Design features of the VAZ-2110 stove control unit and the specifics of its do-it-yourself repair

High-quality operation of a car stove 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, which very often fails. And if in the summer you can close your eyes to this, then in the cold you immediately have to take measures to eliminate the problem.

To eliminate the malfunction, for a start, it is important to diagnose which element of the car's heating system has failed, and. The easiest way is to turn to specialists for help, but their services are not very cheaply priced. Very often, vehicle owners are engaged in troubleshooting and repairing the heater on their own, since domestic cars are highly maintainable.

This article will discuss how to diagnose a malfunction of the VAZ-2110 heater control unit and repair it yourself.

Design features of the VAZ-2110 stove control unit

One of the common problems of the heating system that the owners of the VAZ-2110 face is the failure or malfunctioning of the stove control unit. Dozens from the factory are equipped with stoves, which are coordinated through an automatic heater control system. In abbreviated form, the system is called the SAUO block. The main indicators of its malfunction is the operation of the heating system not in all modes. If one or several stove speeds do not work, then most often the problem is in the SAUO unit. Thanks to the VAZ-2110 electronic module, the temperature set by the driver is maintained in the car.

Heater automatic control system diagram: 1 - fan motor; 2 - additional resistor; 3 - controller; 4 - mounting block; 5 - ignition switch; 6 - cabin air temperature sensor; 7 - recirculation switch; 8 - recirculation valve; 9 - micromotor drive of the heater flap; A - to the instrument lighting switch; B - to power supplies

Before proceeding with the repair of the VAZ-2110 heater, you need to find out which stove is on your vehicle. Cars that were produced before September 2003 are equipped with old-style stoves. Accordingly, there are significant differences in the design, which are important to pay attention to when repairing.

The SAUO unit consists of electronic elements, the coordination of which takes place with the help of handles on the central console of the machine.

The VAZ-2110 stove control unit is equipped with a controller with two handles. The right handle is responsible for turning on a certain fan speed. An additional resistor is directly responsible for switching its speeds. Old-style stoves have resistors for two or three fan speeds. The stoves of the new model are equipped with a modified resistor RDO 2123-2118022. The coordination unit of the improved stove model has four speeds and does not have an auto mode.

The left handle is responsible for turning on the temperature regime in the vehicle interior. Depending on the position of the handle, information about the preset air temperature is sent to the micro-reducer of the damper drive and, with the help of the controller, the required damper position is set. With the help of the regulator, you can set the temperature regime from sixteen to thirty degrees Celsius.

Until 2003, old-style stoves with four- and five-position controllers were installed in cars, which have now been discontinued and are very difficult to find. And also a simple VAZ-2110 heater control unit is not suitable for car models that were produced after 2003 and are equipped with modified stoves from the factory.

Accordingly, before buying parts for repairing a vehicle's heating system, you need to look at which heater model is on your top ten. Stoves differ not only in the SAUO unit, but also in the heater radiator, micro-reducer, and resistors.

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 the correct heating of the passenger compartment. Repairing the VAZ-2110 stove control unit requires certain knowledge in electronics, therefore, before proceeding with the repair of the part, it is necessary to determine whether the problem is really in the electronic module itself.

To do this, you must initially dismantle the unit and install a knowingly serviceable part in its place. Take the SAUO unit from friends or at a service center to diagnose your car.

Before carrying out any work on the car that concerns the electronics and wiring, disconnect the power supply to the battery to avoid shorting or burning out the electronic components.

Then you can proceed directly to the removal of the unit, through which the functionality of the stove is coordinated. For this, the buttons on the sides of the stove are initially dismantled. The heater regulators must be switched to zero positions. Only then can the module be pulled out. This must be done very carefully, as the power plugs are connected to the rear of the unit. Once you see them, you must carefully disconnect them so as not to damage the contacts. At this, the dismantling can be considered complete.

A working unit is installed on a regular seat, and the operation of the car's heating system is checked. If the stove functions correctly with the new unit, it means that there is a malfunction in the SAUO unit itself. Otherwise, it is necessary to diagnose other elements of the heating system.

DIY VAZ-2110 heater control unit repair

If it turns out during diagnostics that the problem is in the stove control module, then it must be tried to be repaired or. Since the price of new electronic units is quite high, the right decision would be to repair the control part, especially since this requires only basic knowledge of electronics, the ability to use a tester and a soldering iron if necessary.

Before starting work, you need to disassemble the heater control unit. For this, the front cover with regulators is removed from the latches from the previously dismantled electronic module. Then a special glass cover is detached. Using a screwdriver, loosen two screws on the front of the unit and one on the back. After that, the top cover of the module can be removed; this must be done very carefully so as not to damage the contacts inside the part.

Inside the module there are electronic tracks, contacts and resistors, which are responsible for the high-quality functioning of the controllers of the car's heating system. It is necessary to inspect all contacts, electronic tracks on the board, resistors and jumpers. The board can become very hot from high operating temperatures, which will lead to the disconnection of the contacts. Particular attention should be paid to the power supply points, to clean the contacts. If there is visible damage to the electronic circuit, it is necessary to solder the damaged elements. In parallel, using a tester and an ohmmeter, the functionality of the electronic elements and resistors on the board is checked. If necessary, replace the non-working parts on the board of the SAUO module.

After troubleshooting, the heater control unit is assembled in the reverse order and installed in its original place. Next, you need to connect the battery power and check the operation of the vehicle's heating system; if necessary, the heater controller is adjusted.

Adjusting the fuser controller

The manufacturing plant provides for heating the passenger compartment to the specified temperature in fifteen minutes with a deviation of up to two degrees. Use the controller knob to set a comfortable temperature regime in the car.

To check that the stove is functioning properly, use a conventional mercury room thermometer. If, after fifteen minutes, the interior has not warmed up to the required temperature, the controller must be adjusted.

To do this, pull out the stove control module back and turn the temperature regulator first to the maximum value, then in the opposite direction. After carrying out these actions, install the unit in place and check the operation of the stove again.

In parallel, it is necessary to check the operation of the heater flaps. If there are extraneous sounds when switching temperature modes, then you need to check the condition of the dampers. If cold air comes in well, but hot air hardly comes in, then. In the absence of a normal flow of cold air with a good supply of hot air, there is a problem with the upper damper. The reason may be the deformation of the dampers under the influence of air at different temperatures. In this case, it is better to replace the standard plastic dampers with aluminum counterparts, which are more resistant to temperature extremes.

After adjusting the controller, all heater elements are installed in their original places. Assembly is carried out upside-down.

Let's sum up

Malfunctions of the VAZ-2110 stove control unit can lead to both incorrect functioning of the car's heating system and a complete failure of the stove. In the cold season, this will affect not only a comfortable stay in the car, but also a safe driving for the vehicle driver.

You can repair the stove control unit on your own, having basic knowledge of electronics, a desire to work and improve your comfort.

High-quality repairs and timely regular checks of the unit before the onset of cold weather will help you save money on services for repairing the stove in service centers and buying expensive elements of the heating system.

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