Page 1513 of 4133

A sensor is fitted to the front axle and to the rear axle and the sensors pick up the instantaneous vehicle level at
the control arm. These sensors (A51, A52) transmit the determined vehicle level to the control module (N71).
Headlamp range adjustment motor (E1m1, E2m1)
The position of the reflectors is signaled to the headlamp range adjustment control module (N71) by a
potentiometer in the headlamp range adjustment motor. The motors (E1 m1, E2m1) receive a command from
the control module (N71) for correcting the headlamp position. If the low beam is switched on and the key is in
position 2, the motors are referenced. The reflectors are moved to the lowest position and then, depending on
the vehicle level, moved to the correct position.
HEADLAMP RANGE ADJUSTMENT (HRA), FUNCTION - GF82.10-P-0001GHA
MODELS 163.113 /128 /154 /172 /174 as of 1.9.01, 163.157 with CODE (614) Bi-xenon headlamp unit
Function
The electrical headlamp range adjustment operates dynamically. Every change in the vehicle level is determined
and signaled to the headlamp range adjustment control module (N71) by the rear axle sensor and the front axle
sensor (A51, A52). The control module (N71) compares the vehicle level and the headlamp position. If
necessary, the headlamp setting is corrected by the control module (N71) via the headlamp range adjustment
motors (E1m1, E2m2). The headlamp position is only corrected if a modified vehicle level is signaled to the
control module (N71) by the front and rear axle sensors (A51, A52) for a specific time span.
Headlamp range adjustment control module (N71)
The headlamp range adjustment control module (N71) processes the signals from the front and rear axle sensors
(A51, A52) as well as the position of the headlamp range adjustment motors (E1m1, E2m1). After evaluating
these signals, commands are sent to the headlamp range adjustment motors (E1m1, E2m1).
Front and rear axle sensors (A51, A52)
A sensor is fitted to the front axle and to the rear axle and the sensors pick up the instantaneous vehicle level at
the control arm. These sensors (A51, A52) transmit the determined vehicle level to the control module (N71).
Headlamp range adjustment motor (E1m1, E2m1)
The position of the reflectors is signaled to the headlamp range adjustment control module (N71) by a
potentiometer in the headlamp range adjustment motor. The motors (E1 m1, E2m1) receive a command from
the control module (N71) for correcting the headlamp position. If the low beam is switched on and the key is in
position 2, the motors are referenced. The reflectors are moved to the lowest position and then, depending on
the vehicle level, moved to the correct position.
Headlamp range control
(HRC), location of
components GF82.10-P-0001-01GH
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
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Page 1514 of 4133

CONTENTS - FUNCTION DESCRIPTION OF EXTERIOR LIGHTING - GF82.10-P-0999A
MODELS 129, 140, 163 up to 31.08.01, 202, 208, 210 with CODE (612b) xenon headlamp unit
MODEL 163 as of 1.9.01 with CODE (614) Bi-xenon headlamp unit
MODEL 202 with CODE (236a) Special light circuit for daytime running lamps
Headlamp range control
(HRC), location of
components GF82.10-P-0001-
01GHA
Exterior lights, functionModels 129, 140,
202, 208, 210, with
Code 612b lamp unit
for Xenon headlampGF82.10-P-0003A
Electrical headlamp range adjustment
(HRA), location of componentsMODEL 208 with
code 612b xenon
headlamp unitGF82.10-P-0001-
01A
Model 210 with code
612b xenon
headlamp lamp unitGF82.10-P-0001-
01B
Model 129 with code
612b xenon
headlamp lamp unitGF82.10-P-0001-
01C
Model 140 with code
612b xenon
headlamp lamp unitGF82.10-P-0001-
01D
Model 202 with code
612b xenon
headlamp unitGF82.10-P-0001-
01E
Model 163, up to
31.08.01GF82.10-P-0001-
01GH
Model 163 as of
1.09.01GF82.10-P-0001-
01GHA
Xenon headlamp (XENON), location of
componentsModels 129, 140,
208, 210 with code
612b xenon
headlamp lamp unitGF82.10-P-0002-
01A
Model 202 with code
612b xenon
headlamp unitGF82.10-P-0002-
01B
Headlamp range adjustment, functionModels 129, 140,
202, 208, 210 with
code 612b xenon
headlamp unitGF82.10-P-0001A
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
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Page 1515 of 4133

