Mercedes-Benz ML320. Manual - part 681

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

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

FLUID RESERVOIR, LOCATION/PURPOSE/FUNCTION - GF83.40-P-2153GI 

MODEL 163 (except 163.128) as of 1.9.01 with CODE (580a) Automatic air conditioning  

Fig. 93: Identifying Fluid Reservoir 

 

Condenser, 
location

Model 168

GF83.40-P-2120-
02GC

   

Model 163

GF83.40-P-
2120-02GH

  Condenser task

The condenser ensures that the state of the refrigerant coming from 
the compressor changes from gaseous to liquid.

 

 

Condenser 
function

 

GF83.40-P-
2120-01GC

  Receiver position

The fluid reservoir is located in the engine compartment on the 
left front next to the condenser

 

 

Fluid reservoir, 
purpose



Filtering chemical and mechanical impurities out of the 
refrigerant  



Volume reservoir for the refrigerant  

 

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

REFRIGERANT PRESSURE SENSOR, LOCATION/TASK/FUNCTION - GF83.40-P-2156GH 

MODEL 163 up to 31.08.01 with CODE (580) Air conditioning or Tempmatic for USA  

AIR DISTRIBUTION BUTTON, LOCATION/TASK/FUNCTION - GF83.40-P-2159GI 

MODEL 163 as of 01.09 01 with CODE (580a) Automatic air conditioning in the rear ventilation control 
panel  

Fig. 94: Identifying Air Distribution Button 

AUXILIARY FAN, LOCATION/PURPOSE/FUNCTION - GF83.40-P-2162GH 

MODEL 163 up to 31.8.01 with ENGINE 111.977,112.942 /970 with CODE (580) Air conditioning or 
Tempmatic for USA  



Draining the refrigerant  

  Receiver, function  

GF83.40-P-2122-
01GI

 

Refrigerant pressure 
sensor, location

 

GF83.40-P-
2126-02GH

 

Refrigerant pressure 
sensor, task

The refrigerant pressure sensor (B12) detects the refrigerant 
pressure and sends it to the All Activity Module.

 

 

Refrigerant pressure 
sensor, function

 

GF83.40-P-
2126-01GH

 

Air distribution 
button, location

The air distribution button (

 ) is located in the center in 

the rear ventilation control panel (N72/2s3).

 

 

Air distribution 
button, task

The air distribution button (

 ) controls the air 

distribution to the rear area nozzle and the rear legroom air outlets 
for ventilating the rear area.

 

 

Air distribution push-
button function

 

GF83.40-P-
2101-01GI

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

MODEL 163 as of 1.9.01 with ENGINE 112.942 /970 with CODE (580a) Automatic air conditioning

REFRIGERANT PRESSURE AND TEMPERATURE SENSOR, FUNCTION - GF83.40-P-2171-01GI 

Detecting the refrigerant pressure  

The refrigerant pressure and temperature sensor (B12/2) detects the refrigerant pressure and sends the 
determined value via the CAN-BUS to the AAC push-button control module (N22). This value is compared 
with a stored temperature/pressure curve. 

The refrigerant pressure and temperature sensor (B12/2) operates in a pressure value range of from 0 to 35 bar. 

Shutting of the refrigerant compressor  

At the following values, the refrigerant compressor is switched off. 



refrigerant pressure < 1.75 bar = refrigerant compressor OFF  



refrigerant pressure > 30 bar = refrigerant compressor OFF  

Switching on the refrigerant compressor  

The refrigerant compressor is switched on at the following value 



refrigerant pressure > 2.25 bar = refrigerant compressor ON  

Detecting the refrigerant temperature  

The refrigerant pressure and temperature sensor (B12/2) detects the temperature of the refrigerant and sends the 
determined value via the CAN-BUS to the AAC push-button control module (N22). This value is compared 
with a stored temperature/pressure curve and the refrigerant level is determined as a result. 

With a refrigerant level that is too low, the refrigerant compressor is switched off by the AAC push-button 
control module (N22) via the CAN-BUS. 

The AC OFF mode is activated and can no longer be quit. Only when the error has been eliminated and the 
diagnostic trouble code memory in the AAC push-button control module (N22) has been erased will the system 
be operational again. 

 

Auxiliary fan, 
location

 

GF83.40-P-2115-
02GH

 

Auxiliary fan, 
purpose

The left auxiliary fan (M4m1) and right auxiliary fan (M4m2) serve 
for cooling the coolant and the refrigerant.

 

 

Auxiliary fan, 
function

up to 31.08.01

GF83.40-P-2115-
01GH

   

as of 1.09.01

GF83.40-P-2115-
01GI

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

The refrigerant pressure and temperature sensor (B12/2) operates in a temperature value range of from -10°C to 
+90°C. 

Cut-in of electric suction-type fan for engine and AC with integrated control (M4/7)  

At the following values the electric suction-type fan for engine and AC with integrated control (M4/7) is 
actuated: 



refrigerant pressure < 14 bar = fan OFF  



Refrigerant pressure > 20 bar = fan ON (100 %)  



refrigerant pressure 14 to 20 bar = Continuous linear increase in fan speed (20 -100 %)  

REFRIGERANT PRESSURE AND TEMPERATURE SENSOR POSITION/TASK/FUNCTION - GF83.40-P-2171GI 

MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning  

Fig. 95: Identifying Refrigerant Pressure And Temperature Sensor 

 

Refrigerant pressure 
and temperature sensor, 
location

The refrigerant pressure sensor (B12/2) is located at the front left 
in the engine compartment at the high-pressure line (8) between 
the refrigerant compressor (A9) and the capacitor (7).

 

 

Refrigerant pressure 
and temperature sensor, 
task

The refrigerant pressure and temperature sensor (B12/1) detects 
the refrigerant pressure and the refrigerant temperature and sends 
these values to the AAC push-button control module (N22).

 

Refrigerant pressure 

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me