air condition MERCEDES-BENZ ML320 1997 Complete Repair Manual

Fig. 51: Identifying Air Condi tioning Components In Passenger Compartment (2 Of 2)
Location of components in passenger compartment as of 12/99
Fig. 52: Identifying Air Conditioning Components
- Location Of Components In Passenger

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 62 © 2006 Mitchell Repair Information Company, LLC.

Compartment As Of 12/99
Location of components in engine compartment
Fig. 53: Identifying Air Conditioning Components
- Location Of Components In Engine Compartment
Location of components, refrigeration technology part up to 11/99

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 63 © 2006 Mitchell Repair Information Company, LLC.

TABLE OF CONTENTS, AIR CONDITIONING (TAC) FUNCTION DESCRIPTION - GF83.30-P-0999GH
MODEL 163 up to 31.8.01 with code (580) Air conditioning or Tempmatic for USA
AIR CONDITIONING CONTROL MODULE FUNCTION - GF83.30-P-2001GH
MODEL 163 up to 31.8.01 with CODE (580) Air conditioning or Tempmatic for USA
The following components are integrated into the air conditioning control module (S98):
Blower switch (1): with 0 setting and 4 levels.
The blower switch (1) is not available as an individual part.
Temperature selector wheel (2): with the "Blue", non-heating setting and the continuously variable heater
setting.
When set to the indented position "blue" 100 % recirculated air is provided.
Air distribution switch (3): with the settings: Defroster vents, footwell, center plane and intermediate settings.
Recirculation switch ( ) : 100 % recirculation without time limit, when diode illuminates.
AC button ( ): Diode illuminates,
Refrigerant compressor ON cooling mode/air dehumidification Diode is not illuminated, refrigerant compressor
OFF no air dehumidification/coolin
g mode
Air conditioning (TAC) function GF83.30-P-0001GH
Ventilation system function GF83.10-P-2000GH
Heater circuit function GF83.20-P-2003GH
Air conditioning control unit function GF83.30-P-2001GH
Refrigerant circuit function GF83.40-P-2001GH
Temperature control, function GF83.57-P-2000GH
Heater booster, functionEngine 612.963GF83.70-P-0005GH
Starting heater operation, functionEngine 612.963GF83.70-P-2000GH
Terminate heater operation functionEngine 612.963GF83.70-P-2002GH
Regulate heater operation, functionEngine 612.963GF83.70-P-2004GH
Cancel heater operation, functionEngine 612.963GF83.70-P-2005GH
Air conditioning, location of components GF83.30-P-0003-01GH

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 65 © 2006 Mitchell Repair Information Company, LLC.

Fig. 56: Identifying Blower Switch, Temperature Selector Wheel And Air Distribution Switch
AIR CONDITIONING CONTROL MODULE, LOCATION - GF83.30-P-2102-02GH
The AC control module (N19) is located behind the center console to the left of the evaporator housing.
Fig. 57: Identifying AC Control Module

Blower switch, location/task/design/function GF83.25-P-2100GC
Air distribution switch, location/task/design/ function GF83.25-P-2101GH
Temperature selector wheel, location/task/ design/function GF83.25-P-2102GC
Air recirculation switch, location/task/design/ function GF83.10-P-2117GH
AC button, location/task/function GF83.30-P-2103GH
AC control module location/task/function GF83.30-P-2102GH
All-activity module, location/task/function GF54.21-P-4110GH

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 66 © 2006 Mitchell Repair Information Company, LLC.

AC CONTROL MODULE LOCATION/TASK/FUNCTION - GF83.30-P-2102GH
MODEL 163 up to 31.8.01 with CODE (580) Air conditioning or Tempmatic for USA
AC BUTTON, FUNCTION - GF83.30-P-2103-01GH
Function
Pressing the AC button ( ) switches on the cooling mode.
AC button ( ) pressed
Diode is illuminated, cooling mode/air dehumidification, refrigerant compressor ON
AC button ( ) not depressed
Diode not illuminated, no air dehumidification/no cooling mode, refrigerant compressor OFF
The AC button ( ) is connected to the A/C control module, which regulates the refrigerant compressor
through the all-activity module. The refrigerant compressor is only active when the engine is running and the
blower switched on. To be able to determine the cut-in point for the electromagnetic coupling on the refrigerant
compressor, the all-activity module must receive additional data from the CAN bus, such as, e.g. the engine
speed.
AC BUTTON, LOCATION - GF83.30-P-2103-02GH
The AC button ( ) is located in the air conditioning control module (S98).

Air conditioning
control module,
location
GF83.30-P-
2102-02GH

Air conditioning
control module,
task
Control of air conditioning
Recording input signals of various components
Internal processing of input signals
Sending of control signals to various components


Air conditioning
control module,
function
The AC control module records the input signals of various
components, in order to check the preconditions for proper and intended
operation. It sends control signals to the following components:
Blending air flap actuator motor, fresh air/recirculated air flap actuator
motor, All-activity module.
The air conditioning (tempmatic) control module (TAC) receives input
data from the following devices: AC button, in-car temperature sensor,
temperature selector wheel, blower switch, icing protection temperature
switch, blending air flap position signal.


