2016 MERCEDES-BENZ GLS SUV engine overheat

Running-in notes
Important safety notes
In certain driving and driving safety systems, the sensors adjust automatically while a certain dis-
tance is being driven after the vehicle has been delivered or after repairs. Full system effective-
ness is not reached until the end of this teach-in process.
Brake pads/linings and discs that are either new or have been replaced only achieve optimum
braking effect after several hundred kilometres
of driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal. The first 1,500 km
If you treat the engine with sufficient care from
the very start, you will be rewarded with excel-
lent performance for the remainder of the
engine's life.
R Drive at varying vehicle speeds and engine
speeds for the first 1500 km.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, before the rev
counter needle is Ôof the way to the red area
of the rev counter.
R Do not shift down a gear manually in order to
brake.
R Try to avoid depressing the accelerator pedal
beyond the point of resistance (kickdown).
Additional notes on running in Mercedes-AMG
vehicles:
R Do not drive at speeds above 140 km/h for
the first 1500 km.
R Only allow the engine to reach a maximum
engine speed of 4500 rpm briefly.
R Ideally, for the first 1,500 km, drive in the
Comfort drive program.
After 1,500 km, you may gradually accelerate
the vehicle to full road and engine speeds.
You should also observe these notes on running- in if the engine or parts of the drive train on your
vehicle have been replaced.
Always observe the maximum permissible
speed. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardises the oper-
ating and road safety of the vehicle. There is a risk of an accident.
Stow all objects securely in the vehicle so that
they do not get into the driver's footwell.
Always fit the floormats securely and as pre-
scribed in order to ensure that there is always sufficient room for the pedals. Do not use
loose floormats and do not place several floor-mats on top of one another. G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off. Driving
147Driving and parking Z

Use the left-hand gearshift paddle to shift to a
lower gear on long and steep downhill gradients.
Take particular note of this when driving a laden vehicle.
This also applies if you have activated cruise
control, the speed limiter or Distance Pilot
DISTRONIC.
This will use the braking effect of the engine, so
less braking will be required to maintain the
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If heavy demands are made on the brakes, do
not park the vehicle immediately. Drive on for a
short while. This allows the airflow to cool the
brakes more quickly.
If the brakes have been used only moderately,
you should occasionally test their effectiveness.
To do this, brake more firmly from a higher
speed. This improves the grip of the brakes.
Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after a car wash or
after driving through deep water.
You will have to depress the brake pedal more
firmly. Maintain a greater distance to the vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion. Limited braking performance on salt-
treated roads If you drive on salt-treated roads, a layer of salt
may form on the brake discs and pads. This can increase the braking distance considerably.
R Apply the brakes occasionally in order to pre-
vent any salt build-up. Ensure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal at the end
of the journey and when starting the next
journey.
R Maintain a much greater distance to the vehi-
cle in front.
New brake pads/linings Brake pads/linings and discs that are either new
or have been replaced only achieve optimum
braking effect after several hundred kilometres
of driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal.
For safety reasons, Mercedes-Benz recom-
mends that you only have brake pads/linings
fitted to your vehicle which have been approved
for Mercedes-Benz vehicles or which corre-
spond to an equivalent quality standard. Brake
pads/linings which have not been approved for Mercedes-Benz vehicles or which are not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance brake system
(Mercedes-AMG vehicles) The high-performance brake system is designed
for high loads. This may lead to noise when
braking. This is dependent on:
R speed
R braking force
R environmental conditions, such as tempera-
ture and humidity
The wear of individual brake system compo-
nents such as the brake pads/linings or brake
discs depends on individual driving style and
operating conditions.
For this reason, it is impossible to state a mile-
age (service life) that will be valid under all cir-
cumstances. An aggressive driving style will
lead to high wear. You can obtain further infor-
mation about this from your Mercedes-Benz
Service Centre. 174
Driving tipsDriving and parking

