Mercedes-Benz ML320. Service 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The refrigerant's compression heat is then withdrawn on the surface of the condenser.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