XENON HEADLAMPS, FUNCTION - GF82.10-P-2007-01GH
Function
The combustion chamber of the xenon lamp is filled with xenon and a mixture of metal halide salts. This
mixture is ignited by high voltage. The color of the light has a characteristic similar to daylight.
When the low beam lamps are switched on the xenon headlamp control module (E1 n1, E2n1) activates the
xenon headlamp control module and ignition module (E1n2, E2n2) via the control voltage within a few
milliseconds.
As a result of a high voltage surge (approx. 20 kV) of the ignition device, an arc forms between the electrodes,
and the xenon lamp is ignited.
When an arc of sufficient stability is detected, the control electronics of the xenon lamp control module (E1n1,
E2n1) switches over to power-limiting mode. The electric power is regulated to 35 W. A voltage converter
generates the voltage of approx. 85 V (~) necessary for the reliable function of the xenon lamp. For technical
reasons the xenon lamp has a timed startup characteristic. After switching on, 50 % of the luminosity is reached
within 1 to 2 seconds and full luminosity is reached after approx. 30 seconds.
Model 163, up to
31.08.01GF82.10-P-0001GH
Model 163 as of
1.09.01GF82.10-P-
0001GHA
Xenon headlamps, functionModel 163, up to
31.08.01GF82.10-P-2007-
01GH
Model 163 as of
1.09.01GF82.10-P-2007-
01GHA
Automatic driving light actuation,
functionModel 163 as of
01.09.01GF82.10-P-3003GH
Daytime running light control, functionModel 163 as of
01.09.01GF82.10-P-3005GH
Locator lighting, functionModel 163 as of
01.09.01GF80.20-P-2008GH
Headlamp cut-in, functionModel 163 as of
01.09.01GF80.20-P-2003GH
Daytime running lights, functionModel 202 with
Code 236a special
lamp circuit for
daytime running
lampsGF82.10-P-2002A
Contents - Function description of
exterior lighting,
location/task/design/functionModels 129, 140,
163, 202, 208, 210
with code 612b
xenon headlamp unitGF82.10-P-9999B
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
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Page 1516 of 4133

XENON HEADLAMPS, FUNCTION - GF82.10-P-2007-01GHA
The lighting technology, known as bi-xenon 70 , is located in the outer headlamps.
When the low beam lamps are switched on the xenon headlamp control module (E1 n1, E2n1) activates the
xenon headlamp control module and ignition module (E1n2, E2n2) via the control voltage within a few
milliseconds.
A high-voltage surge from the ignition device ignites the xenon lamps, and in doing so an electric arc is formed
between the electrodes. When an arc of sufficient stability is detected, the control electronics of the control
module (E1 n1, E2n1) switches over to power-limiting mode.
The light generated previously in a gas discharge lamp (D2S lamp) is not reflected in bi-xenon 70 headlamps,
but instead it is sent directly through a lens optical system with a lens diameter of 70 mm.
Using the mask (B), which is positioned between the gas discharge lamp and the lens optical system, the beam
of light is partially masked for the low beam so that oncoming traffic is not blinded.
For the high beam, the mask (B) is electro-mechanically folded to the side using the solenoid (M).
If the solenoid (M) should fail or a supply line breaks, the mask (B) remains mechanically held in the low
beam position, always between the gas discharge lamp and the lens optical system.
In order to make the extremely bright light more acceptable to other road users, the lens aperture area with its
dotted characteristic is optically enlarged.
This is possible on account of the specially formed areas which surround the lens. In addition, the light can pass
through a number of chrome-plated strips from the rear. A portion of the diffused light is intercepted by the
lower section of the surface area and reflected to the upper section of the chrome-plated longitudinal strips.
For technical reasons the xenon lamp has a timed startup characteristic. After switch on, 50 % of the luminosity
is reached within 1 to 2 seconds and full luminosity is achieved after another approx. 30 seconds.
XENON HEADLAMP, LOCATION/DESIGN/FUNCTION - GF82.10-P-2007GH
MODELS 163.113 /136 /154 /172 up to 31.08.01 with CODE (612b) xenon headlamp unit with CODE
(U47) conversion package
MODELS 163.174 up to 31.08.01, 163.113 /128 /136 /154 /172 as of 01.09.01
Design:
From model
year 2002 (as of 1.9.01) the xenon headlamps are installed as standard.
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
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Page 1517 of 4133
Fig. 10: Identifying Xenon Headlamp Components
XENON HEADLAMP, LOCATION/DESIGN/FUNCTION - GF82.10-P-2007GHA
MODELS 163.113 /128 /154 as of 1.9.01, 163.157, 163.172 /174 as of 1.9.01 with CODE (614) Bi-xenon
headlamp unit
Design:
Xenon headlamps,
functionModels 163.113,
163.136, 163.154,
163.172, 163.174 up to
31.08.01GF82.10-P-2007-01GH
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 22 © 2006 Mitchell Repair Information Company, LLC.
Page 1518 of 4133

