1997 MERCEDES-BENZ ML320 air condition

Fig. 62: Identifying Evaporator Housing Function - Operating Condition Blend Air Ducting
(Warm/Cold) Closed-Loop Operation
Operating condition: Blend air (warm/cold) Function
In the blend air operating status, the fresh air (A) is drawn in by the blower (5) into the evaporator housing and
routed through the dust filter (3). The air purified by the dust filter (3) is then routed through the evaporator (2)
and dried there. Some of the dried, cold and cleaned air (B) is routed through the heat exchanger (1) and some is
routed around the heat exchanger (1). This air conduction is controlled via the central setting of the blending air
flaps (6).
The air (B), which has been dried, cooled and cleaned by the heat exchanger (1) is heated up again. After
passing through the blending air flaps (6) this heated air (C) is mixed up to form blend air (D) with the dried,
cooled and cleaned air, which was routed around the heat exchanger (1). This blend air (D) is then routed via
the air outlets (E, F, M and S) into the passenger compartment. The recirculated air flap (4) is closed.
Operating condition: Air ducting "recirculation air" in cooling mode

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 71 © 2006 Mitchell Repair Information Company, LLC.

Fig. 63: Identifying Evaporator Housing Function - Operating Condition Air Ducting Recirculation Air
In Cooling Mode)
Operating condition: Cooling down "recirculation air" Function
In the cooling mode with recirculating air the blower (5) draws the recirculated air (A) from the passenger
compartment over the opened recirculated air flaps (4) into the evaporator housing and routes it through the dust
cleaner (3). The air purified by the dust filter (3) is then routed through the evaporator (2) and dried there. The
fresh air (B), which has been dried, cooled and cleaned, is subsequently routed around the heat exchanger (1).
This air conduction is controlled via the setting of the blending air flap (6).
The dried, cooled and cleaned air (B) is routed directly into the passenger compartment via the air outlets (E, F,
M and S). The supply of fresh air is cut off by the recirculated air flap (4).
EVAPORATOR HOUSING, TASK - GF83.30-P-2104-04GH
The evaporator housing houses the following components:
Air ducting flaps
Dust filter
Blower
Series resistor group
Evaporator
Heating system heat exchanger
Expansion valve

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 72 © 2006 Mitchell Repair Information Company, LLC.

Blending air flap actuator
Recirculated air flap actuator motor
Electric heater booster (for engine 612.963 only) and therefore forms a complete unit.
The evaporator housing distributes the air that is required to ventilate the vehicle to the relevant air ducts and
vents depending on the required interior temperature.
The air ducting depends on various operating conditions such as:
Heating mode
Cooling mode
Blend air mode (cold/warm)
Cooling air mode with recirculated air
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTOR, POSITION - GF83.30-P-2105-01GC
The fresh air/recirculated air flap actuator motor (M16/7) is located on the A/C housing between the two fresh
air/recirculated air flaps.
Fig. 64: Identifying Fresh Air/Recirculated Air Flap Actuator Motor

FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTOR, POSITION - GF83.30-P-2105-01GH
The fresh air/recirculated air flap actuator motor (M39) is located at the side of the air intake housing on the
evaporator housin
g.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 73 © 2006 Mitchell Repair Information Company, LLC.

Fig. 65: Identifying Fresh Air/Recirc ulated Air Flap Actuator Motor
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTO R, FUNCTION - GF83.30-P-2105-02GH
Function
The fresh air/recirculated air flap actuator motor (M39) is controlled via the recirculation air switch ( ) and
when the temperature selector switch is set to max. cooling output in the control module (S98).
Recirculated air mode (100 % recirculated air)
In the recirculated air mode the supply of fresh air is closed by the fresh air/recirculated air flap actuator motor
(M39) and simultaneously the recirculated air supply opened without any time limit.
Fresh air mode (100 % fresh air)
In the fresh air mode the supply of fresh air is opened by th e fresh air/ recirculated air flap actuator motor (M39)
and simultaneously the recirculated air supply closed without any time limit.
Auxiliary function at air conditioning (TAC)
When, in the cooling mode, the temperat ure selector wheel is set to max. cooling (position indented blue) then
at the same time the fres h air/recirculated air flap actuator moto r (M39) is controlled and switched to
recirculation air wi thout time limit.
FRESH AIR/RECIRCUL ATED AIR FLAP ACTUATOR, FU NCTION - GF83.30-P-2105-02GI
Function
Pressing the recirculating air push- button ( ) on the AAC push-button control module (N22) actuates the
fresh air/recirculated air flap actuator motor (M2/5) via the air conditioner bus.
In recirculation mode, the recircul ation air supply is closed off by th e fresh air/recirculated air flap.
In fresh air mode, the fresh air supply is ope ned by the fresh air/ recirculated air flap.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 74 © 2006 Mitchell Repair Information Company, LLC.

