MERCEDES-BENZ ML430 1997 Complete Repair Manual

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.

Blending air flap actuator
Recirculated air flap actuator motor
Electric heater booster (for engine 612.963 only) and therefore forms a complete unit.
The evaporator housing distributes the air that is required to ventilate the vehicle to the relevant air ducts and
vents depending on the required interior temperature.
The air ducting depends on various operating conditions such as:
Heating mode
Cooling mode
Blend air mode (cold/warm)
Cooling air mode with recirculated air
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTOR, POSITION - GF83.30-P-2105-01GC
The fresh air/recirculated air flap actuator motor (M16/7) is located on the A/C housing between the two fresh
air/recirculated air flaps.
Fig. 64: Identifying Fresh Air/Recirculated Air Flap Actuator Motor

FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTOR, POSITION - GF83.30-P-2105-01GH
The fresh air/recirculated air flap actuator motor (M39) is located at the side of the air intake housing on the
evaporator housin
g.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 73 © 2006 Mitchell Repair Information Company, LLC.

Fig. 65: Identifying Fresh Air/Recirc ulated Air Flap Actuator Motor
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR MOTO R, FUNCTION - GF83.30-P-2105-02GH
Function
The fresh air/recirculated air flap actuator motor (M39) is controlled via the recirculation air switch ( ) and
when the temperature selector switch is set to max. cooling output in the control module (S98).
Recirculated air mode (100 % recirculated air)
In the recirculated air mode the supply of fresh air is closed by the fresh air/recirculated air flap actuator motor
(M39) and simultaneously the recirculated air supply opened without any time limit.
Fresh air mode (100 % fresh air)
In the fresh air mode the supply of fresh air is opened by th e fresh air/ recirculated air flap actuator motor (M39)
and simultaneously the recirculated air supply closed without any time limit.
Auxiliary function at air conditioning (TAC)
When, in the cooling mode, the temperat ure selector wheel is set to max. cooling (position indented blue) then
at the same time the fres h air/recirculated air flap actuator moto r (M39) is controlled and switched to
recirculation air wi thout time limit.
FRESH AIR/RECIRCUL ATED AIR FLAP ACTUATOR, FU NCTION - GF83.30-P-2105-02GI
Function
Pressing the recirculating air push- button ( ) on the AAC push-button control module (N22) actuates the
fresh air/recirculated air flap actuator motor (M2/5) via the air conditioner bus.
In recirculation mode, the recircul ation air supply is closed off by th e fresh air/recirculated air flap.
In fresh air mode, the fresh air supply is ope ned by the fresh air/ recirculated air flap.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 74 © 2006 Mitchell Repair Information Company, LLC.

Control of fresh air/recirculated air flap via the AAC push-button control module (N22)
When the recirculating air push-button is pressed ( ) on the AAC push-button control module the system is
switched by means of the fresh air/recirculated air flap actuator motor straight to 100 % recirculation air. This is
displayed by the function LED.
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 replacement of an actuator motor it is necessary for an adjustment run to be performed using the diagnosis
assistant system (DAS), i.e. the end positions flap OPEN and SHUT are defined and retained.
AIR CONDITIONING FLUID RESERVOIR, LOCATION - GF83.30-P-2106-01GH
The fluid reservoir (6) is located in the left front of the engine compartment, next to the condenser.
Fig. 66: Identifying Air Conditioning Fluid Reservoir And Associated Components

AIR CONDITIONING FLUID RESERVOIR, FUNCTION - GF83.30-P-2106-02GC
Function
NOTE: The recirculated air function can be terminated after a set time-out in
accordance with country specifications.
NOTE: All actuators are identical.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 75 © 2006 Mitchell Repair Information Company, LLC.

The liquefied refrigerant is routed under pressure into the fluid reservoir and flows through a stainless steel
meshing to the filter block. The pores in the filter block are matched precisely to the refrigerant's molecular size.
Thus the refrigerant can flow through the filter block.
All other matter, primarily water, is held back by this molecular filter and deposited. The cleaned refrigerant
flows over a rising pipe to the expansion valve.
Whenever the system is opened, the fluid reservoir should be replaced because of the water which has
collected there in the meantime.
ALL-ACTIVITY MODULE, LOCATION - GF83.30-P-2108-02GH
The all-activity module (AAM) (N10) is located in the left-hand side of the engine compartment. It is plugged
on from below to the fuse and relay module (F1).
Fig. 67: Identifying All
-Activity Module And Relay Module
FRESH AIR/RECIRCULATED AIR FLAP ACTUATOR, LOCATION/TASK/FUNCTION - GF83.30-P-2116GC
MODELS 163 up to 31.8.01, 168 up to 28.2.01 with CODE (580) Air conditioning or Tempmatic for USA
MODEL 163 as of 1.9.01 with code (580a) Automatic air conditioning
Shown on model 163 as of 1.09.01

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 76 © 2006 Mitchell Repair Information Company, LLC.