2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 67 © 2006 Mitchell Repair Information Company, LLC.

Fig. 58: Identifying AC Button On Air Conditioning Control Module
AC BUTTON, LOCATION/TASK/FUNCTION - GF83.30-P-2103GH
MODEL 163 up to 31.8.01 with CODE (580) Air conditioning or Tempmatic for USA
EVAPORATOR HOUSING, POSITION - GF83.30-P-2104-01GH
The evaporator housing (1) is located below the instrument panel.
Fig. 59: Identifying Evaporator Housing

EVAPORATOR HOUSING, FUNCTION - GF83.30-P-2104-02GH
AC button,
location GF83.30-P-2103-
02GH
AC button, taskThe AC button is used to switch the air conditioning system on
and off.
AC button,
function GF83.30-P-2103-
01GH

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 68 © 2006 Mitchell Repair Information Company, LLC.

Operating condition: Air ducting in heating mode
Fig. 60: Identifying Evaporator Housing Function
- Operating Condition Air Ducting In Heating Mode
Operating condition: HEATING Function
In the heating operating status, the fresh air (A) is drawn in by the blower (5) into the evaporator housing and
routed through the dust filter (3). The air purified by the dust filter (3) is then routed through the evaporator (2)
and dried there. The fresh air (B), which has been dried, cooled and cleaned, is subsequently routed through the
heat exchanger (1). This air conduction is controlled via the setting of the blending air flaps (6).
The fresh air (B), which has been dried, cooled and cleaned, is heated up again in the heat exchanger (1). The
warm air (C) is conducted via the air outlets (E, F, M and S) into the vehicle interior. The recirculated air flap
(4) is closed.
Operating condition: Air ducting in cooling mode

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 69 © 2006 Mitchell Repair Information Company, LLC.

Fig. 61: Identifying Evaporator Housing Function - Operating Condition Air Ducting In Cooling Mode)
Operating condition: cooling Function
In the cooling operating status, the fresh air (A) is drawn in by the blower (5) into the evaporator housing and
routed through the dust filter (3). The air purified by the dust filter (3) is then routed through the evaporator (2)
and dried there. The fresh air (B), which has been dried, cooled and cleaned, is subsequently routed around the
heat exchanger (1). This air conduction is controlled via the setting of the blending air flaps (6).
The dried, cooled and cleaned air (B) is routed directly into the passenger compartment via the air outlets (E, F,
M and S). The recirculated air flap (4) is closed.
Operating condition: Blend air ducting (warm/cold) closed-loop operation

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 70 © 2006 Mitchell Repair Information Company, LLC.

Fig. 62: Identifying Evaporator Housing Function - Operating Condition Blend Air Ducting
(Warm/Cold) Closed-Loop Operation
Operating condition: Blend air (warm/cold) Function
In the blend air operating status, the fresh air (A) is drawn in by the blower (5) into the evaporator housing and
routed through the dust filter (3). The air purified by the dust filter (3) is then routed through the evaporator (2)
and dried there. Some of the dried, cold and cleaned air (B) is routed through the heat exchanger (1) and some is
routed around the heat exchanger (1). This air conduction is controlled via the central setting of the blending air
flaps (6).
The air (B), which has been dried, cooled and cleaned by the heat exchanger (1) is heated up again. After
passing through the blending air flaps (6) this heated air (C) is mixed up to form blend air (D) with the dried,
cooled and cleaned air, which was routed around the heat exchanger (1). This blend air (D) is then routed via
the air outlets (E, F, M and S) into the passenger compartment. The recirculated air flap (4) is closed.
Operating condition: Air ducting "recirculation air" in cooling mode

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 71 © 2006 Mitchell Repair Information Company, LLC.

Fig. 63: Identifying Evaporator Housing Function - Operating Condition Air Ducting Recirculation Air
In Cooling Mode)
Operating condition: Cooling down "recirculation air" Function
In the cooling mode with recirculating air the blower (5) draws the recirculated air (A) from the passenger
compartment over the opened recirculated air flaps (4) into the evaporator housing and routes it through the dust
cleaner (3). The air purified by the dust filter (3) is then routed through the evaporator (2) and dried there. The
fresh air (B), which has been dried, cooled and cleaned, is subsequently routed around the heat exchanger (1).
This air conduction is controlled via the setting of the blending air flap (6).
The dried, cooled and cleaned air (B) is routed directly into the passenger compartment via the air outlets (E, F,
M and S). The supply of fresh air is cut off by the recirculated air flap (4).
EVAPORATOR HOUSING, TASK - GF83.30-P-2104-04GH
The evaporator housing houses the following components:
Air ducting flaps
Dust filter
Blower
Series resistor group
Evaporator
Heating system heat exchanger
Expansion valve

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 72 © 2006 Mitchell Repair Information Company, LLC.