Control of fresh air/recirculated air flap via the AAC push-button control module (N22)
When the recirculating air push-button is pressed ( ) on the AAC push-button control module the system is
switched by means of the fresh air/recirculated air flap actuator motor straight to 100 % recirculation air. This is
displayed by the function LED.
If a problem exists, it is possible to retrieve and verify the defined end positions by means of the diagnosis
assistant system (DAS) (valuation trip).
After replacement of an actuator motor it is necessary for an adjustment run to be performed using the diagnosis
assistant system (DAS), i.e. the end positions flap OPEN and SHUT are defined and retained.
AIR CONDITIONING FLUID RESERVOIR, LOCATION - GF83.30-P-2106-01GH
The fluid reservoir (6) is located in the left front of the engine compartment, next to the condenser.
Fig. 66: Identifying Air Conditioning Fluid Reservoir And Associated Components

AIR CONDITIONING FLUID RESERVOIR, FUNCTION - GF83.30-P-2106-02GC
Function
NOTE: The recirculated air function can be terminated after a set time-out in
accordance with country specifications.
NOTE: All actuators are identical.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 75 © 2006 Mitchell Repair Information Company, LLC.

The liquefied refrigerant is routed under pressure into the fluid reservoir and flows through a stainless steel
meshing to the filter block. The pores in the filter block are matched precisely to the refrigerant's molecular size.
Thus the refrigerant can flow through the filter block.
All other matter, primarily water, is held back by this molecular filter and deposited. The cleaned refrigerant
flows over a rising pipe to the expansion valve.
Whenever the system is opened, the fluid reservoir should be replaced because of the water which has
collected there in the meantime.
ALL-ACTIVITY MODULE, LOCATION - GF83.30-P-2108-02GH
The all-activity module (AAM) (N10) is located in the left-hand side of the engine compartment. It is plugged
on from below to the fuse and relay module (F1).
Fig. 67: Identifying All
-Activity Module And Relay Module
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR, LOCATION/TASK/FUNCTION - GF83.30-P-2116GC
MODELS 163 up to 31.8.01, 168 up to 28.2.01 with CODE (580) Air conditioning or Tempmatic for USA
MODEL 163 as of 1.9.01 with code (580a) Automatic air conditioning
Shown on model 163 as of 1.09.01

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 76 © 2006 Mitchell Repair Information Company, LLC.

Fig. 68: Identifying Fresh Air/Recirculated Air Flap Actuator - Shown On Model 163 As Of 1.09.01
EVAPORATOR HOUSING, LOCATION/TASK/FUNCTION - GF83.30-P-2119GH
MODEL 163 up to 31.8.01 with CODE (580) Air conditioning or Tempmatic for USA
Fresh air/recirculated air
flap actuator, positionThe fresh air/recirculated air flap actuator (M2/5) is
located on the side of the air inlet duct of the air
conditioner housing.

Model 168GF83.30-P-
2105-01GC
Model 163, up to 31.08.01GF83.30-P-
2105-01GH
Fresh air/recirculated air
flap actuator, taskThe fresh air/recirculated air flap actuator serves to cut off
the supply of fresh air when required.
Fresh air/recirculated air
flap actuator, functionModel 168GF83.30-P-
2105-02GC
Model 163, up to 31.08.01GF83.30-P-
2105-02GH
Model 163 as of 1.09.01GF83.30-P-
2105-02GI
Evaporator housing,
location GF83.30-P-2104-
01GH
GF83.30-P-2104-

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 77 © 2006 Mitchell Repair Information Company, LLC.

AIR CONDITIONING FLUID RESERVOIR, LOCATION/TASK/FUNCTION - GF83.30-P-2120GC
MODELS 163 up to 31.8.01
168 up to with code (580) Air conditioning or Tempmatic for USA
OVERVIEW OF AIR CONDITIONING (TAC) SYSTEM COMPONENTS, LOCATION/PURPOSE/DESIGN/FUNCTION -
GF83.30-P-9999GI
MODEL 163 up to 31.8.01 with CODE (580a) Automatic air conditioning
Evaporator housing, task 04GH
Evaporator housing,
function GF83.30-P-2104-
02GH
At maximum heating mode in vehicles with engine
612.963 onlyGF83.30-P-2104-
02GK
Fluid reservoir (TAC),
locationModel 168GF83.30-P-2106-
01GC
Model 163GF83.30-P-2106-
01GH
Fluid reservoir (TAC),
task
Filtering chemical and mechanical impurities out
of the refrigerant
Volume accumulator for refrigerant
Draining of refrigerant

Fluid reservoir (TAC),
function GF83.30-P-2106-
02GC
Air inlet, location/function GF83.10-P-
2138GC
Air ducts, location/purpose/design GF83.10-P-
2139GH
Blower, location/purpose/design/function GF83.10-P-
2102GC
Series resistor group, location/purpose/function GF83.10-P-
2161GC
Dust filter, location/purpose/function GF83.10-P-
2142GH
Rear vent, location/purpose/function GF83.10-P-
2143GC
Defroster vent, location/purpose/function GF83.10-P-
2144GC
Center nozzle, location/purpose/function GF83.10-P-
2149GC

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 78 © 2006 Mitchell Repair Information Company, LLC.