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Mercedes-Benz ML320. Service manual - part 677



Blending air flap actuator



Fresh air/recirculated air flap actuator



Defroster vent flap actuator motor



Rear shutoff flap actuator motor



Footwell flap actuator



Electric heater booster (for engine 612.963 only) and therefore forms a complete unit.

AIR CONDITIONER HOUSING, LOCATION / TASK / DESIGN / FUNCTION - GF83.40-P-2105GI

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

Fig. 77: Identifying Automatic Air Conditioning Box

Automatic air
conditioning box,
location

The Automatic air conditioning box (1) is below the instrument
panel.

Automatic air
conditioning box,
purpose

The automatic air conditioning box distributes the air that is
required to ventilate the vehicle to the relevant air ducts and vents
depending on the interior temperature that is required.

Automatic air
conditioning box,
design

GF83.40-P-
2105-04GI

Automatic air
conditioning box

with engine 112, 113

GF83.40-P-

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

AC OFF BUTTON, FUNCTION - GF83.40-P-2107-01GI

Function

When the AC OFF button (

) on the automatic air conditioning push-button control module is pressed an

LED comes on, the refrigerant compressor is switched off and cooling therefore switched off The air is no
longer cooled and dried.

Vehicles with diesel engine:

Additionally the electric heater booster is switched off. All other functions are retained.

In order to switch off the refrigerant compressor the push-button control module sends a switch-off request over
the CAN. At the same time, the compressor torque value is set to "0". After a specified time delay the
refrigerant compressor is switched off.

AC OFF BUTTON, LOCATION/TASK/FUNCTION - GF83.40-P-2107GI

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

Fig. 78: Identifying Temperature Thumbwheel And AC OFF Button

function

2105-02GI

Maximum heating mode for vehicles equipped with engine
612.963 only

GF83.40-P-
2105-02GJ

AC OFF
button,
location

The AC OFF button (

) is located at the center of the lower half of

the temperature selector wheel (2) on the AAC push-button control
module (N22).

AC OFF
button, task

The AC OFF button (

) serves to switch the automatic air

conditioning on and off. Function feedback is by way of a red LED.

AC OFF
button,
function

GF83.40-P-
2107-01GI

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

REST BUTTON, FUNCTION - GF83.40-P-2109-01GI

Function

Pressing the reset button (

) on the AAC push-button control module (N22) switches on the residual engine

heat utilization system. When the engine is switched off, the residual heat heats the vehicle depending on the
temperature setting on the AAC push-button control panel (N22) and the ambient temperature in the vehicle
interior. The vehicle can be heated for approx. 30 min, with the engine switched off. The function is only
available with the ignition switched off or in position 1. If there is low voltage, the residual heat function is
automatically switched off.

The flaps are in automatic mode and the quantity of air is also automatically regulated.

The residual heat function is switched off,



if the electronic key is moved to position 2 in the starter switch,



after approx. 30 minutes,



if the battery voltage drops below 11V.

AUXILIARY FAN, FUNCTION - GF83.40-P-2115-01GH

Function

Depending on the refrigerant pressure and/or the coolant temperature the left auxiliary fan (M4m1), right
auxiliary fan (M4m2) are actuated.

The all-activity module (AAM) (N10) receives the coolant temperature from the coolant temperature sensor and
the refrigerant pressure from the refrigerant pressure sensor (B12).

The all-activity module (AAM) (N10) compares this input information with stored values and actuates the left
auxiliary fan (M4m1), right auxiliary fan (M4m2).

When the following values are indicated the left auxiliary fan (M4m1), right auxiliary fan (M4m2) are switched
on or off:



refrigerant pressure >16 bar = auxiliary fan ON



refrigerant pressure < 12 bar = auxiliary fan OFF



coolant temperature > 105°C = auxiliary fan ON



coolant temperature < 94°C = auxiliary fan OFF

AUXILIARY FAN, FUNCTION - GF83.40-P-2115-01GI

Function

Depending on the refrigerant pressure and/or the coolant temperature the left auxiliary fan (M4m1) and the right
auxiliary fan (M4m2) are actuated.

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

The all-activity module (AAM) (N10) receives the coolant temperature by the coolant temperature sensor
(B11/4) and the refrigerant pressure by the refrigerant pressure and temperature sensor (B12/2). The all-activity
module (AAM) (N10) compares this input information with stored values and actuates the left auxiliary fan
(M4m1) and the right auxiliary fan (M4m2).

When the following values are indicated the left auxiliary fan (M4m1), right auxiliary fan (M4m2) are switched
on or off:



refrigerant pressure >16 bar = auxiliary fan ON



refrigerant pressure <13 bar = auxiliary fan OFF



coolant temperature > 105°C = auxiliary fan ON



coolant temperature < 97°C = auxiliary fan OFF

AUXILIARY FAN, LOCATION - GF83.40-P-2115-02GH

The auxiliary fans are located (M4) directly in front of the condenser.

Fig. 79: Identifying Left Auxiliary Fan And Right Additional Fan

ENGINE/AIR CONDITIONING ELECTRIC FAN, FUNCTION - GF83.40-P-2118-01GH

Function

Depending on the refrigerant pressure and/or the coolant temperature the fan speed is increased infinitely.

Engines 612.963 and 628.963

The CDI control module (N3/9) receives the coolant temperature from the coolant temperature sensor and via
the all-activity module (AAM) (N10) via the CAN bus the refrigerant pressure from the refrigerant pressure
sensor (B12).

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

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