Mercedes-Benz ML320. Manual — part 675

Fig. 71: Identifying Refrigerant Circuit, Function (Model 163 As Of 1.9.01 With Code (580A) Automatic
Air Conditioning)

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

The refrigerant's compression heat is then withdrawn on the surface of the condenser. While cooling down, the
refrigerant liquefies.

When the refrigerant flows through the fluid reservoir it is cleansed of any chemical and mechanical impurities.
The water contained in the refrigerant is separated and collected.

The expansion valve sprays the cooled and liquefied refrigerant into the evaporator, which is located in the
fresh-air flow. Here the refrigerant is vaporized. Through this evaporation process heat is extracted from the
fresh air flowing past from outside over the tube and fin system so that air cools down.

The air humidity carried along is converted to condensed water, which escapes into the open. The air dries out.

The refrigerant compressor aspirates the refrigerant which has turned gaseous on account of the heat absorption
and then compresses it yet again.

When the engine is running and the blower switched on, the interior can be supplied with cooled air through the
various air outlets. Cooling intensity is dependent upon the preset in-car temperature and blower setting.

Engine 111.977, 112.942, 112.970

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

REAR VENTILATION CONTROL PANEL, FUNCTION - GF83.40-P-2007GI

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

N72/2s3 Rear ventilation control panel

Auto button

Air distribution button

Blower button

Auxiliary fan, location/purpose/function

with code 580 up to 31.08.01
Engine 112.942, 112.970 with
code 580a as of 01.09.01

GF83.40-P-
2162GH

Engine and AC electric suction fan with integrated
control, location/purpose/function

Engine 113.942 with code 580a up
to 31.08.01
Engine 113.981, 113.965, 612.963,
628.963 with code 580a as of
01.09.01

GF83.40-P-
2172GI

Condenser, location/purpose/function

GF83.40-P-
2152GC

Evaporator location/purpose/design/function

GF83.40-P-
2121GC

Fluid reservoir, location/purpose/function

GF83.40-P-
2153GI

Expansion valve, location/purpose/design/ function

GF83.40-P-
2123GC

Refrigerant pressure and temperature sensor,
location/purpose/function

GF83.40-P-
2171GI

Refrigerant compressor, location/purpose/
design/function

GF83.55-P-
2100P

Control valve, location/purpose/function

GF83.55-P-
2102P

Belt pulley, location/purpose/design/function

GF83.55-P-
2103P

Pressure relief valve, location/purpose/function

GF83.55-P-
2104P

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Fig. 72: Identifying Rear Ventilation Control Panel

The rear ventilation control panel (N72/2s3) enables specific settings to be made for the rear compartment
ventilation system.

The following possibilities are available:



Setting air quantity by pressing the blower button (

)



Air distribution by pressing the air distribution button (

)



Automatic air distribution/blower speed by pressing the Auto button (

) (Control through AAC push-

button control module (N22))

BLOWER BUTTON, FUNCTION - GF83.40-P-2100-01GI

The blower button (

) switches a control voltage of 0 - 6 V through to the rear compartment blower control

via the rear ventilation control panel (N72/2s3).

By using several blower steps it is possible to regulate the blower speed between 0-100 %.

The automatic blower function can be set by pressing the Auto button, whereby control is assumed by the AAC
push-button control module (N22).

AIR DISTRIBUTION BUTTON FUNCTION - GF83.40-P-2101-01GI

Function

By pressing the air distribution button (

) the rear passenger compartment air distributor flap actuator

motor is regulated by the rear ventilation control panel. The rear passenger compartment air distributor flap
actuator motor drives the rear passenger compartment air distributor flap, which can route the air into two
directions.

Blower button position/task/function

GF83.40-P-2144GI

Air distribution button, location/task/function

GF83.40-P-2159GI

Auto button, location/task/function

GF83.40-P-2147GJ

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Air distribution button (

) = air ducting to rear compartment nozzle

Air distribution button (

) = air ducting to the air outlets in the rear footwell

The automatic air distribution function can be set by pressing the Auto button, whereby control is assumed by
the AAC push-button control module (N22).

RECIRCULATING AIR PUSH-BUTTON, FUNCTION - GF83.40-P-2102-01GI

Function

A brief actuation (< 1.5 s) of the recirculating air push-button (

) energizes the actuator motor for the fresh

air/recirculated air flap, which activates the fresh air/recirculated air flap and thus closes the fresh air duct and
opens the recirculation duct, in order to enable the air supply from the passenger compartment. The function
LED illuminates during recirculation mode.

Recirculated air convenience closing function

If the recirculating air push-button (

) is pressed for longer than > 2 s, then alongside the recirculation

function, all open windows and the sliding and tilting roof are automatically closed (window and sliding/
tilting roof must have been normalized ). The function LED illuminates during recirculation mode. In order to
prevent any current peaks the sliding/tilting sunroof and power windows are actuated successively.

If the push-button is pressed again for > 2 s, the windows and the sliding/tilting sunroof return to the previously
stored position and the fresh air/recirculated air flap moves to the fresh air position (LED off).

The convenience closing function can only be started if the recirculating LED is not illuminated.

Each window, which has been manually opened during the recirculation phase, remains in this position if the
recirculating function is cleared: all other windows move to the stored positions. The position of the
sliding/tilting sunroof prior to the start of the closing operation and that of the side windows is stored in the
memory. The windows and the sliding/tilting sunroof which have been closed by the convenience closing
function, remain closed if the recirculation push-button was only pressed briefly (t < 1.5 s). In this case, only the
fresh air/recirculated air flap is moved to the fresh-air position. The stored positions are cleared when the
ignition is switched off.

AUTOMATIC AIR CONDITIONING BOX FUNCTION - GF83.40-P-2105-02GI

Operating condition: Air ducting under heater operation

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me