2018 MERCEDES-BENZ GLS tow

Problem
Possible causes/consequences and P Solutions
The PASSENGER AIR
BAG OFF indicator lamp
lights up and remains lit,
even though the front-
passenger seat is occu-
pied by an adult or a per-
son of a stature corre-
sponding to that of an
adult. The classification of the person on the front-passenger seat is incor-
rect. X
Make sure the conditions for a correct classification of the person
on the front-passenger seat are met ( Y
page 52).X
If the PASSENGER AIR BAG OFF indicator lamp remains lit, the front-
passenger seat may not be used. X
Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center.
The PASSENGER AIR
BAG OFF indicator lamp
does not light up and/or
does not stay on.
The front-passenger seat
is: R
unoccupied R
occupied by the
weight of a child up to
twelve months old in a
child restraint system OCS is malfunctioning. X
Make sure there is nothing between the seat cushion and the child
seat. X
Make sure that the entire base of the child restraint system rests on
the seat cushion of the front-passenger seat. The backrest of the
forward-facing child restraint system must lie as flat as possible
against the backrest of the front-passenger seat. If necessary,
adjust the position of the front-passenger seat. X
When installing the child restraint system, make sure that the seat
belt is tight. Do not pull the seat belt tight using the front-passenger
seat adjustment. This could result in the seat belt and the child
restraint system being pulled too tightly. X
Check for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to the child
restraint system. If necessary, adjust the head restraint accord-
ingly. X
Make sure that no objects are applying additional weight onto the
seat. X
If the PASSENGER AIR BAG OFF indicator lamp remains off and/or
the PASSENGER AIR BAG ON indicator lamp lights up, do not install
a child restraint system on the front-passenger seat. It is recom-
mended that you install the child restraint system on a suitable rear
seat. X
Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center.
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes
G WARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible. G WARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special-
ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of your
passenger to have deployed air bags replaced
and to have any malfunctioning air bags56
Occupant safety
Safety

Activating the special seat belt retractor: X
Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat belt
retractor is enabled. X
Push the child restraint system down so that
the seat belt is tight and does not loosen.
Removing the child restraint system and deac-
tivating the special seat belt retractor: X
Make sure you observe the child restraint
system manufacturer's installation instruc-
tions. X
Press the release button of the seat belt
buckle and guide the seat belt tongue back
towards the belt sash guide.
The special seat belt retractor is deactivated.
Child restraint system The use of seat belts and child restraint systems
is required by law in: R
all 50 states R
the U.S. territories R
the District of Columbia R
all Canadian provinces
If you install a rearward-facing child restraint
system on the center rear seat, the rear arm rest
must be folded back as far as possible.
You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or
sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under
or behind the child restraint system. Only use
child restraint systems with the original cover designed for them. Only replace damaged
covers with genuine covers.
G WARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" ( Y
page 300).
G WARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There
is an increased risk of injury, possibly even
fatal.
Replace child restraint systems which have
been damaged or subjected to a load in an
accident as soon as possible. Have the secur-
ing systems on the child restraint system
checked at a qualified specialist workshop,
before you install a child restraint system
again.
The securing systems of child restraint systems
are: R
the seat belt system R
the LATCH-type (ISOFIX) securing rings R
the Top Tether anchorages
If it is absolutely necessary to carry a child on
the front-passenger seat, be sure to observe the
information on the "Occupant Classification
System (OCS)" ( Y
page 51). There you will also
find information on deactivating the front-
passenger front air bag.Children in the vehicle 61
Safety Z

