1997 MERCEDES-BENZ ML320 air condition

REAR BLOWER MOTOR, FU NCTION - GF83.10-P-2168-01GI
Function
The rear blower motor (M2/1) is actuated using the bl ower button ( ) on the rear ventilation control panel
(N72/2s3).
Pressing the blower button ( ) passes a control voltage to the rear blower motor (M2/1) via the electronic
rear ventilation blower regulat or (N29/2). This facilitates blower speed control of 0-100 %.
Automatic mode function
Pressing the Auto button ( ) on the rear ventilation control panel (N72/2s3) causes the rear blower motor to
be regulated by the AAC push- button control module (N22).
REAR BLOWER MOTOR, PO SITION/TASK/DESIGN/FUNCTION - GF83.10-P-2168GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Fig. 26: Identifying Rear Blower Motor

02GD
Blower,
locationThe rear blower motor (M2/1) is located behind the rear nozzle below
the center console.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 32 © 2006 Mitchell Repair Information Company, LLC.

BLOWER MOTOR FUNCTION - GF83.10-P-2170-01GI
Function
The AAC push-button control module (N22) passes a control voltage of 0-6 V to the blower regulator (A32n1)
via the AC bus. Depending on the control voltage which is present, this then regulates the blower motor
(A32m1) operating voltage of 0-12 V. This facilitates blower speed control of 0-100 %.
The blower motor actuation (operating voltage) is influenced by the following factors:
Blower power setting manual or AUTO
Operating functions:
Air distribution
AC OFF mode
Residual engine heat mode (actuation limited to 5 V)
Mode status (heating, cooling)
Coolant temperature
Vehicle speed
Fresh air/recirculation flap setting
Flap positions
Terminal 15 (blower ON), starter running (blower OFF)
BLOWER MOTOR LOCATION/TASK/DESIGN/FUNCTION - GF83.10-P-2170GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Blower, task
The rear blower motor (M2/1) serves to improve ventilation and cooling
in the rear.
The air that is drawn in by the blower in the evaporator housing is led to
the rear blower motor (M2/1) via air ducts.
The rear blower motor (M2/1) increases the flow of air.

Blower,
function GF83.10-P-
2168-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 33 © 2006 Mitchell Repair Information Company, LLC.

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 replacing an actuator motor an adjustment run must be performed via the Diagnosis Assistant System
(DAS), i.e. the end positions flap OPEN and SHUT are defined and retained.
REAR SHUTOFF FLAP ACTUATOR MOTOR LOCATION/TASK/FUNCTION - GF83.10-P-2171GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Fig. 28: Identifying Rear Shutoff Flap Actuator Motor

CENTER OUTLET FLAP ACTUATOR MOTOR - GF83.10-P-2172-01GI
NOTE: All actuator motors are identical.

Rear shutoff flap
actuator motor
locationThe rear shutoff flap actuator motor (M2/12) is to the left of the
automatic air conditioning housing.
Rear shutoff flap
actuator motor taskThe rear shutoff flap actuator motor (M2/12) operates the rear
shutoff flap for controlling the flow of air to the rear
compartment nozzle.


Rear shutoff flap
actuator motor
function
GF83.10-P-
2171-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 35 © 2006 Mitchell Repair Information Company, LLC.

Function
Rotating the air distribution switch in the AAC push-
button control module (N22) actuates the center outlet flap
actuator motor (M2/22) via the AC bus. The center outlet flap actuator motor (M2/22) controls the center outlet
flap, which adopts the following positions according to requirements.
Switching logic
center outlet flap closed = 0%
center outlet flap open = 100%
Automatic center outlet flap control (Auto button engaged)
The center outlet flap is opened depending on the following values
blending air flap setting
Coolant temperature
Evaporator temperature
linear up to 100 % open.
Center outlet flap control via push-button control module (Clock type switch setting of air distribution
switch)
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 replacing an actuator motor an adjustment run must be performed using the Diagnosis Assistant System
(DAS), i.e. the flap OPEN and SHUT limit positions are defined and retained.
CENTER OUTLET FLAP ACTUATOR MOTOR, LOCATION/TASK/FUNCTION - GF83.10-P-2172GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
1 o'clock 2 o'clock 3 o'clock 4 o'clock 5 o'clock6 o'clock
65% 82% 100% 68% 2%
0%
7 o'clock 8 o'clock 9 o'clock 10 o'clock 11 o'clock
12 o'clock
32% 68% 100% 82% 65%
50%
NOTE: All actuator motors are identical.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 36 © 2006 Mitchell Repair Information Company, LLC.