Fig. 11: Identifying Xenon Headlamp Components Location/Design
AUTOMATIC DRIVING LIGHT ACTUATION, FUNCTION - GF82.10-P-3003GH
MODEL 163 as of 01.09.01
The Automatic Driving Light Actuation automatically switches on the driving lights (side lamps, low beams
and license plate lamps), depending on the exterior lighting conditions (rain, snow, dusk and darkness).
Function prerequisites:
Exterior lamp switch in "AUTO" position
Circuit 15 "ON"
The sun sensor (B32) signals "Darkness" or the rain sensor (B38) signals "Rain"
Basic prerequisites for automatic driving light actuation are:
diminishing daylight intensity at dusk
darkness (tunnel, underground garage, ...)
rain or snowfall and
failure of rain/sun sensor ("Darkness" is signaled continuously)
Xenon headlamps,
function GF82.10-P-2007-
01GHA
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 23 © 2006 Mitchell Repair Information Company, LLC.
Page 1519 of 4133

Fog and other lighting influences, e.g., due to oncoming traffic, do not have any effect on the automatic
driving light actuation.
Automatic driving light actuation when starting a journey and during it
Automatic driving light actuation with driving lights is only possible when the engine is running (circuit
61 ON).
When the engine is switched off and the electronic starter switch is in position "2" (circuit 15 ON) only
the side lamps and the license plate lamps are actuated.
Driving light actuation is disabled as soon as one of the basic prerequisites changes, e.g. when changing
from darkness to daylight after driving through a tunnel.
Automatic driving light actuation at the end of a journey or in darkness
After switching off the engine (circuit 61 OFF) and when the electronic starter switch is in position
"2" (circuit 15 ON), only the side lamps and the license plate lamps remain on.
The exterior lighting is switched off as of key position "1" (circuit 15R).
DAYTIME RUNNING LIGHT ACTUATION, FUNCTION - GF82.10-P-3005GH
MODEL 163 as of 01.09.01
With daytime running lamps the low beam, the side lamps and the license plate lamps are switched on if the
engine is running (there are national variants).
Function prerequisites:
Circuit 61 "ON"
In "AUTO" position of the exterior lamp switch daytime running lamps and automatic driving lights are
OR gated, i.e. depending on the prerequisites daytime running lamps or automatic driving lights are switched
on.
For the daytime running lamp conditions, there is no difference between the positions "0" and "AUTO" of
the exterior lamp switch.
Corresponding to the national legislation, the daytime running lamps can be coded in different variants via
Star Diagnosis.
Canada and USA
Table of contents,
function description for
exterior lighting GF82.10-P-0999A
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 24 © 2006 Mitchell Repair Information Company, LLC.
Page 1520 of 4133

during the day only the low beam is on
when dark, the side lamps, license plate lamps as well as the switch and controls illumination (circuit
58d) are switched on
With halogen headlights the low beam is operated during the day with a reduced voltage
The lighting switches off automatically if the gearshift lever remains in "P" or "N" position for more than
3 min
Scandinavia
with daytime running lamps the low beam, the side lamps and the license plate lamps are active
the daytime running lamps switch off if the light switch assumes the "side lamps ON" position
Other countries
with daytime running lamps the low beam, the side lamps and the license plate lamps are active
the daytime running lamps are always active
The high beams can only be switched on if the exterior lamp switch:
is at "low beam"
is at "AUTO" and "Darkness" is detected
daytime running lamps for "Other countries" has been coded
CONTENTS - FUNCTION DESCRIPTION OF EXTERIOR LIGHTING, LOCATION/ PURPOSE/DESIGN/FUNCTION -
GF82.10-P-9999B
MODELS 129, 140, 202, 208, 210, 163 up to 31.08.01 with CODE (612b) xenon headlamp unit
MODEL 163 as of 01.09.01 with CODE (614) bi-xenon headlamp unit
Automatic driving light
actuation, function GF82.10-P-3003GH
Table of contents,
function description for
exterior lighting GF82.10-P-0999A
Axle sensor for headlamp range
adjustment, location/taskMODELS 129, 140,
202, 208, 210 with
code 612b xenon
headlamp unitGF82.10-P-2100A
Headlamp range adjustment motor,
location/ taskMODELS 129, 140,
202, 208, 210 with
code 612b xenon
headlamp unitGF82.10-P-2101A
2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:04 PMPage 25 © 2006 Mitchell Repair Information Company, LLC.