MERCEDES-BENZ ML350 1997 Complete Repair Manual

opened.
the injected air is dehumidified, Reheat mode
blend air flaps controlled
footwell nozzles closed
DEFROSTER BUTTON, LOCATION / TASK / FUNCTION - GF83.40-P-2139GI
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning
Fig. 87: Identifying Blower Switch And Defroster Button

BLOWER BUTTON POSITION/TASK/FUNCTION - GF83.40-P-2144GI
MODEL 163 as of 01.09 01 with CODE (580a) Automatic air conditioning in the rear ventilation control
panel
Defroster button,
locationThe defroster button ( ) is located in the center in the upper half of
the blower switch (1) on the AAC push-button control module (N22).
Defroster button,
purposeThe defroster button ( ) starts the defroster function.
Defroster button,
function GF83.40-P-
2139-02GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Fig. 88: Identifying Blower Button
RECIRCULATING AIR PUSH-BUTTON, LOCATION/TASK/FUNCTION - GF83.40-P-2145GI
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning
Fig. 89: Identifying Recirculating Air Push
-button And Blower Switch
AUTO BUTTON, LOCATION / TASK / FUNCTION - GF83.40-P-2147GI
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning
Blower button,
locationThe blower button ( ) is located in the center in the rear
ventilation control panel.
Blower button,
taskThe blower button ( ) is used to cut in the blower motor for
fresh air and recirculating air operation.
Blower button,
function GF83.40-P-2100-
01GI
Recirculating air
push-button, positionThe recirculating air push-button ( ) is located in the center
in the lower half of the blower switch (1) on the AAC push-
button control module (N22).

Recirculating air
push-button, task
The recirculating air push-button ( ) is used to operate the
fresh air/recirculated air flap to permit air to be directed out of the
vehicle interior.
Function feedback takes place by means of a red LED.

Recirculating air
push-button, function GF83.40-P-
2102-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 108 © 2006 Mitchell Repair Information Company, LLC.

Fig. 90: Identifying Auto Button And Temperature Thumbwheel
AUTO BUTTON, LOCATION / TASK / FUNCTION - GF83.40-P-2147GJ
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning in the rear ventilation control
panel
Fig. 91: Identifying Auto Button


Auto
button,
locationThe auto button ( ) is located in the center in the upper half of the temperature
selector wheel (2) on the AAC push-button control module (N22).

Auto
button,
purposeBy pressing the auto button ( ) automatic switching is activated. Function feedback
takes place by means of a red LED.

Auto
button,
functionIn addition to regulating the temperature, the blower speed and the air distribution are also
regulated automatically in automatic mode. The blower speed is continuously controlled
depending on the temperature difference between the specified and actual values.

Auto button,
locationThe auto button ( ) is located in the center in the rear ventilation control panel
(N72/2s3).
Auto button,
purposeBy pressing the auto button ( ) automatic switching is activated.
Function feedback takes place by means of a red LED.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 109 © 2006 Mitchell Repair Information Company, LLC.

RESIDUAL HEAT BUTTON, LOCATION / TASK / FUNCTION - GF83.40-P-2148GI
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning
Fig. 92: Identifying Residual Heat Button

ELECTRIC FAN ENGINE/AIR CONDITIONING SYSTEM, LOCATION/PURPOSE/FUNCTION - GF83.40-P-2151GH
MODEL 163 up to 31.8.01 with ENGINE 113.942 /981, 612.963, 628.963
CONDENSER LOCATION/TASK/FUNCTION - GF83.40-P-2152GC
Auto button,
functionPressing the Auto button
( ) enables the air quantity and the air distribution for the rear area to be controlled
automatically by the AAC push-button control module (N22).


REST
button,
locationThe REST button ( ) is located in the center in the lower half of the
temperature selector wheel (2) on the AAC push-button control module
(N22) and is combined with the AC OFF button ( ).


REST
button,
purposeThe REST button ( ) is used to switch the residual engine heat utilization
system on and off.
Function feedback takes place by means of a red LED.


