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  
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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  
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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  
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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  
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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  
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        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  
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        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  
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        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.