High-quality operation of a car’s heater in winter is one of the main conditions for comfortable driving. In domestic vehicles, even in new models, the heater is one of the problematic elements that very often fails. And if in the summer you can turn a blind eye to this, then in cold weather you immediately have to take measures to eliminate the problem.
To eliminate the malfunction, it is first important to diagnose which element of the car’s heating system has failed and repair the non-functioning unit. The easiest way is to turn to specialists for help, but their services are not very cheap. Very often, vehicle owners troubleshoot and repair the heater on their own, since domestic cars are highly maintainable.
Heater regulator on the dashboard of a VAZ 2110
This article will talk about how to diagnose a malfunction of the VAZ-2110 heater control unit and repair it yourself.
Design of the heating system VAZ-2110
It includes three main nodes. This is a control unit for the VAZ-2110 stove, an air duct system, and a heating unit. The stove is controlled via an electronic unit. It consists of knobs with which the driver sets the required temperature and fan intensity.
The unit also includes a temperature sensor. As for the latter, it is necessary to automatically start the stove when the temperature inside the car drops more than two degrees below the set one. The sensor is equipped with a small fan. If you move the knob on the controller to position A, then a small electric motor is started in the heating unit, which controls the damper. The temperature sensor itself in the VAZ-2110 can be found on the ceiling, near the lighting lamp.
Another important component of the heating system is the air ducts. They pass directly from the stove itself, and each channel has its own separate function. Thus, the central channels are designed for interior ventilation.
The air distributor is responsible for supplying cool air to the cabin for ventilation or warm air for heating. The other two air ducts are designed to heat the interior in the back row. The rest are also intended for ventilation. Two side channels heat the mirrors and part of the interior. Separate nozzles are used to heat the driver's feet.
Functions and main malfunctions of the interior temperature sensor
The heating system in cars of this brand is controlled by a signal method. The impulses come from the electrical control unit. Temperature is a factor affecting every system controlled by the unit. The essence of its work is to compare the indicators on the sensor (16-30°C) with the real heat intensity, which is measured by it.
When a temperature difference is detected, the motor turns on. Its function is to change the flow of warm air using dampers and fan speed. The cabin air temperature sensor is a thermistor or semiconductor resistor, which has a close relationship between thermal state and resistance. From the control electrical unit, voltage is supplied to this device through a resistor located inside.
One of the most traditional defects of this device, which operates on the basis of a semiconductor thermistor, is the discrepancy between the temperature of the external part and the resistance. To correct this discrepancy, you need to know the main features of its work. Typically, this defect manifests itself in a rapid increase in resistivity with small fluctuations in the degree of heating of the outer part.
In addition, there may be a break in the electrical circuit of the sensitive element of the converter itself, which is why you will have to buy a new interior temperature sensor. Periodically, a situation arises in which the thermal state of the device shell varies over a certain small range, and the resistance increases disproportionately with voltage. As a result, the heat calculated by the block turns out to be less than in reality.
Block responsible for temperature
The central unit in the stove system is the heating unit. Its main function is to directly heat the interior. This block is arranged as follows. An electric motor with fan blades pumps hot air, three dampers perform the function of recirculation and closing/opening the channels. There is also a heater core. On modern new generation systems, heat exchangers are not equipped with a tap.
Therefore, the radiator is always heated, regardless of the time of year. The manufacturer claims that this has solved the problem with constant faucet leaks. In addition, heating of the interior is significantly faster. In summer, supply ventilation occurs outside the radiator.
Modernization of the damper on the VAZ-2110
Malfunctions with the damper often result in the interior heating very poorly and slowly. The VAZ-2110 stove control unit is to blame. The controller is experiencing problems. The device does not send a command to extend the flap. In this case, it is recommended to check the temperature sensor. The controller handle is set to its extreme position and then twisted several times from the left to the right position. The temperature of the air flows must be checked by hand. In this way, the operating condition of the sensor is checked in one of the extreme positions of the handle. If the air flow changes the temperature when the knob is in the extreme position, then the sensor must be replaced. If the heating does not change, the cause is looked for in other places.
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SAUO pinout:
The SAUO receives information from:
- – cabin air temperature sensor (No. 6), which has a built-in small-sized fan.
- – MMR (micromotor reducer) (No. 9), information about the position of the heater damper.
Damper control : Based on the received information and the set air temperature, the controller controls the position of the heater damper, sending appropriate signals to the damper drive micromotor.
Fan problems
This will be indicated by noise or strong squealing while the car is moving. First you need to find out what is causing the fan failure. In some cases, the lower part on the heater housing falls off. Then the hooks are installed in place, which serve as fastenings.