Aut oma tic locking featu reX
To deactivate: press and hold butto n C for
about fiv e seconds until a tone sounds.X
To activate: press and hold butto n D for
about fiv e seconds until a tone sounds.
If you press on e of th e two buttons and do no t
hear a tone , th e relevan t setting has already
been selected.
The vehicl e is locke d automatically when th e
ignition is switched on and th e wheels are turn-
ing .
You could therefor e be locke d out if:R
th e vehicl e is bein g pushed.R
th e vehicl e is bein g towed.R
th e vehicl e is on a roller dynamometer.
You can also switch th e automatic locking func-
tion on and off usin g th e on-board computer
( Y
page 244).
Power closing Powe r closin g pulls th e door s and tailgat e int o
their locks automatically eve n if they are no t
completely closed. X
To power close a door : push th e door int o
th e loc k up to th e first deten t position .
Powe r closin g will pull th e door fully closed.X
To power close th e tailgate: lightl y press
th e tailgat e downwards.
Powe r closin g will pull th e tailgat e fully
closed. Unlocking/locking the driver's door
using the mechanical key
i If you want to centrally loc k th e vehicl e usin g
th e mechanical key, begi n by pressing th e
locking butto n for th e interior locking mech-
anism while th e driver's door is open . The n
proceed to loc k th e driver's door usin g th e
mechanical key.
X
Inser t th e mechanical ke y int o th e loc k of th e
driver's door as far as it will go. X
To unlock: tur n th e mechanical ke y counter-
clockwise to position G .X
To lock: tur n th e mechanical ke y clockwise as
far as it will go to position G .
If you use th e mechanical ke y to unloc k and
open th e driver's door , th e anti-thef t alarm sys-
te m will be triggered . Switc h off th e alarm
( Y
page 75).
If you loc k th e vehicl e as described above, th e
fuel filler flap is no t locked. The anti-thef t alarm
system is no t armed.
Cargo compa rt ment
Import ant safety notes
G WARNIN G
Combustion engines emi t poisonous exhaust
gase s suc h as carbon monoxide. If th e tailgat e
is open when th e engin e is running, particu-
larly if th e vehicl e is moving , exhaust fumes
could ente r th e passenger compartment.
There is a ris k of poisoning .
Turn off th e engin e before opening th e tail-
gate. Never drive wit h th e tailgat e open .84
Cargo compartment
Opening and closing

Shifting to neutral N
G WARNING
If children are left unsupervised in the vehicle,
they could: R
open the doors, thus endangering other
people or road users. R
get out and disrupt traffic. R
operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they: R
release the parking brake. R
shifting the automatic transmission out of
park position PR
Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. X
If the transmission is in position [ or ^ :
push the DIRECT SELECT lever up or down to
the first point of resistance. X
If the transmission is in position ] : depress
the brake pedal and push the DIRECT SELECT
lever up or down to the first point of resist-
ance.
If you switch the engine off with the transmis-
sion in position ^ or [ , the automatic trans-
mission shifts to \\ automatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove
the SmartKey from the ignition lock, the auto-
matic transmission shifts to ] automatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts automatically
to ] .
If you want the automatic transmission to
remain in neutral \\ , e.g. when having the vehi-
cle cleaned in an automatic, tow-through car
wash: With the SmartKey: X
Switch on the ignition. X
Depress the brake pedal and keep it
depressed. X
Shift to neutral \\ .X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
With the Start/Stop button: X
Remove the Start/Stop button from the igni-
tion lock. X
Insert the SmartKey into the ignition lock. X
Switch on the ignition. X
Depress the brake pedal and keep it
depressed. X
Shift to neutral \\ .X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
Engaging drive position D X
If the transmission is in position ^ or \\ :
push the DIRECT SELECT lever down past the
first point of resistance. X
If the transmission is in position ] : depress
the brake pedal and push the DIRECT SELECT
lever down past the first point of resistance.
Transmission position and drive pro-
gram display The current transmission position and drive pro-
gram appear in the multifunction display.
C
Transmission position
D
Gear

