Mercedes-Benz ML320. Manual — part 674

AUTOMATIC AIR CONDITIONING PUSH-BUTTON CONTROL MODULE, FUNCTION - GF83.40-P-2000GI

MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning

Fig. 69: Identifying Blower Switch, Temperature Selector Wheel, Air Distribution Switch And Interior
Air Temperature Sensor

Function

The AAC push-button control module (N22) makes it possible to make adjustments coming from the driver
such as:



air quantity, by adjusting the blower switch setting (1)



temperature by setting the temperature selector wheel (2)



air distribution, by setting the air distribution switch (3)



defrost function by pressing the defroster button (

)



recirculated air mode by pressing the recirculated air push-button (

)



automatic air distribution/blower speed by pressing the Auto



switching off the cooling by pressing the AC button (

)



activating the residual engine heat utilization system with the ignition switched off by pressing the REST
button (

)



heating the rear window by pressing the rear window heating button (

)



switching off the air distribution to the rear compartment by pressing the rear compartment air
distribution button (

)

612.963

2005GH

Residual engine heat utilization system, function

GF83.75-P-
2000GI

Automatic air conditioning system component summary,
location/purpose/design/function

GF83.40-P-
9990GI

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

The control module integrated in the AAC push-button control module (N22) looks after all system regulation
and control functions such as:



comparing preselected and actual temperatures and controlling the air temperature at the air outlets



automatic switchover from fresh air to recirculated air mode



electrical control of refrigerant compressor



controlling the auxiliary fan or the electric suction-type fan motor/ air conditioning with integrated
control

The AAC push-button control module (N22) has a diagnostic capability. Consequently, any faults which occur
are stored in the fault memory which can be read with the help of the diagnosis assistant system (DAS).

When the AAC push-button control module is replaced (N22), variant coding must be carried out using the
Diagnosis Assistant System (DAS).

The AAC push-button control module (N22) also performs the following actuations:



direct: refrigerant compressor; heating water circulation pump; PTC heater booster (OM 612 only), rear
window heater



via the CAN BUS: auxiliary fan, electric suction-type fan motor/air conditioning with integrated control,
blower control and air distribution in the rear compartment (automatic mode)



via the AC bus: blower motor; 8 stepping motors for air distribution

The following sensor signals are read in by the AAC push-button control module (N22):



direct: temperature sensor evaporator, pressure and temperature sensor refrigerant, in-car temperature
sensor, center nozzle vent air temperature sensor, footwell and rear passenger compartment, sun sensor



via the CAN BUS: Ambient temperature display temperature sensor, sensor for specified values in rear
control panel

REFRIGERANT CIRCUIT FUNCTION - GF83.40-P-2001GH

MODEL 163 up to 31.8.01 with CODE (580) Air conditioning or Tempmatic for USA

Blower switch, location/task/design/function

GF83.25-P-2100GI

Temperature selector wheel, location/task/ design/function

GF83.25-P-2102GI

Air distribution switch, location/task/design/ function

GF83.25-P-2101GI

Defroster button, location/task/function

GF83.40-P-2139GI

Recirculating air push-button, location/task/ function

GF83.40-P-2145GI

Auto button, location/task/function

GF83.40-P-2147GI

AC OFF button, location/task/function

GF83.40-P-2107GI

Rest push-button, location/task/function

GF83.40-P-2148GI

Rear passenger compartment air distribution button, location/task/function

GF83.40-P-2173GI

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Fig. 70: Identifying Refrigerant Circuit Function (Model 163 Up To 31.8.01 With Code (580) Air
Conditioning Or Tempmatic For USA)

The refrigerant compressor (1) driven by motor compresses the gaseous refrigerant, which is thereby heated up
and routed to the condenser (2).

The condenser's (2) surface withdraws the refrigerant's compression heat. When cooling down the refrigerant
liquefies.

When flowing through the fluid reservoir (3) the refrigerant is purified of any chemicals and mechanical
impurities and the water in the refrigerant is separated and collected.

The expansion valve (4) injects the cooled down and liquefied refrigerant in the evaporator (5), which is located
in the fresh air flow. Here the refrigerant is vaporized. This vaporization process then withdraws heat from the
blow-by fresh air which comes in from outside over the pipe and monolith systems with the result that it cools
down.

The humidity carried along with it is converted to condensed water which is routed to the outside. The air is
dried.

The refrigerant compressor (1) draws in the refrigerant which has turned gaseous on account of the heat
absorption and compresses it again.

When the engine is running and the blower switched on, the passenger compartment can have cool air supplied
to it by various outlet nozzles. The intensity of the cooling process depends on the previously set in-car
temperature and the blower output.

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

REFRIGERANT CIRCUIT, FUNCTION - GF83.40-P-2001GI

MODEL 163 as of 1.9.01 with code (580a) Automatic air conditioning

Auxiliary fan, location/task/function

Engines 111.977, 112.942

GF83.40-P-
2162GH

Electric fan motor/air conditioning,
location/task/function

Engines 113.942/981 and

612.963

GF83.40-P-
2151GH

Condenser position/task/function

GF83.40-P-
2152GC

Evaporator, location/purpose/design/function

GF83.40-P-
2121GC

Fluid reservoir (TAC), location/task/function

GF83.30-P-
2120GC

Expansion valve, location/task/design/function

GF83.40-P-
2123GC

Refrigerant pressure sensor, location/task/ function

GF83.40-P-
2156GH

Refrigerant compressor, location/task/design/
function

GF83.55-P-
2100GH

Air conditioning control module, location/task/
function

GF83.30-P-
2102GH

All-activity module, location/task/design/ function

GF54.21-P-
4110GH

Extended-activity module, position/task

GF54.21-P-
4106GH

Extended-activity module, location/task/design

as of 1.12.99

GF54.21-P-
4107GK

CDI control module, location/task/function

Engine 612.963

GF07.16-P-
3102IA

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me