However, it is more common to see broken tabs on the heater unit housing. Here the housing needs to be replaced. Another reason is uneven shaft expansion coefficients if the fan is heavily worn. In this case, experts recommend replacing the stove motor or its bushing. Sometimes the fan makes noise because of the washers, which are used to eliminate axial play. The element needs to be removed and cleaned. Replace the washer with a fluoroplastic one, then lubricate everything well.
Causes of poor foot airflow
Heater malfunction
Air through the cabin filter is taken from the street by the rotating blades of the electric heater motor. Through a damper system, air is distributed through air ducts and supplied into the cabin through deflectors and non-adjustable grilles.
Air, like any gaseous medium, tends to follow the path of least resistance. Therefore, it is logical that the air flows first come out of the central and side deflectors. The feet of the driver and passengers are blown last. Structurally, the air ducts to the central deflector and the upper side airflow points have a larger cross-section, and it is much easier for air to pass through them.
Initially, you need to make sure that nothing interferes with the intake of air from the atmosphere. After all, if the air is supplied in insufficient volume, then it will not be enough to supply all airflow points with the intensity that was calculated at the design stage of the car.
Check the condition of the cabin filter. To do this, remove the wipers and frill. The cabin filter is located on the right side of the vehicle under the windshield. It is covered with a plastic casing, which is secured with four self-tapping screws. Unscrew the screws and remove the cabin filter. We start the engine, warm it up to operating temperature and check the operation of the stove. If the situation has improved, change the cabin filter and close the issue.
The second common cause is a clogged heater core. In this case, the heating of the interior will be weak, because warm air does not come out of all the deflectors well, and not just into the legs. But the fact is that when driving for a long time, your feet begin to freeze first, so it seems that the problem is in this part of the airflow.
Video: Why the stove does not blow at the feet of VAZ 2111,2110
This malfunction is easily diagnosed. We find two pipes for supplying antifreeze to the heater radiator (rubber hoses on the left side in the direction of travel of the car). With the engine warm, carefully touch the two pipes one at a time with the heater running at full power. The difference in temperature between the pipes should be minimal. If one pipe is hot and the second is cold or barely warm, we wash or replace the heater radiator.
Checking the operation of the dampers
There are nine exit points for air flows from the heater on the VAZ-2110:
- central deflector;
- two side deflectors and two windshield air vents;
- heated feet of the driver and front passenger;
- two outputs for heating the feet of rear passengers.
In an ideally operating system, the pressure generated by the heater motor is sufficient to create an effective flow to warm the feet. However, over time, gaps form in the joints of the air ducts, and the dampers of the VAZ-2110 heater begin to fit loosely to the body. This leads to atomization of the air flow. As a result, a minimum amount of air reaches the distant exit points.
First, dismantle the panel with the central deflector. It is held in place by four plastic clips. To remove it, simply pry it off one of the sides with a suitable object, such as a flat-head screwdriver. Be careful: the clips are fragile.
Evaluate the damper's performance
In older cars with a manual damper drive, pay attention to the play in the linkage of the rods. A broken rod system will not allow the damper to fit tightly to the body in the extreme position, which will cause air to leak from the cold circuit
The problem is corrected by adjusting the damper. In a mechanical drive, it is possible to shorten the rod due to a movable lock on a gear rod or a threaded tip. During the adjustment process, check that the position of the switch on the panel corresponds to the actual position of the damper.
Another reason why the VAZ-2110 stove does not blow into your feet is a malfunction in the operation of the automatic heater control system (AHC) unit or the gear motor of the VAZ-2110 stove. In this case, there is usually insufficiently warm or even cold air from the stove operating in maximum heating mode. This is due to the incorrect position of the damper in which the gearmotor sets it.
Evaluate the operation of the gear motor of the VAZ-2110 stove. To do this, visually check how it closes the damper when switching modes. The easiest way to do this is to remove the panel with the central deflector. Move the temperature knob to the extreme position (for example, set the minimum temperature), then sharply switch to the opposite mode. The damper should completely block the channel visible from the driver's position. If this does not happen, the problem lies in the gear motor or the automatic control system unit. Check the serviceability of the gearmotor and unit.
If the stove does not work at first speed
Each fan speed (except the last) is connected through a separate heater resistor.
It is located not on the controller, but under the frill. One of the reasons for the inability to work at first speed is a faulty resistor. If the second speed does not work, then the reason is the same. But malfunctions can also be due to defects in the contacts on the board. Often, due to high temperatures, the board becomes very hot. As a result, contacts come loose. The entire board must be checked thoroughly. They look more carefully where food is served.
Drawing conclusions
In the article, I tried to describe in detail almost every case of a possible breakdown of the stove in a VAZ 2110 car and added a couple of tips and personal stories of my own. But I also want to tell you one more case in my practice. So I bought a car, by the way, it was a VAZ and winter came, the stove didn’t work.
