Mercedes-Benz ML320. Manual - part 689

The mechanical flaps are regulated by a linkage to the blending air flap actuator motor (M16/8). The flaps open 
or close the passage of air through the heating system heat exchanger in order to mix heated air with cooled air 
in the correct proportion necessary to achieve the desired in-car temperature. 

The set point flap angle of the blending air flaps is determined by the air conditioning control module as a 
function of the following information: 



set point temperature selected at the temperature selector wheel  



in-car temperature measured at the in-car temperature sensor (B10/4)  

BLENDING AIR FLAP MOTOR FUNCTION - GF83.57-P-2105-02GI 

Function  

The blending air flap actuator motor (M2/6) is actuated via the AC bus and as a function of the position of the 
temperature selector wheel in the AAC push-button control module (N22) and the actual in-car temperature. 

The mechanical flaps are regulated by a linkage to the blending air flap actuator motor (M2/6). The flaps open 
or close the passage of air through the heating system heat exchanger in order to mix heated air with cooled air 
in the correct proportion necessary to achieve the desired in-car temperature. 

The set point flap angle of the blending air flaps is determined by the AAC push-button control module (N22) 
as a function of the following information: 



set point temperature selected at the temperature selector wheel  



in-car temperature measured at the in-car temperature sensor (N22b1)  



temperatures of the air stream measured at the center nozzle air stream temperature sensors, footwell 
forward and rear (B10/24, B10/25 and B10/7)  



outside temperature measured by the outside temperature indicator temperature sensor (B14)  

All actuators are identical. 

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 an actuator motor has been replaced, an adjustment run must be performed via the Diagnosis Assistant 
System (DAS), i.e. the end positions flap OPEN and SHUT are defined and retained. 

ICING PROTECTION TEMPERATURE SENSOR, LOCATION - GF83.57-P-2106-01GH 

The icing protection temperature sensor (R35) is located at the center rear of the evaporator housing.

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

Fig. 121: Identifying Icing Protection Temperature Sensor 

ICING PROTECTION TEMPERATURE SENSOR, FUNCTION - GF83.57-P-2106-02GH 

Function  

The icing protection temperature sensor (R35) is located in the air flow behind the evaporator. It sends its 
resistance value depending upon the temperature at the evaporator to the air conditioning control panel (S98) or 
AAC push-button control module (N22). 

At an evaporator temperature of 1 to 3°C the refrigerant compressor is switched off. This helps to prevent the 
evaporator from icing up. As a result the outlet temperature fluctuates insignificantly at the nozzles. 

IN-CAR TEMPERATURE SENSOR WITH ASPIRATOR BLOWER, LOCATION/TASK/FUNCTION - GF83.57-P-2107GH 

MODEL 163 as of 1.12.99 up to 31.8.01  

OUTSIDE TEMPERATURE SENSOR, LOCATION/TASK/FUNCTION - GF83.57-P-2110GH 

MODEL 163 as of 1.12.99 up to 31.8.01 with code (580) Air conditioning or Tempmatic for USA  

 

In-car temperature sensor 
with aspirator blower, 
location

 

GF83.57-P-
2100-01GH

 

In-car temperature sensor 
with aspirator blower, task

The in-car temperature sensor (B10/4) with aspirator blower 
(M9) records all the in-car temperatures and sends them to 
the air conditioning control module. 
The aspirator blower (M9) then uses air from the passenger 
compartment to supply a constant flow of air to the in-car 
temperature sensor (B10/4).

 

 

In-car temperature sensor 
with aspirator blower 
function

 

GF83.57-P-
2100-02GH

 

Outside temperature 
sensor position

 

GF83.57-P-
2103-02GH

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

SUN SENSOR POSITION/TASK/FUNCTION - GF83.57-P-2111GI 

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

Fig. 122: Identifying Sun Sensor 

BLENDING AIR FLAP ACTUATOR MOTOR, LOCATION/TASK/FUNCTION - GF83.57-P-2112GC 

MODEL 163 up to 31.8.01, 168 with code (580) Air conditioning or Tempmatic for USA  

 

Outside temperature 
sensor, task

The outside temperature sensor (B10/5) records all the outside 
temperature and sends it to the air conditioning control module 
(N19).

 

 

Outside temperature 
sensor function

 

GF83.57-P-
2103-01GH

 

Sun sensor, 
location

The sun sensor (B32) is located behind the instrument cluster in the instrument panel.

 

 

Sun sensor, 
task

The sun sensor (B32) measures the intensity and direction of the solar radiation.

 

 

Sun sensor, 
function

The sun sensor (B32) records the intensity and angle of incidence of the solar radiation 
onto the vehicle. This makes it possible, dependent on the solar radiation intensity 
(brightness) the in-car temperature and the blower speed to be automatically adjusted.

 

Blending air flap 

GF83.57-P-

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

BLENDING AIR FLAP ACTUATOR MOTOR, LOCATION/TASK/FUNCTION - GF83.57-P-2112GI 

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

Fig. 123: Identifying Blending Air Flap Actuator Motor 

ICING PROTECTION TEMPERATURE SENSOR, LOCATION/TASK/FUNCTION - GF83.57-P-2113GH 

  actuator motor, location Model 168

2105-01GC

   

Model 163

GF83.57-P-
2105-01GH

 

Blending air flap 
actuator motor, task

The blending air flap actuator motor (M16/8) serves to set 
the air conditioning system's ventilation temperature.

 

 

Blending air flap 
actuator motor, function

Model 168

GF83.57-P-
2105-02GC

   

Model 163

GF83.57-P-
2105-02GH

 

Blending air flap 
actuator motor, location

The blending air flap actuator motor (M2/6) is located at the 
top center of automatic air conditioner housing.

 

 

Blending air flap 
actuator motor, task

The blending air flap actuator motor (M2/6) serves to set the 
air conditioning system's ventilation temperature.

 

 

Blending air flap 
actuator motor, function

 

GF83.57-P-
2105-02GI

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me