Audi A3

since 1997 of release

Repair and car operation

Audi A3
+ Maintenance instruction
+ Current leaving and service
+ Engine
- Systems of cooling, heating
   + System of cooling of the engine
   - Systems of ventilation, heating and air conditioning
      General information and security measures
      Removal and installation of air deflectors
      Removal and installation of a nozzle of the region of feet
      Removal and drive installation lamp heater/replacement
      Removal and installation of cables of a drive of management of a heater
      Removal and installation of the fan of fresh air
      Removal and installation of the additional resistor
      Removal and compressor installation
      Conditioner diagnostics on codes on the display of the block of its management
+ the Power supply system and production of the fulfilled gases
+ engine Electric equipment
+ Manual box of gear shifting
+ Automatic transmission and models with a full drive
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Elektroskhema


Systems of ventilation, heating and air conditioning

General information and security measures


Heater and air conditioner

1–heater drive
2–switch of a zaslonka of fresh and ventilating air
The switch is rigidly connected with a drive of a heater and cannot separately be replaced.
3–nozzle of the region of feet
4–heating channel of a back part of salon
5–connecting element
6–nozzle of the region of feet
7–heater casing
8–heat exchanger
9–top air-conducting channel
10-additional resistor of the fan
11-the driving motor of a zaslonka fresh / circulating air


Illumination of the switch is carried out by a light guide, there is only one filament lamp. For replacement of a lamp remove the fan switch. H · m at take out from the boss flat-nose pliers. Since the middle of 1997 of release replacement by a light-emitting diode (LED) is made. The last is not replaced.

Components of system of heating, ventilation and the air conditionings located in salon of the car

1–nozzles of lateral glasses
3–nozzle of defrosting of glasses
4–governing bodies hot and fresh air
6–dashboard cross-piece
7–antidust filter of air of salon
8–electric motor
Fresh air / ventilating zaslonka
9–fan of fresh air
10-additional resistor
With a thermal safety lock
11-heating device
12-central peak
13-a nozzle of supply of air to the region of feet
14-forward channel
16-connecting element
17-draft of a drive of a heater
18-heat exchanger
19-joint consolidation heat exchanger/partition of an impellent compartment
20-a pro-rate for snuffled defrosting of glasses

The heater case with elements of system of heating and salon ventilation

1–heat exchanger
After removal cooling liquid should be replaced completely.
It is required in that case when lock pads of the heat exchanger are broken.
3–air distributor casing
It is not necessary to assort.
4–electric motor of a zaslonka fresh air/circulation
6–casing of fresh air
7–cover of a casing of fresh air
9–additional resistor
With an overheat safety lock.
11-lever of the central zaslonka
12-lever of a temperature zaslonka
14-consolidation heat exchanger/partition of an impellent compartment
Consolidation has a label on a face surface. It is necessary to establish consolidation so that the meta coincided with H · m a kirovka on the basis

Scheme of central air of air of salon

2–sensor of number of turns of the compressor
3–electromagnetic H · m уфта
4–stopper of removal of H · m сла
5–safety valve
6–a connecting element with the valve
7–switch of a high pressure
For the conditioner and electromagnetic H · m уфты
With consolidation, surely it should be fixed.
9–service accession
At the condenser.
11-carving connection in the pipeline of cooling liquid
It is built in connection–11–.
14-the switch of a low pressure \contour of cooling liquid
15-a connecting element with the valve
16-capacity for collecting
HD – the party of a high pressure
ND – the party of low pressure

The placement scheme in an impellent compartment of components of systems of heating and air conditioning

1–dust removal filter
2–fairing cover
3–drainage valve of the evaporator
4–sockets of the heat exchanger of a heater
5–a zaslonka of switching of modes of supply of air (fresh air / the closed circulation) (N63)
6–management of functioning of the fan of system of cooling (J293)
7–vacuum tank
8–vacuum hose
9–thermosensitive switch of the conditioner of air
11-reduktsionny valve
12-H · m уфта couplings of the conditioner of air (N25)
13-sensor switch of temperature of air (F38)
14-the pressure sensor switch in central air of air (F129)
15-receiver dehumidifier
16-observation port
17-service valves of a low and high pressure
18-broad valve

General information and security measures

The air submitted by system of ventilation to salon of the car through the filter, can be warmed up or cooled depending on a choice of the driver and passengers. The heater or the conditioner settle down in a passenger compartment in the case under the dashboard. All stream of air submitted to salon goes for heating or cooling through the same casing. The temperature and speed of a stream of air is regulated by means of governing bodies located on the control panel.

Heat allocated at operation of the engine, is transferred by cooling liquid to the radiator of a heater located in salon. The brought stream of air from system of ventilation passes through a radiator and heats up heat of cooling liquid of the engine proceeding in a radiator. Extent of heating is regulated by means of mixing in a certain ratio of cold and hot air by means of a mixing zaslonka.

