light MERCEDES-BENZ GLS 2017 Service Manual

Problems with the seat heating or seat ventilation Problem
Possible causes/consequences and P Solutions
The seat heating or seat
ventilation has switched
off prematurely or can-
not be switched on. The on-board voltage is too low because too many electrical consum-
ers are switched on. X
Switch off electrical consumers that you do not need, such as the
rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat heating or seat
ventilation will switch back on automatically.
Steering wheel
Important safety notes
G WARNING
You could lose control of your vehicle if you do
the following while driving: R
adjust the driver's seat, head restraint,
steering wheel or mirrors R
fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt
before starting the engine.
G WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The electrically adjustable steering wheel can
still be adjusted when there is no SmartKey in
the ignition lock.
Adjusting the steering wheel man-
ually
G WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose control of the vehicle. There is a risk of an
accident.
Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion.
C
Release lever D
Adjusts the steering wheel height

G WARNING
The exterior mirror on the front-passenger
side reduces the size of the image. Visible
objects are actually closer than they appear.
This means that you could misjudge the dis-
tance from road users traveling behind, e.g.
when changing lane. There is a risk of an acci-
dent.
For this reason, always make sure of the
actual distance from the road users traveling
behind by glancing over your shoulder.
X
Turn the SmartKey to position 1 or 2 in the
ignition lock ( Y
page 138).X
Exterior mirror on the driver's side: press but-
ton C .
Exterior mirror on the front-passenger side:
press button D .
The indicator lamp in the corresponding but-
ton lights up in red.
The indicator lamp goes out again after some
time. You can adjust the selected exterior
mirror using button

Exterior mirror pushed out of position If an exterior mirror has been pushed out of
position, proceed as follows: X
Vehicles without electrically folding exte-
rior mirrors: move the exterior mirror into
the correct position manually. X
Vehicles with electrically folding exterior
mirrors: press and hold mirror-folding but-
ton C until you hear a click and the mirror
engages in position audibly.
The mirror housing is engaged again and you
can adjust the exterior mirrors as usual
( Y
page 107).
Automatic anti-glare mirrors
G WARNING
Electrolyte may escape if the glass in an auto-
matic anti-glare mirror breaks. The electrolyte
is harmful and causes irritation. It must not
come into contact with your skin, eyes, res-
piratory organs or clothing or be swallowed.
There is a risk of injury.
If you come into contact with the electrolyte,
observe the following: R
Rinse off the electrolyte from your skin
immediately with water. R
Immediately rinse the electrolyte out of
your eyes thoroughly with clean water. R
If the electrolyte is swallowed, immediately
rinse your mouth out thoroughly. Do not
induce vomiting. R
If electrolyte comes into contact with your
skin or hair or is swallowed, seek medical
attention immediately. R
Immediately change out of clothing which
has come into contact with electrolyte. R
If an allergic reaction occurs, seek medical
attention immediately. The rear-view mirror and the exterior mirror on
the driver's side automatically go into anti-glare
mode if the following conditions are met simul-
taneously: R
the ignition is switched on and R
incident light from headlamps strikes the sen-
sor in the rear-view mirror
The mirrors do not go into anti-glare mode if
reverse gear is engaged or if the interior lighting
is switched on.
Parking position for the exterior mir-
ror on the front-passenger side
Setting and storing the parking position You can position the front-passenger side exte-
rior mirror in such a way that you can see the
rear wheel on that side as soon as you engage
reverse gear. You can store this position.
Using reverse gear
C
Button for the driver's side exterior mirror D
Button for the front-passenger side exterior
mirror

Exterior lighting
General notes For reasons of safety, Mercedes-Benz recom-
mends that you drive with the lights switched on
even during the daytime. In some countries,
operation of the headlamps varies due to legal
requirements and self-imposed obligations.
Setting the exterior lighting
Setting options Exterior lighting can be set using: R
the light switch R
the combination switch ( Y
page 113)R
the on-board computer ( Y
page 239)
Light switch
Operation
G c
Left-hand standing lampsH d
Right-hand standing lampsI `
Parking lamps, license plate and
instrument cluster lightingJ q
Automatic headlamp mode, controlled
by the light sensor
K X
Low-beam/high-beam headlamps

