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  
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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  
me  
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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  
Saturday, October 02, 2010 3:23:15 PMPage 23 © 2006 Mitchell Repair Information Company, LLC.  
     
        
        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  
me  
Saturday, October 02, 2010 3:23:15 PMPage 26 © 2006 Mitchell Repair Information Company, LLC.  
     
        
        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  
me  
Saturday, October 02, 2010 3:23:15 PMPage 27 © 2006 Mitchell Repair Information Company, LLC.  
     
        
        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.