The conditioner in a mode of cooling deletes excessive heat and moisture from salon according to the basic physical principles. The coolant, free from FCKW (R 134 and), and not putting harm to the environment, circulating in the form of liquid in that part of system where the high pressure is supported, evaporates and turns into gas on a site of low pressure. At expansion of gas there is a cooling, being accompanied heat selection from the air submitted by the fan to passenger salon and fall of its temperature. Further in process of passing via the condenser the coolant gives absorbed heat to air. The cycle of selection of heat proceeds infinitely long in process of coolant circulation on the closed contour. From the air submitted to salon, there is a moisture removal owing to condensation on the evaporator of the refrigerating chamber.

The conditioner automatically supports the established value salon temperature to constants.

The climatic Climatronic installation, unlike the ordinary conditioner, in addition to temperature automatically regulates quantity and air distribution. Regulation of amount of air occurs smoothly by means of change of number of turns of the fan depending on a difference of temperatures between the established value of temperature and salon temperature.

Climatronic has in addition solar sensor which registers sunlight. It is located in the dashboard center under a windscreen. At especially high sunlight the solar sensor automatically influences through an electronic control system number of turns of the fan and thus on the amount of air submitted to salon. The established value of temperature in salon is corrected according to sunlight.

The compressor, is actuated by the electric motor.

The electronic monitor is built in the conditioner control unit. At manual installation of number of turns of the fan below H · нимума the system of the heating/conditioner is switched off by m.

The malfunctions which have arisen in a monitor or sensors and executive bodies, register in memory of malfunctions of a monitor. The special device is applied to reading of codes of malfunctions.

Central air of air represents potential danger. At its service observance of certain rules is required. Performance of the majority of operations on repair and service of central air needs the special equipment and certain skills of work.

Ventilation of a body is provided with a way of formation of a through stream of air. Fresh air gets in the car through an air inlet located before a windscreen. The stream of air comes to light via the final channels located under a rear bumper.

The size of a stream of air is regulated by the four-high-speed fan.

The system of heating of air of mixing type is intended for fast response to change of air temperature in salon and reduction of a pulsation of temperature of warmed-up air. Cooling liquid of system of cooling of the engine constantly circulates in a radiator of a heater and the stream of cooling liquid is not regulated. An adjustable factor is air temperature which changes the mixing zaslonka defining amount of air, a heater passing through a radiator before its hit in car salon.

For a hit exception in salon of the car of external air there is an air circulation mode.

Security measures at service of the air conditioner

Central air should be served by exclusively prepared technicians trained in safe working methods with use of the appropriate equipment with observance of rules of depressurization, acquainted with receptions of collecting and order of storage of an automobile coolant.

Do not allow contact of a coolant to skin.

At work near central air put on goggles.

At coolant hit on skin or eyes do not pound the struck place. Immediately wash out cold water during not less than 15 H · m нут. Immediately address to the doctor or in medical institution. Self-treatment is not allowed.

The coolant is stored in a new cylinder under pressure. Store a cylinder at temperature not above 50°С. Take the measures excluding falling of a cylinder from height or other situations which can lead to its damage.

Works should be carried out in well aired room. The coolant quickly evaporates, leads to reduction of access of oxygen and the complicated breath.

The gaseous coolant is heavier some air and rather quickly should gather below, for example, under the car.
At combustion of a coolant poisonous gas is formed. Store a coolant far from open sources of fire. Do not smoke. When using an ardent techeiskatel avoid smoke inhalation.

At carrying out welding works near central air to influence of high temperature or an open flame. The overheat can lead to pressure increase in system and to ignition.

Condenser or evaporator cleaning by means of water vapor is not allowed. It is necessary to use only cold water or the compressed air.

For increase in air exchange the 4-step fan of fresh air serves. That the fan worked at separate steps with various speed, resistors turn on. Resistors are in a connecting payment on the fan. In the presence of malfunctions the connecting payment is replaced in a set.

If fresh air does not be sucked in, for example, at bad external air, the pressing of a key of circulating ventilation makes switching on air circulation. Thus air circulates only in salon. The switch displaces a zaslonka, influencing not the small electric motor.


If «The mode of defrosting of a windscreen» joins, i.e. the switch of the distributor of air is established in final situation above, the mode of circulation is impossible.
The A3 car can be equipped also with the conditioner.
Conditioner repair here is not described. These works should be carried out in the conditions of specialized H · by m of the stersky.
It is not necessary to open a contour of cooling of the conditioner as liquid hit on skin can cause frostbite.
At casual hit of liquid on skin immediately wash out a place of defeat by cold water during not less than 15 H · m of N. Cooling liquid has no color and a smell, and also it is heavier some air. At leakages of cooling liquid there is a danger of poisoning around the bottom or in the lower part of the car (availability of liquid is not felt).
At casual hit of liquid on skin immediately wash out a place of defeat by cold water during not less than 15 H · m of N. Cooling liquid has no color and a smell, and also it is heavier some air. At leakages of cooling liquid there is a danger of poisoning around the bottom or in the lower part of the car (availability of liquid is not felt).