Page 3265 of 4133
Fig. 17: Identifying Rear No zzle And Two Individually-Adjustable Slatted Shutters
RECIRCULATING AIR SWITCH FUNCTION - GF83.10-P-2117-01GH
Function
Pressing the recirculating air switch ( ) actuates the fresh air/recircul ating air flap actuator motor (M39),
which opens the recirculating air flap using a mechanic al operating mechanism and simultaneously closes the
fresh air supply.
If the manual recirculating air system is active the diode illuminates in the recirculating air switch ( ).
RECIRCULATING AIR SWITCH LOCATION - GF83.10-P-2117-02GH
The recirculating air switch ( ) is in the heater control unit (S98).
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Page 3266 of 4133

Fig. 18: Identifying Recirculating Air Switch
RECIRCULATING AIR SWITCH LOCATION/TASK/DESIGN/FUNCTION - GF83.10-P-2117GH
MODEL 163 up to 31.8.01
SERIES RESISTOR GROUP, POSITION - GF83.10-P-2124-01GH
The series resistor group (R14) is at the bottom right of the heater/ evaporator housing (1) behind the bottom
section of the instrument panel at the passenger side (2).
Fig. 19: Identifying Series Resistor Group
SERIES RESISTOR ASSEMBLY FUNCTION - GF83.10-P-2124-02GH
Function
Recirculating air switch
location GF83.10-P-2117-
02GH
Recirculating air switch,
taskThe recirculating air switch ( ) is used to operate the
fresh air/recirculating air flap.
Recirculating air switch,
designThe recirculating air switch ( ) is equipped with an LED
as a malfunction indicator lamp.
Recirculating air switch
function GF83.10-P-2117-
01GH
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
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Page 3267 of 4133

The series resistor assembly (R14) is comprised of three resistors which can be interconnected, via series
connection, to form an overall resistor. Depending on the setting of the blower switch, current is guided via the
resistors assigned to the set blower level to the blower (M2). Different control voltages are therefore present at
the blower (M2), as a result of which the blower (M2) operates at different rotational speeds.
COMBINATION FILTER, LOCATION/TASK/DESIGN/FUNCTION - GF83.10-P-2128GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Fig. 20: Identifying Combination Filter
FOOTWELL FLAP ACTUATOR MOTOR, FUNCTION - GF83.10-P-2132-02GI
Pin assignment of series resistor assembly
R14Assigned
resistorBlower switch
settingBlower (M2) control
voltage
Pin 1R3Blower level 310V
Pin 2R2+R3Blower level 28V
Pin 3R1+R2+R3Blower level 14V
Pin 4NoneBlower level 412V
Combination
filter locationThe combination filter (1) is at the bottom of the automatic air conditioning box.
Combination
filter taskThe combination filter (1) removes impurities and odors from the air flowing through
the automatic air conditioning box. Fresh air and recirculating air are filtered.
Combination
filter designThe combination filter (1) consists of fleece and a large number of so-called sliver
absorbers that are evenly distributed over an air-permeable carrier mat.
Combination
filter function
The combination filter (1) filters over 80% of particles from 0.3 in size and up to
100% of 0.5 u sized particles and pollen. The sliver adsorbers also continuously
absorb odors and pollutants and release them again in extremely small concentrations
after a certain time.
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Page 3268 of 4133