(DAS), i.e. the end positions flap OPEN and SHUT are defined and retained.
REAR AIR DISTRIBUTION FLAP ACTUATOR MOTOR, LOCATION/TASK/FUNCTION - GF83.10-P-2173GI
MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning
Fig. 30: Locating Rear Air Distribution Flap Actuator Motor

DEFROSTER VENT FLAP ACTUATOR MOTOR, FUNCTION - GF83.10-P-2175-01GI
Function
Pressing the defroster button ( ) on the AAC push-button control module actuates the defroster vent flap
actuator motor (M2/8) via the air conditioner bus. The defroster vent flap actuator motor (M2/8) controls the
defroster nozzle flaps, which adopt the followin
g positions, according to requirements:

Rear air distribution
flap actuator motor
locationThe rear air distribution flap actuator motor (M2/21) is to the left
of the rear blower housing, behind the rear compartment nozzle.

Rear air distribution
flap actuator motor
taskThe rear air distribution flap actuator motor (M2/21) operates the
rear air distribution flap for controlling the flow of air to the rear
compartment nozzle and the rear footwell air vents.


Rear air distribution
flap actuator motor
function
GF83.10-P-
2173-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 38 © 2006 Mitchell Repair Information Company, LLC.

Defrost function
Defroster nozzle flap open 100 %.
System switched off
Defroster nozzle flap open 100 % (This limp-home capability ensures that the windshield will not fog up even
when a malfunction has occurred)
Defroster nozzle flap control via the push-button control module
(Clock type switch setting of air distribution switch)
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.
DEFROSTER VENT FLAP ACTUATOR MOTOR, LOCATION/TASK/FUNCTION - GF83.10-P-2175GI
Model 163 as of 1.9.01 with code (580a) Automatic air conditioning
1 o'clock 2 o'clock 3 o'clock 4 o'clock 5 o'clock6 o'clock
85% 68% 50% 32% 17%
0%
7 o'clock 8 o'clock 9 o'clock 10 o'clock 11 o'clock
12 o'clock
0 % 0 % 0 % 32 % 70 %
100 %
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 39 © 2006 Mitchell Repair Information Company, LLC.

Fig. 31: Identifying Defroster Vent Flap Actuator Motor
ELECTRONIC BLOWER CONTROL UNIT, REAR VENTILATION, FUNCTION - GF83.10-P-2176-01GI
Function
The blower push-button ( ) in the rear ventilation control panel (N72/2s3) is used to send a control voltage
to the rear electronic blower regulator (N29/2). Depe nding on the control voltage (0 - 6 V) present, this then
regulates the operating voltage (0 -12 V) for the rear blow er motor (M2/1). This facilitates blower speed control
of 0-100%.
Automatic operation, function
By pressing the Auto button ( ) in th e rear ventilation control panel the control of the rear electronic blower
re
gulator and thus that of the rear blower motor is governed by the AAC push-button control module.

Defroster vent flap
actuator motor,
locationThe defroster vent flap actuator moto r (M2/8) is located at the left
side of the air conditioner housing.
Defroster vent flap
actuator motor, taskThe defroster vent flap actua tor motor (M2/8) operates the
defroster vent flaps for air flow control to the windshield defroster
vent and side window defroster vents.


Defroster vent flap
actuator motor,
function
GF83.10-P-
2175-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 40 © 2006 Mitchell Repair Information Company, LLC.

REAR ELECTRONIC BLOWER REGULATOR, LOCATION/TASK/FUNCTION - GF83.10-P-2176GI
Model 163 as of 1.9.01 with code (580a) Automatic air conditioning
Fig. 32: Identifying Rear Electronic Blower Regulator

HEATER FUNCTION - GF83.20-P-0002GH
MODEL 163 up to 31.8.01
Function
The heater enables a pleasant interior climate for the vehicle passengers in the event of different weather
conditions.
A nominal temperature is preset at the heater push-button control module temperature selector wheel. This
setting is transmitted to the blending air flaps in the heater housing via a cable and an actuation mechanism.
Rear electronic blower
regulator, locationThe rear electronic blower regulator (N29/2) is located behind
the rear nozzle below the center console.
Rear electronic blower
regulator, taskThe rear electronic blower regulator (N29/2) controls the rear
blower motor (M2/1) voltage supply depending on the relevant
blower level setting.

Rear electronic blower
regulator, function GF83.10-P-
2176-01GI

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:15 PMPage 41 © 2006 Mitchell Repair Information Company, LLC.