Mercedes-Benz ML320. Manual — part 221

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
31.08.01

GF82.10-P-0001GH

Model 163 as of
1.09.01

GF82.10-P-
0001GHA

Xenon headlamps, function

Model 163, up to
31.08.01

GF82.10-P-2007-
01GH

Model 163 as of
1.09.01

GF82.10-P-2007-
01GHA

Automatic driving light actuation,
function

Model 163 as of
01.09.01

GF82.10-P-3003GH

Daytime running light control, function Model 163 as of

01.09.01

GF82.10-P-3005GH

Locator lighting, function

Model 163 as of
01.09.01

GF80.20-P-2008GH

Headlamp cut-in, function

Model 163 as of
01.09.01

GF80.20-P-2003GH

Daytime running lights, function

Model 202 with
Code 236a special
lamp circuit for
daytime running
lamps

GF82.10-P-2002A

Contents - Function description of
exterior lighting,
location/task/design/function

Models 129, 140,
163, 202, 208, 210
with code 612b
xenon headlamp unit

GF82.10-P-9999B

2001 Mercedes-Benz ML320

1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis

me

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

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,
function

Models 163.113,
163.136, 163.154,
163.172, 163.174 up to
31.08.01

GF82.10-P-2007-01GH

2001 Mercedes-Benz ML320

1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis

me

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