out with a multimeter with the ignition on without removing the sensor between the block terminal “B” and ground (there are two terminals on the blocks “A” and “B”), standard readings are within 4.8-5.2 V.

Features of the DTOZH operation on the fifteenth VAZ model

The coolant temperature sensor (CTS) relates to the cooling system of the machine. Its purpose is to control the coolant temperature. While the engine is cold, the ECU sets an enriched fuel assembly; after the engine warms up, it becomes normal.

The device is a resistor called a thermistor placed in a metal case.

Device diagram

The resistance of the thermistor increases as the temperature decreases, and at the same time the voltage supplied to it will increase.

Video on the topic

The domestic VAZ 2115 car has an engine with an injector and an ECU, which monitors changes in engine operation and gives appropriate instructions. To monitor the operation of vehicle components and assemblies, special sensors are used.

Possible sensor malfunctions

If the DTOZH breaks down, the ECU considers that the engine temperature is zero, so it enriches the combustible mixture. A broken device must be replaced as quickly as possible. Most often, a meter malfunction is a calibration violation. In this case, the resistance does not change correctly, and since the control unit is based on meter readings, it does not work correctly.

You can identify a DTOZ malfunction by turning on the fan. It should turn on if permissible values ​​are exceeded. True, there is also a fan switch sensor, which can also fail.

Thus, the fan may not turn on if:

• contacts have oxidized;
• wiring is damaged;
• sensors are faulty.

Incorrect operation of the DTOZ leads to increased fuel consumption, detonation, and high idle speeds. The most dangerous thing is if the engine temperature sensor is broken. In this case, the fan does not start, there is no cooling of the engine, it overheats, and as a result, the cylinder head may misfire.

Methods for checking the regulator for operability

Before checking the meter, you should first check the serviceability of the fuses, the integrity of the wiring and measure the incoming voltage, which should be 5V. If there are no wiring faults and the voltage is normal, then the meter is checked for resistance. To check it, you need to remove it (the author of the video is Car Design and Repair).

To check, you will need an electric kettle, a thermometer to measure the outside temperature, and a multimeter set to resistance measurement mode.

It is advisable to take an electronic thermometer not to measure the outside air temperature.

There are two ways to check:

1. In the first case, the coolant temperature sensor with a thermometer is placed in an electric kettle. In this case, the device must be connected to the tester. The electric kettle should be plugged in and monitor the readings. As the temperature increases, the resistance should increase. When it becomes +15 degrees, the resistance should be 4450 Ohms, +40 - 1459 Ohms. At 100 degrees, the resistance reaches a minimum of 177 Ohms. If the values ​​are different, this indicates a malfunction.
2. If there is no thermometer, then the meter is checked after the water boils. When immersed in freshly boiled water, the multimeter should display a resistance of slightly more than 177 ohms. Otherwise the device is broken.

Checking with a multimeter