REST
button,
function
GF83.40-P-
2109-01GI
Electric fan, engine/air
conditioning GF83.40-P-
2118-02GH
Electric fan, engine/air
conditioning, purposeThe electric suction fan engine and AC with integrated
control (M4/7) serves to cool down the coolant and the
refrigerant.

Engine/air conditioning
electric fan, function GF83.40-P-
2118-01GH

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 110 © 2006 Mitchell Repair Information Company, LLC.

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,
locationModel 168GF83.40-P-2120-
02GC
Model 163GF83.40-P-
2120-02GH
Condenser taskThe 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 positionThe 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
Saturday, October 02, 2010 3:23:16 PMPage 111 © 2006 Mitchell Repair Information Company, LLC.

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, taskThe 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, locationThe air distribution button ( ) is located in the center in
the rear ventilation control panel (N72/2s3).
Air distribution
button, taskThe 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
Saturday, October 02, 2010 3:23:16 PMPage 112 © 2006 Mitchell Repair Information Company, LLC.

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,
purposeThe left auxiliary fan (M4m1) and right auxiliary fan (M4m2) serve
for cooling the coolant and the refrigerant.
Auxiliary fan,
functionup to 31.08.01GF83.40-P-2115-
01GH
as of 1.09.01GF83.40-P-2115-
01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 113 © 2006 Mitchell Repair Information Company, LLC.

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,
locationThe 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,
taskThe 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
Saturday, October 02, 2010 3:23:16 PMPage 114 © 2006 Mitchell Repair Information Company, LLC.

ENGINE AND AC ELECTRIC SUCTION FAN WITH INTEGRATED CONTROL, FUNCTION - GF83.40-P-2172-01GI
Function
Depending on the refrigerant pressure and/or on the coolant temperature the speed of the engine and AC electric
suction fan with integrated control (M4/7) is increased infinitely.
The engine and AC electric suction fan with integrated control (M4/7) receives the coolant temperature from the
coolant temperature sensor (B11/4) and the refrigerant pressure from the refrigerant pressure and temperature
sensor (B12/2).
This input information is compared by the engine and AC electric suction fan with integrated control (M4/7)
with the stored values and, if necessary, the speed of the engine and AC electric suction fan is increased to 100
%
The engine and AC electric suction fan with integrated control (M4/7) operates with AC switched on and in the
reheat mode for basic ventilation with a capacity of up to 20 %.
The basic ventilation can be switched off under the following conditions:
At an outside temperature of < or = 15°C.
The pressure-dependent fan speed remains the same.
At a driving speed of > 75 km/h.
The pressure-dependent fan speed remains the same.
An overrun time of 60 s can be set in order to ensure that the engine and AC electric suction fan with integrated
control (M4/7) will continue to operate even where the refrigerant compressor is temporarily switched off by
the icing protection.
The engine and AC electric suction fan with integrated control (M4/7) has a power rating of 850 W.
ELECTRIC SUCTION-TYPE FAN FOR ENGINE AND AC WITH INTEGRATED CONTROL, LOCATION/TASK/FUNCTION
- GF83.40-P-2172GI
MODEL 163 as of 1.9.01 with ENGINE 113.965 /981, 612.963, 628.963 with CODE (580a) Automatic air
conditioning
MODEL 163 as of 1.9.01 up to 31.8.02 with ENGINE 113.942 with CODE (580a) Automatic air
conditioning
and temperature sensor,
function GF83.40-P-
2171-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 115 © 2006 Mitchell Repair Information Company, LLC.

Fig. 96: Identifying Electric Suction-Type Fan For Engine And AC With Integrated Control
BUTTON FOR REAR AREA AIR DISTRIBUTION, LOCATION/TASK/FUNCTION - GF83.40-P-2173GI
MODEL 163 as of 01.09.01 with CODE (580a) Automatic air conditioning

Electric suction-type fan for
engine and AC with integrated
control, location


Electric suction-type fan for
engine and AC with integrated
control, taskThe electric suction-type fan for engine and AC with
integrated control (M4/7) is used to cool down the
coolant and the refrigerant.


Electric suction-type fan for
engine and AC with integrated
control, function
GF83.40-P-
2172-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 116 © 2006 Mitchell Repair Information Company, LLC.