The daytime running lamps improve the visibility
of your vehicle during the day. To do this, the
daytime running lamps function must be
switched on using the on-board computer
( Y
page 239).
If the engine is running and you turn the light
switch to ` or X , the manual settings
take precedence over the daytime running
lamps.
Low-beam headlamps Even if the light sensor does not detect that it is
dark, the parking lamps and low-beam head-
lamps switch on when the ignition is switched on
and the light switch is set to the X position.
This is a particularly useful function in the event
of rain and fog. X
To switch on the low-beam headlamps:
turn the SmartKey in the ignition lock to posi-
tion 2 or start the engine.X
Turn the light switch to X .
The green X indicator lamp in the instru-
ment cluster lights up.
Rear fog lamp The rear fog lamp improves visibility of your
vehicle for the traffic behind in the event of thick
fog. Please take note of the country-specific
regulations for the use of rear fog lamps. X
To switch on the rear fog lamp: turn the
SmartKey in the ignition lock to position 2 or
start the engine. X
Turn the light switch to X or q .X
Press the ^ button.
The yellow ^ indicator lamp in the instru-
ment cluster lights up. X
To switch off the rear fog lamp: press the
^ button.
The yellow ^ indicator lamp in the instru-
ment cluster goes out.
Parking lamps
! If the battery charge is very low, the parking
lamps or standing lamps are automatically
switched off to enable the next engine start.
Always park your vehicle safely and in a well lit
area, in accordance with the relevant legal
stipulations. Avoid using the ` parking
lamps over a period of several hours. If pos-
sible, switch on the right-hand d or left-
hand c standing lamps. X
To switch on: turn the light switch to ` .
The green ` indicator lamp in the instru-
ment cluster lights up.
Standing lamps Switching on the standing lamps ensures the
corresponding side of t he vehicle is illuminated.X
To switch on the standing lamps: the
SmartKey should not be in the ignition lock or
it should be in position 0 .X
Turn the light switch to c (left-hand side of
the vehicle) or d (right-hand side of the
vehicle).
Vehicles towing a trailer: both the right-hand
and left-hand standing lamps (tail lamps) are
always illuminated on the trailer.
Combination switch
C
High-beam headlamps D
Turn signal, right

The blue W indicator lamp in the instru-
ment cluster lights up when the high-beam
headlamps are switched on. X
To switch off the high-beam head-
lamps: move the combination switch back to
its normal position.
The blue W indicator lamp in the instru-
ment cluster goes out.
Vehicles with Adaptive Highbeam Assist: if
Adaptive Highbeam Assist is activated, it auto-
matically controls activation and deactivation of
the high-beam headlamps ( Y
page 115).
Hazard warning lamps
X
To switch on the hazard warning
lamps: press button C .
All turn signals flash. If you now switch on a
turn signal using the combination switch, only
the turn signal lamp on the corresponding
side of the vehicle will flash. X
To switch off the hazard warning lamps:
press button C .
The hazard warning lamps automatically switch
on if: R
an air bag is deployed or R
the vehicle decelerates rapidly from a speed
of above 45 mph (70 km/h) and comes to a
standstill
The hazard warning lamps switch off automati-
cally if the vehicle reaches a speed of above
6 mph (10 km/h) again after a full brake appli-
cation.
i The hazard warning lamps still operate if the
ignition is switched off. Intelligent Light System
General notes The Intelligent Light System is a system that
adjusts the headlamps automatically to suit the
prevailing driving and weather conditions. It
offers advanced functions for improved illumi-
nation of the road surface, e.g. depending on the
vehicle speed or weather conditions. The sys-
tem includes the active light function, cornering
light function, highway mode and extended
range fog lamps. The system is only active when
it is dark.
You can activate or deactivate the "Intelligent
Light System" using the on-board computer
( Y
page 239).
Active light function The active light function is a system that moves
the headlamps according to the steering move-
ments of the front wheels. In this way, relevant
areas remain illuminated while driving. This
allows you to identify pedestrians, cyclists and
animals.
Active: when the lights are switched on.
Cornering light function The cornering light function improves the illu-
mination of the road over a wide angle in the
direction you are turning, enabling better visi-
bility in tight bends, for example. It can only be
activated when the low-beam headlamps are
switched on.
Active: R
if you are driving at speeds below 25 mph
(40 km/ h) and switch on the turn signal or
turn the steering wheel R
if you are driving at speeds between 25 mph
(40 km/h) and 45 mph (70 km/h) and turn
the steering wheel
The cornering lamp may remain lit for a short
time, but is automatically switched off after no
more than three minutes.
Highway mode
Highway mode increases the range of the beam.
Active: if you are driving at a speed above
110 km/h and do not make any large steering
movements for at least 1,000 m or if you are
driving at a speed above 130 km/h.114
Exterior lighting
Lights and windshield wipers

