BMW 3 of the E46 series

since 1998 release

Repair and operation of the car

BMW 3 of the E46 series
+ BMW 3 Cars (E46)
+ Current leaving and service
+ Engine
- Cooling systems, heating
   + engine Cooling system
   - Heater and conditioner of air of salon
      Removal and installation of the control unit of the heater/conditioner
      Removal and installation of the fan of a heater
      Replacement of additional resistors of the fan of a heater
      Removal and installation of air deflectors
+ Power supply systems, injection and release
+ Electric equipment of the engine
+ RKPP and transmission line
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment

Heater and conditioner of air of salon

Scheme of a contour of the conditioner of air of salon

1 — the fan
2 — the evaporator
3 — a throttle
4 — service accession of low pressure
5 — service accession of a high pressure
6 — a dehumidifier
7 — the condenser
8 compressor:

and — external air for cooling of the condenser
b — warm air, is taken away in environment
with — not cooled air passing through the heater fan
d — the cooled air coming to salon
And — a high pressure (coolant in a gaseous form)
In — a high pressure (coolant liquid)
With — low pressure (coolant liquid)
D — low pressure (coolant in a gaseous form)

Heater. Models without conditioner

1 — the fan
2 — a clip
3 — additional resistors
For separate steps of the fan
4 — the driving block right
5 — the microswitch
6 — transfer for adjustment of gates
7 — a heating box
8 — a sealing frame
9 — sealing laying
10 — a fan cover
11 — the forward control panel

12 — the switch
For heating of back glass
13 — the fan switch
14 — draft
For adjustment of temperature
15 — a bracket
16 — the roller
Drive of airdistributing gates
17 — a control unit casing
18 — the screw
19 — the handle

Heater. Models with the conditioner

1 — the fan
2 — a bracket
3 — the fan regulator
4 — temperature sensor
5 — the ventilation gate drive
6 — a heater/conditioner box
7 — the ventilation gate
8 — sealing laying
9 — a fan cover
10 — a sealing frame
11 — the screw, M4 x 14

12 — a lateral cover of a box of a heater
13 — a hose drainage
For the conditioner compressor
Additional heater of the diesel engine
14 — an additional heater
15 — the holder
16 — the console
17 — the M8 x 20 screw, 24 N • m
18 — a nut
19 — a level
20 — the console

Holder of the compressor of the conditioner. Models 316i, 318i

1 — the compressor
2 — the holder
3 — a bolt, M8 x 55
4 — a bolt, M8 x 100

5 — the tension device
6 — the Torx screw, M8 x 55
7 — maple a belt

Fresh air comes to salon through an aircombined box, the air filter of ventilation of salon and a casing of the fan. Air passes through a box of a heater and is distributed via various gates on separate nozzles. Air supply is defined by number of turns of the electric motor of the fan.
Depending on the established temperature in salon fresh air can go to the heat exchanger. The heat exchanger is located in a heating box and is warmed up by hot cooling liquid. The air passing through the heat exchanger heats up as a result of washing of plates of the heat exchanger and then comes to salon. Thermal power of a heater is regulated by a consumption of cooling liquid. For this purpose the electromagnetic valve on the liquid pipeline serves.

The diesel engine
owing to higher efficiency has insignificant thermal productivity. Therefore here installation of a separate heater which if necessary in addition warms up cooling liquid is required. The additional heater is warmed with fuel from the separate fuel pump and if necessary is automatically connected.

Heating without conditioner: Temperature in salon can be established by the regulator. By means of two other regulators the number of turns of the four-stage fan of a heater is determined and distribution of air on nozzles is made.

Conditioner: Temperature in salon is established by a key on the control panel and is displayed on a digital board. According to it the electronic monitor of automatic equipment of the conditioner regulates opening of the crane of a heater depending on temperature in salon. Air temperature sensors in salon are in the control panel behind lattices for an air input. Electronic regulation allows to maintain air temperature in salon of a constant, irrespective of the speed of the car and external temperature.

At turning on of the conditioner air at first is cooled, dried up and then depending on the established value of temperature again is warmed up.

If absorption of fresh air is not allowed, for example, at poor quality of external air, the system can be switched by pressing of the corresponding key to the circulation mode. Thus in salon internal air circulates.


At inclusion of "Automatischer Umluft Control" ("Automatic control of circulation" - the special equipment) the system joins independently in the circulation mode as soon as in external air there are harmful components, for example, soot from combustion of diesel fuel. If quality of external air is again restored, the system automatically switches to consumption of external air.

Operation of the conditioner

The conditioner works as the refrigerator: the compressor set in motion from the electric motor compresses coolant in a gas phase, free from FCKW (R 134 and), and not doing harm to environment. Coolant is warmed thus and goes to the condenser. There it is cooled and liquefied. Via the broad valve coolant extends and comes to the evaporator where owing to the low pressure evaporates. As a result of expansion process the air passing through system of pipes and plates outside gives heat.

Thus, air is cooled, and the moisture containing in it turns into condensate which is taken away out of car limits.

At the working engine and the switched-on fan in salon through various openings the cooled air can be brought. Intensity of cooling depends on the established temperature and number of turns of the electric motor of the fan.

The electronic monitor is built in an element of management of the conditioner.

In the conditioner the condensate removed out of car limits is formed. It is the normal mode and does not indicate existence of any malfunctions in the car.

Repair of the conditioner is not described here. These works have to be performed in the conditions of a specialized workshop.

It is not allowed to open a contour of cooling of the conditioner as hit of liquid on skin can cause frostbite.
At casual hit of liquid on skin immediately wash out a defeat place cold water within not less than 15 min. Liquid of the conditioner has no color and a smell heavier than air. At leak of cooling liquid there is a danger of poisoning in the lower part of the car (availability of liquid is not felt).