I started looking for reasons, tried everything, nothing helped. I even changed the radiator and paid a large amount for it, but the stove never worked in the end. Three months later, by pure chance, I took out a tube coming out of the stove and three huge holes were made in it on the right.
Through them, all the warm air went out into the street without warming up the interior. As it turned out in the end, there was a defect at the factory and therefore the car was sold to the first owner at a discount. He was not upset and simply covered the holes with cloth. Over the years, the fabric tore and the stove stopped working.
Therefore, try to check all possible options for a stove failure in any car.
Replacing self-propelled guns
Control units cannot be repaired - they are simply replaced with new ones. But first you need to make sure that this mechanism is the reason. Instead of a broken one, install a working control unit. Its price is about 1500 rubles. The element is very easy to dismantle: just remove the buttons installed nearby. And then you can remove the device. The handles are set to zero positions and then removed.
Then the glass and front cover snap off. Before removing the heater control unit on a VAZ-2110, unscrew two screws in the front and one in the back. The board can then be pulled out of the case and carefully inspected to ensure its integrity. If there is damage to the board tracks, they must be repaired. Subsequent assembly is performed in reverse order. If the temperature on the control unit is not regulated, then the entire board should be inspected. There will definitely be defects. But before you pull out the heater control unit on the VAZ-2110, you need to check the fuse box. Perhaps there is a bad connection there.
Diagnostics of serviceability and dismantling of the stove control unit
The SAUO module is located on the center console of the car and is responsible for proper heating of the interior. Repairing the VAZ-2110 stove control unit requires certain knowledge of electronics, therefore, before you begin repairing the part, you need to determine whether the problem is really in the electronic module itself.
To do this, it is necessary to initially disassemble the unit and install a deliberately repaired part in its place. Take the SAUO unit to a friend or service center to diagnose your car's heating system.
Before performing any electronic or wiring work on your vehicle, disconnect power from the battery to prevent short circuits or burns to electronic components.
Then you can proceed directly to disassembling the cabinet, through which the functionality of the stove is coordinated. To do this, initially disassemble the buttons on the sides of the stove. The heater controls must be moved to the zero position. Only after this the module can be removed. This must be done very carefully as the power plugs are connected to the back of the device. Once you see them, you should carefully unplug them to avoid damaging the contacts. At this point, dismantling can be considered complete.
The working unit is installed on the standard seat and the operation of the vehicle heating system is checked. If the stove works correctly with the new group, then the fault is in the ACS group itself. Otherwise, it is necessary to diagnose other elements of the heating system.
Setting the air temperature from the heater
You can set the desired temperature in the cabin using the adjustment knob. But for a more accurate result and adjustment, the block has a special screw. To check the accuracy of temperature control, close all doors and windows. Place a control thermometer in the sensor area.
Then the element is set to automatic mode, and heating is monitored using a thermometer. How long can the control unit of the SAUO VAZ-21102 stove be adjusted in time? The procedure takes no more than half an hour. If after 15 minutes the actual temperature does not correspond to the set one, then the block is removed. Turn the adjusting screw clockwise. If you rotate the screw clockwise, the temperature will increase, if counterclockwise, it will decrease. Then install the element in place and check that it is working correctly. As for the possibility of repairing faults, the control unit for the VAZ-2110 stove of the new model cannot be repaired (however, like the old one). In case of serious malfunctions, it is replaced entirely. Moreover, the cost is low.
So, we found out why the stove does not work and how to solve this problem.
Electronic control of the VAZ stove: understanding the electronics
The VAZ-2110, 2111 and 2112 are equipped with an automatic heater control system (ACS), which in turn creates a temperature in the car set by the driver. A kind of air conditioner without air conditioning, a winter option. The brain of the system is controller 3 according to the 13.3854 type circuit with two control knobs. With the left knob we adjust the temperature in the cabin (from 16 to 30 ° C), with the right knob we adjust the fan: 0 - off; I - average speed; II - low speed; A - automatically. So, here is a breakdown of the VAZ-2110 heater circuit
- fan motor;
- additional resistance;
- controller;
- mounting block;
- ignition switch;
- internal temperature sensor;
- recirculation switch;
- recirculation valve;
- micromotor control of the heater damper;
A - to the instrument lighting switch;
B - to power supplies
If the heater motor stops working, check fuse F18 in the mounting block
SAUO controllers (automatic heater control system). On the left - with automatic mode - primitive climate (tied to the temperature sensor under the ceiling). On the right is the more common 4-speed. Once connected, they are compatible with the standard wiring of the VAZ 2110, with the exception of heating the MMR sensor (enough to start it).