Not active: if you are driving at speeds below
80 km/h following activation.
Extended range fog lamps The extended range fog lamps reduce the glare
experienced by the driver and improve the illu-
mination of the edge of the road.
Active: if you are driving at speeds below
40 mph (70 km/h) and you switch on the rear
fog lamp.
Not active: if, following activation, you are driv-
ing at speeds above 60 mph (100 km/h) or if you
switch off the rear fog lamp
Off-road lights The off-road lights facilitate the early recogni-
tion of objects/obstacles when driving off-road
thanks to a symmetrical, wider and brighter dis-
tribution of light from the low-beam headlamps.
Active: when driving at speeds no faster than
30 mph (50 km/h) and the off-road program
selector wheel is in position 1 or 2.
Not active: when driving at speeds above
30 mph (50 km/h).
When the off-road lights are switched on, the
cornering light function is permanently activa-
ted, the active light function is deactivated and
the headlamp range control is set to static
mode.
Cornering light function The cornering light function improves the illu-
mination of the road over a wide angle in the
direction you are turning, enabling better visi-
bility in tight bends, for example. It can only be
activated when the low-beam headlamps are
switched on.
Active: R
if you are driving at speeds below 25 mph
(40 km/h) and switch on the turn signal or
turn the steering wheel R
if you are driving at speeds between 25 mph
(40 km/h) and 45 mph (70 km/h) and turn
the steering wheel
The cornering lamp may remain lit for a short
time, but is automatically switched off after no
more than three minutes. Adaptive Highbeam Assist
General notes You can use this function to set the headlamps
to change between low beam and high beam
automatically. The system recognizes vehicles
with their lights on, either approaching from the
opposite direction or traveling in front of your
vehicle, and consequently switches the head-
lamps from high beam to low beam.
The system automatically adapts the low-beam
headlamp range depending on the distance to
the other vehicle. Once the system no longer
detects any other vehicles, it reactivates the
high-beam headlamps.
The system's optical sensor is located behind
the windshield near the overhead control panel.
Important safety notes
G WARNING
Adaptive Highbeam Assist does not recognize
road users: R
who have no lights, e.g. pedestrians R
who have poor lighting, e.g. cyclists R
whose lighting is blocked, e.g. by a barrier
On very rare occasions, Adaptive Highbeam
Assist may fail to recognize other road users
that have lights, or may recognize them too
late. In this, or in similar situations, the auto-
matic high-beam headlamps will not be deac-
tivated or will be activated regardless. There is
a risk of an accident.
Always carefully observe the traffic conditions
and switch off the high-beam headlamps in
good time.
Adaptive Highbeam Assist cannot take into
account road, weather or traffic conditions.
Adaptive Highbeam Assist is only an aid. You are
responsible for adjusting the vehicle's lighting
to the prevailing light, visibility and traffic con-
ditions.
In particular, the detection of obstacles can be
impaired if: R
poor visibility, e.g. due to fog, heavy rain or
snow R
dirt on the sensors or the sensors are
obscuredExterior lighting 115
Lights and windshield wiper s Z

Switching Adaptive Highbeam Assist
on/off X
To switch on: turn the light switch to X .X
Press the combination switch beyond the
pressure point in the direction of arrow C .
The

Rear overhead control panel (thir d row of seats)
C
Readin g lamp
Interior lighting control
General notes In order to prevent the veh icle 's battery fr om
disc harg ing , the int erior lighting funct ion s are
automatical ly deactivated after some time
except when the Sm artKey is in posi tion 2 in the
igniti on loc k.
The co lor and brightne ss for the ambient lighting
may be set via the multimedia system (see the
separate oper ati ng ins truct ion s).
Automatic interior lighting control X
To switch on: set the swit ch to center posi -
tion

bulbs of the same type and the specified volt-
age.
Marks on the glass tube reduce the service life
of the bulbs. Do not touch the glass tube with
your bare hands. If necessary, clean the glass
tube when cold with alcohol or spirit and rub it
off with a lint-free cloth.
Protect bulbs from moisture during operation.
Do not allow bulbs to come into contact with
liquids.
Replace only the bulbs listed ( Y
page 118).
Have the bulbs that you cannot replace yourself
replaced at a qualified specialist workshop.
If you require assistance replacing bulbs, con-
sult a qualified specialist workshop.
If the new bulb still does not light up, consult a
qualified specialist workshop.
Headlamps and lights are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times. Have
the headlamp setting checked regularly.
Overview of bulb replacement - bulb
types You can replace the following bulbs. The bulb
type can be found in the legend.
Halogen headlamps
C
Low-beam headlamp: H7 55 W
D
High-beam headlamp: H7 55 W