The arrows in the transmission position display
show how and into which transmission positions
you can shift using the DIRECT SELECT lever.
If the transmission position display on the mul-
tifunction display is not working, you should pull
away carefully to check whether the desired
transmission position is engaged. Ideally, you
should select transmission position [ and, in
Mercedes-AMG vehicles, drive program C or S .
Transmission positions E Park position
Only shift the transmission into posi-
tion P when the vehicle is stationary
( Y
page 161). The parking lock
should not be used as a brake when
parking. Always apply the electronic
parking brake in addition to the park-
ing lock in order to secure the vehi-
cle.
If the vehicle electronics are malfunc-
tioning, the transmission may be
locked in position P . Have the vehicle
electronics checked immediately at a
qualified specialist workshop.
Park position P is automatically
engaged if: R
you switch off the engine using the
SmartKey and remove the Smart-
Key R
you switch off the engine using the
SmartKey or using the Start/Stop
button and open the driver's door
or front-passenger door R
the driver's door is opened when
the vehicle is stationary or driving
at very low speed and the trans-
mission is in position D or R
F Reverse gear
Only shift the transmission into posi-
tion R when the vehicle is stationary. D Neutral
Do not shift the transmission to N
while driving. Otherwise, the auto-
matic transmission could be dam-
aged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brakes will allow you to
move the vehicle freely, e.g. to push
it or tow it.
If ESP ®
is deactivated or faulty: shift
the transmission to position N if the
vehicle is in danger of skidding, e.g.
on icy roads.
If you switch the engine off with the
transmission in position R or D , the
automatic transmission shifts to N
automatically.
! Coasting in neutral \\ may
cause damage to the drive train.
: Drive
The automatic transmission changes
gear automatically. All forward gears
are available.
Driving tips
Changing gear The automatic transmission shifts through the
individual gears automatically when it is in trans-
mission position [ . This automatic gear shift-
ing behavior is determined by: R
the selected drive program R
the position of the accelerator pedal R
the road speed
Accelerator pedal position Your style of driving influences how the auto-
matic transmission shifts gear: R
little throttle: early upshifts R
more throttle: late upshifts150
Automatic transmission
Driving and parking

Kickdown Use kickdown for maximum acceleration .X
Depress th e accelerato r pedal beyon d th e
pressur e point.
The automatic transmission shift s to a lower
gear depending on th e engin e speed.X
Eas e off th e accelerato r pedal once th e
desire d speed is reached.
The automatic transmission shift s bac k up.
Rocking the vehicle free Shifting bac k and forth between transmission
position s [ and ^ can help to free up th e
vehicl e if it get s stuck in mud or snow. The vehi-
cle's engin e managemen t system limits th e
speed to a maximum of 5 mph (9 km/h) when
shifting bac k and forth . To shift repeatedly
between transmission position s [ and ^ ,
mov e th e DIRECT SELECT lever up and down
past th e poin t of resistance.
Towing a trailer X
Drive in th e middle of th e engin e spee d range
on uphil l gradients .X
Dependin g on th e uphil l or downhill gradient,
use th e left-han d steering whee l paddl e
shifter ( Y
page 152) to select a lower gear ,
eve n if cruise control or Distanc e Pilo t
DISTRONI C are activated.
Drive programs
Slippery drive program The Slipper y drive progra m has th e followin g
characteristics :R
reduce d engin e and transmission setting s for
optimum propulsion on slipper y or snow-cov-
ere d roads.R
optimized ES P ®
stabilit y control on slipper y or
snow-covered roads. R
th e vehicl e has improved drivin g stabilit y on
slipper y or snow-covered roads, for example. Comfort drive program The Comfor t drive progra m has th e followin g
characteristics : R
comfort-oriented engin e and transmission
settings. R
optimal fuel consumption resulting from th e
automatic transmission shifting up sooner. R
th e vehicl e pullin g away mor e gentl y in
forward and revers e gears, unless th e accel-
erator pedal is depressed fully. R
th e automatic transmission shifting up
sooner. This result s in th e vehicl e bein g driven
at lower engin e speeds and th e wheels bein g
less likely to spin .
Sp ort drive program The Sport drive progra m has th e followin g char-
acteristics : R
sport y engin e and transmission settings. R
th e automatic transmission shifting up later.
th e fuel consumption possibl y bein g higher as
a result of th e later automatic transmission
shift points . R
th e suspension exhibits sport y damping (vehi-
cle s wit h AIRMATIC) .
Drive program Sp ort Plus (Mercedes-
AMG vehicles) The Sport Plu s drive progra m has th e followin g
characteristics : R
th e vehicl e exhibits particularly sport y drivin g
characteristics . R
th e vehicl e pullin g away in first gear .R
th e automatic transmission shifting up later.
th e fuel consumption possibl y bein g higher as
a result of th e later automatic transmission
shift points . R
th e suspension exhibits particularly fir m
springing and damping setting s (vehicles wit h
AIRMATIC) . R
th e ECO start/sto p function is deactivated, it
can , however , be activated again usin g th e
ECO butto n ( Y
page 145).Automatic transmission 15 1
Driving an d parking Z