Function
Rotating the air distribution switch in the AAC push-button control module (N22) actuates the footwell flap
actuator motor via the AC bus. The footwell flap actuator motor (M2/21) controls the footwell flap, which
adopts the following positions according to requirements.
Switching logic
footwell flap closed = 0%
footwell flap open = 100%
Automatic footwell flap control (Auto button engaged)
The footwell flap is opened depending on the following values
blending air flap setting
Coolant temperature
Evaporator temperature
linear up to 100 % open.
Footwell flap control via push-button control module
(Clock type switch setting of air distribution switch)
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 replacing an actuator motor an adjustment run must be performed via the Diagnosis Assistant System
(DAS), i.e. the flap OPEN and SHUT limit positions are defined and retained.
FOOTWELL FLAP ACTUATOR MOTOR, LOCATION / TASK / FUNCTION - GF83.10-P-2132GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
1 o'clock 2 o'clock 3 o'clock 4 o'clock 5 o'clock6 o'clock
17% 32% 50% 68% 85%
100%
7 o'clock 8 o'clock 9 o'clock 10 o'clock 11 o'clock
12 o'clock
66% 31%
0%
%0%0%
NOTE: All actuator motors are identical.
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Page 3269 of 4133
Fig. 21: Identifying Footwell Flap Actuator Motor
AIR INLET, LOCATION/FUNCTION - GF83.10-P-2138GC
MODEL 163, 168
AIR DUCTS, LOCATION/TASK/DESIGN - GF83.10-P-2139GH
MODEL 163
Footwell flap actuator
motor, locationThe footwell flap actuator motor (M2/15) is on the left on the
automatic air conditioning box.
Footwell flap actuator
motor, taskThe footwell flap actuator motor operates the footwell flap for
regulating the air flow to the front footwell.
Footwell flap actuator
motor, function GF83.10-P-
2132-02GI
Air inlet, locationModel 168GF83.10-P-2100-01GC
Model 163
GF83.10-P-2100-01GH
Air inlet, functionThe fresh air required for
ventilation flows through
the air inlet to the
heater/air conditioning
housing.
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Page 3270 of 4133
Design shown up to 31.08.01
Fig. 22: Identifying Air Ducts
- Design Shown Up To 31.08.01
BLOWER REGULATOR, LOCATION / TASK / FUNCTION - GF83.10-P-2141GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Air duct
locationsup to 31.08.01GF83.10-P-
2101-01GH
as of 1.09.01GF83.10-P-
2101-01GI
Air ducts
taskThe air ducts (1-5) lead the air that is required to ventilate the vehicle
from the heater/ evaporator housing to the air vents in the vehicle
interior.
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
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Page 3271 of 4133

Fig. 23: Identifying Blower Regulator
DUST FILTER, LOCATION / TASK / FUNCTION - GF83.10-P-2142GH
MODEL 163 up to 31.8.01
REAR VENTILATION, LOCATION/PURPOSE/FUNCTION - GF83.10-P-2143GC
MODEL 163, 168
Blower regulator,
locationThe blower regulator (A32n1) is below the glove compartment, to
the right of the evaporator housing.
Blower regulator,
taskThe blower regulator controls the voltage supply to the blower
motor (A32m1) depending on the current blower setting.
Blower controller
function GF83.10-P-
2103-01GI
Dust filter,
location GF83.10-P-
2104-01GH
Dust filter
taskThe dust filter filters the fresh air and recirculating air flowing through the
heater/ evaporator housing.
Dust filter,
functionThe dust filter element consists of fleece, which cleans the air flowing
through. The dust filter filters over 80 % of particles from 0.3 m in size and
up to 100 % of 0.5 pm sized particles and pollen.
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
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Page 3272 of 4133

DEFROSTER NOZZLE, LOCATION/PURPOSE/FUNCTION - GF83.10-P-2144GC
MODEL 163, 168
FRONT FOOTWELL AIR OUTLET, LOCATION/PURPOSE/FUNCTION - GF83.10-P-2145GC
MODEL 163, 168
REAR FOOTWELL AIR VENT, LOCATION/TASK/FUNCTION - GF83.10-P-2146GC
MODEL 163 up to 31.8.01, 168
Rear ventilation,
locationModel 168GF83.10-P-2105-
02GC
Model 163GF83.10-P-2105-
02GH
Rear ventilation,
purposeThe air flowing through the vehicle passenger compartment exits
the vehicle through the rear vents.
Rear ventilation,
function GF83.10-P-2105-
01GC
Defroster nozzle,
locationModel 168GF83.10-P-2106-
01GC
Model 163GF83.10-P-2106-
01GH
Defroster nozzle,
purposeThe defroster nozzles serve for ventilation and keeping the
windshield and side windows from fogging up.
Defroster nozzle,
function
The air supply to the windshield defroster nozzles can be opened
and closed with the air distribution switch.
Separate adjustment is not possible. Blended air exits from the
defroster nozzles.
Front footwell air outlet,
locationModel 168GF83.10-P-2109-
02GC
Model 163GF83.10-P-2109-
02GH
Front footwell air outlet,
purposeThe front footwell air outlet serves for ventilation of the
left and right front footwell.
Front footwell air outlet,
function GF83.10-P-2109-
01GC
Rear footwell air vent
locationModel 168GF83.10-P-2110-
02GC
Model 163GF83.10-P-2110-
02GH
2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 28 © 2006 Mitchell Repair Information Company, LLC.