Mercedes S-Class W-220

since 1998 release

Repair and operation of the car


Mercedes W220
+ Mercedes-Benz cars of the class S (W220)
+ Operation manual
+ Routine maintenance
+ Engine
- Cooling system and heating
   + Cooling system
   - Systems of ventilation, heating and air conditioning
      The air conditioning system - the general information and precautionary measures
      Arrangement of the basic electric elements of the air conditioning system
+ Power supply system and release
+ Engine electric equipment
+ Automatic transmission
+ Power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ Schemes of electric equipment



The air conditioning system - the general information and precautionary measures

Function chart of a contour of KV

1 — the Face cover
2 — the Broad tank
3 — the Radiator
4 — the Thermostat
5 — the Water pump
6 — the oil filter Equipped with the heat exchanger
7 — the Ventilating line
8 — the heater Heat exchanger
And — Return of cooling liquid
In — Supply of cooling liquid
With — the Ventilating line
D — the Mode of a short contour
Е — the Combined mode
F — the Ventilatory mode
M — the Motor
S — the Tank of liquid of washing of a windshield

A31m1 — the Water pump
A31y1 — the Left dual valve
A31y2 — the Right dual valve

On models with the back conditioner of air (code 528)
9 — the heater Heat exchanger
A31 1m1 — the Water pump
A31 1y1 — the Left dual valve
A31 1y2 — the Right dual valve


Management of KV on temperature

Signatures belong also to drawings below.
A1 — the Control panel
A9 — the K/V Compressor
A31 — the Block of delivery of system of heating (including the circulation pulser of a cooler both the right and left double valves)
A31/1 — the Power supply unit of the back strengthened heater
A31/1m1 — the Circulation pulser of cooling liquid
A31/1y1 — the Left double valve
A31/1y2 — the Right double valve
A32 — the Block of circulation of system of heating
B10/2 — the Sensor of temperature of the left heater
B10/3 — the Sensor of temperature of the right heater
B10/6 — the evaporator temperature Sensor
B10/09 — the Sensor of temperature of the left heater back To/in
B10/10 — the Sensor of temperature of the right heater back To/in
B10/11 — the Sensor of temperature of the evaporator back To/in
B11/4 — the Sensor of temperature of cooling liquid
B12 — the coolant pressure Sensor
B12/1 — the coolant temperature Sensor
B14 — the Sensor of external temperature
B32/2 — the Sensor of management of additional air (AAC)
K40/7 — the Forward right block of the relay and safety locks
M2/1 — Back produvny the motor
M4/3 — the Blown fan (engine/AAC)
M16/22 — the Motor of the drive of distribution of the ascending and descending air streams
N3 — the Control unit of continuous injection of fuel (CFI)
N10/6 — Forward left SAM
N10/7 — Forward right SAM
N22 — the Control unit of the button of switching off of AAS
N22/b1 — the Sensor of temperature of salon in AAC switching off button control unit

N22/4 — the Control unit back To/in
N22/5 — the Electronic control unit the step motor
N29/2 — the Regulator of a purge back To/in
N70/b1 — the Sensor of temperature of salon in the control unit of the top console
N76 — the Control unit of the fan of the engine and To/in
Y67 — the Valve of switching off of coolant back To/in
M10/3 — the Motor of the drive of the left forward window regulator
M10/4 — the Motor of the drive of the right forward window regulator
M10/5 — the Motor of the drive of the left back window regulator
M10/6 — the Motor of the drive of the right back window regulator
M12/1 — the Drive of the top hatch
N69/1 — the Control unit of the left forward door
N69/2 — the Control unit of the right forward door
N69/3 — the Control unit of the left back door
N69/4 — the Control unit of the right back door
N70 — the Control unit of the top console

Control of the KV refrigerator compressor (interpretation of designations is given above)

Control of the fan of system of cooling/KV (interpretation of designations is given above)

Management of temperature (interpretation of designations is given above)

Management of blocking of systems of comfort (interpretation of designations is given above)


The air conditioning system consists of the condenser located before a radiator of the cooling system, the evaporator close to the heat exchanger of a heater, the compressor given by a driving belt, a receiver / dehumidifier, and also various tubes connecting the listed above components. On an entrance of the evaporator the gate providing pressure difference necessary for work of system is installed.

The fan gives warm air from salon to the evaporator (a radiator analog) where heat of air is transferred to coolant. At the same time coolant evaporates and goes out of the evaporator.

Schemes of the devices and components interconnected with KV are submitted on illustrations.

The system is under pressure. Do not try to disconnect any tubes concerning the air conditioning system previously without having removed from it working liquid. Removal of liquid from system — rather difficult operation which has to be carried out at the station of service. In system there is a coolant of the R134a type. Make sure that at the station there is necessary for this purpose like coolant an equipment. Use goggles, disconnecting system tubes.


If on your car the air conditioning system is installed, when carrying out service of its any component observe the following precautionary measures:

a) The R134a coolant which is used now is much less aggressive, than the coolant of the R12 type used earlier. Nevertheless, it is very hazardous to health. Do not allow its hit in eyes or on skin — you can get burn. Though it is also not toxic, its couples can cause suffocation — do not delete it from system, being indoors. Its couple it is heavier than air therefore you are not under the car during its removal from system.
b) Do not allow contact of vapors of coolant with naked flame. At its combustion poisonous gas is emitted. The gas mixed with air in a certain proportion can become explosive. Steam inhalation through the lit cigarette can lead to tragic consequences.
c) Do not allow hit of coolant in the atmosphere. Unlike R12 coolant like R134a does not cause destruction of an ozone layer, but leads to emergence of greenhouse effect in the atmosphere.
d) In system the consolidations made of the special material intended for work with the set coolant type are used (for R134a — green color). Incidentally not to mix various types of coolants, for gas station of a certain type of coolant adapters are used a certain type.
e) The discharge of system should be carried out on HUNDRED Daimler-Benz.
f) Before carrying out any works connected with heating of any knots of the car (welding, the soldering, drying after painting), discharge system. It is also necessary to discharge system before carrying out service any of knots of the air conditioning system.