Mercedes-Benz ML320. Manual — part 673

Lateral nozzle, location/purpose/function

GF83.10-P-
2150GC

Front footwell air outlet, location/purpose/ function

GF83.10-P-
2145GC

Rear footwell air outlet, location/purpose/ function

GF83.10-P-
2146GC

Heating system heat exchanger, location/
purpose/function

GF83.20-P-
2108GC

Fresh air/recirculation flap, location/purpose/ function

GF83.20-P-
2111GC

Fresh air/recirculation flap actuator, location/
purpose/function

GF83.30-P-
2116GC

Blower switch, location/purpose/design/function

GF83.25-P-
2100GC

Air distribution switch, location/purpose/design/
function

GF83.25-P-
2101GH

Temperature selector wheel, location/purpose/
design/function

GF83.25-P-
2102GC

Air recirculation switch, location/purpose/
design/function

GF83.10-P-
2117GH

AC button, location/purpose/function

GF83.30-P-
2103GH

AC control module, location/purpose/function

GF83.30-P-
2102GH

All-activity module, location/purpose/function

GF54.21-P-
4110GH

A/C housing, location/purpose/function

GF83.30-P-
2119GH

Auxiliary fan, location/purpose/function

ENGINE 111.977, 112.942

GF83.40-P-
2162GH

Electric fan motor/air conditioning system,
location/purpose/function

Engine 113.942, 113.981 and
612.963, 628.963

GF83.40-P-
2151GH

Condenser, location/purpose/function

GF83.40-P-
2152GC

Evaporator location/purpose/design/function

GF83.40-P-
2121GC

Fluid reservoir (TAC), location/purpose/function

GF83.30-P-
2120GC

Expansion valve, location/purpose/design/ function

GF83.40-P-
2123GC

Refrigerant pressure sensor, location/purpose/ function

GF83.40-P-
2156GH

Refrigerant compressor, location/purpose/
design/function

GF83.55-P-
2100GH

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

AUTOMATIC AIR CONDITIONING (AAC), FUNCTION - GF83.40-P-0001GI

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

Function

The automatic air conditioning (AAC) is equipped with an electronically regulated cooling, heating and
ventilating system and can be summed up by the following list of subfunctions.



Ventilation

The ventilation ensures that there is a sufficient supply of air within the passenger compartment.
Ventilation is achieved with the support of the blower during normal operation, when vehicle is standing
or to increase the air flow. The air is distributed in the passenger compartment using air distribution flaps.



Automatic air conditioning temperature control

The desired temperature is reached or held constant by cooling or heating the air. Precise temperature
control can be achieved by reading in the various temperature sensors.



Residual engine heat utilization

Electromagnetic clutch, location/purpose/
design/function

GF83.55-P-
2101GH

In-car temperature sensor, location/purpose/ function

with intake jet nozzle up to
30.11.99

GF83.57-P-
2115GH

In-car temperature sensor with ventilation blower,
location/purpose/function

as of 1.12.99

GF83.57-P-
2107GH

Ice-up protection temperature sensor, location/
purpose/function

GF83.57-P-
2113GH

Blending air flap actuator, location/purpose/ function

GF83.57-P-
2112GC

Outside temperature sensor, location/purpose/ function

as of 1.12.99

GF83.57-P-
2110GH

Electric heater booster, location/purpose/
design/function

Engines 612.963 and 628.963

GF83.70-P-
4054GH

Temperature regulator microswitch, location/
purpose/function

Engine 612.963

GF83.70-P-
4055GH

Extended activity module, location/purpose

GF54.21-P-
4106GH

Extended activity module, location/purpose/ design

as of 1.12.99

GF54.21-P-
4107GK

CDI control module, location/purpose/function

Engine 612.963

GF07.16-P-
3102IA

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

The residual engine heat utilization system allows the vehicle to be heated even when the ignition is
switched OFF. To do so the system utilizes the residual heat from the engine and guides it via the
blower into the passenger compartment. The heating water circulation pump ensures that the
coolant is properly circulated.



Automatic air conditioning push-button control module

The automatic air conditioning can be operated by the driver using various tip switches. Apart from this
the push-button control module reads in different sensor signals, processes them and controls components
in the automatic air conditioning.



Rear ventilation control panel

The operator can intervene in the automatic regulation of the rear ventilation through the automatic air
conditioning by using the rear ventilation control panel and adjust it accordingly to suit needs at any
given time. With the aid of the air distribution switch and blower switch the operator can accommodate
his/her own wishes. The correspondingly altered function is then no longer regulated by the automatic air
conditioning.

By pressing the automatic control button the manually initiated settings can be reset and thus regulated
again by the automatic air conditioning.

Regulation of the air quantity and air distribution ensues thus solely by way of the automatic air
conditioning push-button control module.



Heater circuit

Coolant is heated by the engine. Subsequently, the heated coolant is then routed through the heat exchanger,
where the heat is dissipated to the air in the passenger compartment. The heater return line, in which the heating
water circulation pump is located, takes the coolant back to the coolant pump.

The heating water circulation pump ensures that the coolant is properly circulated.

The coolant flows through the heat exchanger permanently.

Depending upon the desired in-car temperature, regulation is conducted over the blending air flaps, which are
operated by the blending air flap actuator motor.

Heater operation with heater booster in vehicles with OM 612.963

In vehicles equipped with direct-injection diesel engines, an electrical heater booster is additionally installed in
the evaporator housing downstream of the heat exchanger, in order to compensate the heater output deficit
which occurs in the case of certain operating conditions.

The 3 heating elements in the heater booster are supplied with current, as a result of which they are heated and
start to glow. As a result of the structural conditions, it is ensured that the drawn in fresh air flows directly past
the electric heater booster, and is therefore heated.

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me



Refrigerant circuit

The refrigerant compressor serves to compresses the gaseous refrigerant which heats up during the process, is
then routed into the condenser and thus cooled down. After purification in the fluid reservoir the liquid
refrigerant is injected into the evaporator. The refrigerant is vaporized and cools down. The refrigerant
compressor intakes the refrigerant again which has turned gaseous through the heat absorption process.

TABLE OF CONTENTS, AUTOMATIC AIR CONDITIONING (AAC) FUNCTION DESCRIPTION - GF83.40-P-0999GI

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

Ventilation, function

GF83.10-P-2000GI

Heater circuit function

GF83.20-P-2003GH

Automatic air conditioning push-button control module, function

GF83.40-P-2000GI

Rear ventilation control panel, function

GF83.40-P-2007GI

Refrigerant circuit function

GF83.40-P-2001GI

Temperature control, function

GF83.57-P-2000GI

Heater booster (ZUH), function

GF83.70-P-0005GH

Residual engine heat utilization system, function

GF83.75-P-2000GI

Automatic air conditioning (AAC), function

GF83.40-P-
0001GI

Ventilation system function

GF83.10-P-
2000GI

Heater circuit function

GF83.20-P-
2003GH

Automatic air conditioning push-button control module, function

GF83.40-P-
2000GI

Rear ventilation control panel, function

GF83.40-P-
2007GI

Refrigerant circuit function

GF83.40-P-
2001GI

Temperature control, function

GF83.57-P-
2000GI

Heater booster (ZUH), function

Engine

612.963

GF83.70-P-
0005GH

Start heater operation, function

Engine

612.963

GF83.70-P-
2000GH

End heater operation, function

Engine

612.963

GF83.70-P-
2002GH

Regulate heater operation, function

Engine

612.963

GF83.70-P-
2004GH

Cancel heater operation, function

Engine

GF83.70-P-

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me