Problems with the transmission Problem
Possible causes/consequences and P Solutions
The transmission has
problems shifting gear. The transmission is losing oil. X
Have the transmission checked at a qualified specialist workshop
immediately.
7G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear. The transmission is in emergency mode.
It is only possible to shift into second gear and reverse gear.X
Stop the vehicle. X
Shift the transmission to position P .X
Switch off the engine. X
Wait at least ten seconds before restarting the engine. X
Shift the transmission to position D or R .
If D is selected, the transmission shifts into second gear; if R is
selected, the transmission shifts into reverse gear. X
Have the transmission checked at a qualified specialist workshop
immediately.
9G-TRONIC:
The acceleration ability
is deteriorating.
The transmission no lon-
ger changes gear. The transmission is in emergency mode.
It is only partly possible to engage the gears or the transmission is in
position N . X
Stop the vehicle. X
Shift the transmission to position P .X
Switch off the engine. X
Wait at least ten seconds before restarting the engine. X
Shift the transmission to position D or R .X
Have the transmission checked at a qualified specialist workshop
immediately.
Transfer case This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always trans-
mitted to both axles.
! Performance tests may only be carried out
on a 2-axle dynamometer. The brake system
or transfer case could otherwise be damaged.
Contact a qualified specialist workshop for a
performance test.
! Because ESP ®
is an automatic system, the
engine and ignition must be switched off
(SmartKey in position 0 or 1 or Start/Stop
button in position 0 or 1 ) when the electric
parking brake is being tested on a brake dyna-
mometer (maximum 10 seconds).
Braking triggered automatically by ESP ®
may
seriously damage the brake system. ! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Refueling
Important safety notes
G WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion.
You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before
refueling. Refueling 155
Driving and parking Z

overfilling. DEF may leak if overfilled. Mercedes-
Benz offers a special disposable hose with over-
fill protection. You can obtain this from any
authorized Mercedes-Benz Center. DEF is avail-
able in a variety of containers and receptacles.
Only use the disposable hose with the
Mercedes-Benz DEF refill canisters.
DEF refill bottle
! Only screw on the DEF refill bottle hand-
tight. Otherwise, the thread of the DEF refill
bottle could be damaged and DEF could leak
out.
X
Unscrew the protective cap from DEF refill
bottle C .X
Place DEF refill bottle C on the filler neck as
shown and screw it on clockwise until hand-
tight. X
Press DEF refill bottle C towards the filler
neck.
The DEF tank is filled. This may take up to one
minute.
i When DEF refill bottle C is no longer
pressed, filling stops and the bottle may be
taken off again after being only partially emp-
tied. X
Release DEF refill bottle C .X
Turn DEF refill bottle C counter-clockwise
and remove it. X
Screw the protective cap onto DEF refill bot-
tle C again.
DEF refill bottles are available at many gas sta-
tions or at a qualified specialist workshop. Refill
bottles without a threaded cap do not provide
overfill protection. DEF may leak if overfilled.
Mercedes Benz offers special refill bottles with a
threaded seal. These are available at any author-
ized Mercedes-Benz Center. Parking
Important safety notes
G WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable mate-
rials come into contact with parts of the vehi-
cle which are hot. Take particular care not to
park on dry grassland or harvested grain
fields.
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P . R
start the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
! Always secure the vehicle correctly against
rolling away. Otherwise, the vehicle or its driv-
etrain could be damaged.
To ensure that the vehicle is secured against
rolling away unintentionally: R
the electric parking brake must be applied R
the transmission must be in position ] and
the SmartKey must be removed from the igni-
tion lock R
the front wheels must be turned towards the
curb on steep uphill or downhill gradients R
the empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients R
a laden vehicle must also be secured at the
rear axle with a wheel chock or similar, for
example, on uphill or downhill gradients Parking 161
Driving and parking Z