Hill start assist will aid you when pulling away on
a hill. Further information on hill start assist
(Y page 151).
Do not shift into transmission position Nwhen
driving off-road. You could lose control of the
vehicle if you attempt to brake the vehicle using
the service brake. If the gradient is too steep for
your vehicle, back up in reverse gear.
Always observe the approach/departure angle
values (Y page 389).
Maximum gradient-climbing capability Always observe the maximum gradient climbing
ability values (Y page 389).
Hilltops When driving up an uphill gradient, slightly
reduce pressure on the accelerator immediately
before reaching the brow of the hill. Make use of the vehicle's own impetus to travel over the
brow.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R the vehicle from travelling too quickly down
the other side
Driving downhill R
Drive slowly.
R Do not drive at an angle down steep inclines.
Steer into the line of fall and drive with the
front wheels aligned straight. Otherwise, the
vehicle could slip sideways, tip and overturn.
R Before tackling steep downhill gradients, use
the left-hand steering wheel gearshift paddle
to shift to a lower gear.
R Activate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line of fall.
R Check that the brakes are working normally
after a long downhill stretch.
i Off-road ABS is activated when the off-road
program is selected.
At speeds below 30 km/h the front wheels
lock cyclically during braking. The digging-in
effect achieved in the process reduces the
stopping distance when driving off-road. The steerability of the vehicle is considerably
reduced if the wheels lock. Driving systems
Intelligent Drive
Mercedes-Benz Intelligent Drive stands for inno- vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi- nated systems Mercedes-Benz has set a mile-
stone on the path towards autonomous driving.
Mercedes-Benz Intelligent Drive embraces all
elements of active and passive safety in one well thought-out system – for the safety of the vehi-
cle occupants and that of other road users.
Further information on driving safety systems
(Y page 68). Cruise control
General notes Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid
exceeding the set speed. You must select a
lower gear in good time on long and steep down-
hill gradients, especially if the vehicle is laden or towing a trailer. By doing so, you will make use of
the braking effect of the engine. This relieves the load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
Use cruise control only if road and traffic con-
ditions are appropriate for maintaining a steady
speed for a prolonged period. You can store any road speed above 30 km/h.
Important safety notes If you fail to adapt your driving style, cruise con-
trol can neither reduce the risk of an accident
nor override the laws of physics. Cruise control
cannot take into account road, weather or traffic
conditions. Cruise control is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good time and for staying in lane. 180
Driving systemsDriving and parking

accelerate or brake unexpectedly. There is a
risk of an accident.
Take the traffic conditions into account
before calling up the stored speed. If you do
not know what the stored speed is, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
X Remove your foot from the accelerator pedal.
Cruise control is on and, when activated for
the first time, accepts the current speed or it
adjusts the vehicle's speed to the speed
stored.
Setting a speed Bear in mind that it may take a brief moment
until the vehicle has accelerated or braked to
the set speed.
X Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
X Keep the cruise control lever pressed until the
desired speed is reached.
X Release the cruise control lever.
The new speed is stored.
X To adjust the set speed in1 km/hincre-
ments: briefly press the cruise control lever
up : or down ?to the pressure point.
The last stored speed increases or decreases
in 1 km/h increments.
X To adjust the set speed in10 km/hincre-
ments: briefly press the cruise control lever
up : or down ?beyond the pressure point.
The last stored speed increases or decreases
in 10 km/h increments.
i Cruise control is not deactivated if you
depress the accelerator pedal. For example, if
you accelerate briefly to overtake, cruise con-
trol adjusts the vehicle's speed to the speed
stored after you have finished overtaking.
Deactivating cruise control There are several ways to deactivate cruise con-
trol:
X Briefly press the cruise control lever forwards
=.
or
X Brake. or
X Briefly press the cruise control lever in the
direction of arrow ;.
The variable speed limiter is selected. LIM
indicator lamp :in the cruise control lever is
on.
Cruise control is automatically deactivated if: R you apply the electric parking brake
R you are driving at less than 30 km/h
R ESP ®
engages or you deactivate ESP ®
R you activate DSR
R you activate the Offroad Plus program (vehi-
cles with the Off-Road Engineering package)
R you shift the transmission to position Nwhile
driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise con‐
Cruise con‐
trol off trol off message in the multifunction display
for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine. Speed limiter
General notes The speed limiter brakes automatically so that
you do not exceed the set speed. You must
select a lower gear in good time on long and
steep downhill gradients, especially if the vehi-
cle is laden or towing a trailer. By doing so, you
will make use of the braking effect of the engine. This relieves the load on the brake system and
prevents the brakes from overheating and wear-ing too quickly.
You can set a variable or permanent limit speed:
R variable for speed limits, e.g. in built-up areas
R permanent for long-term speed restrictions,
e.g. when driving with winter tyres fitted
(Y page 184)
i The speed indicated in the speedometer
may differ slightly from the limit speed stored.
Important safety notes If you fail to adapt your driving style, the speed
limiter can neither reduce the risk of an accident
nor override the laws of physics. The speed lim-
iter cannot take into account road, weather or
traffic conditions. The speed limiter is only an 182
Driving systemsDriving and parking

up
: to the pressure point for a higher speed
or down ?for a lower speed.
or
X Keep the cruise control lever pressed to the
pressure point until the desired speed is set.
Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
Switching the speed limiter to passive
If you depress the accelerator pedal beyond the pressure point (kickdown), the speed limiter is
switched to passive mode. The Limiter pas‐
Limiter pas‐
sive sive message appears in the multifunction dis-
play.
You can then exceed the stored speed. The
speed limiter is activated again if you:
R drive slower than the stored speed without
kickdown
R set a new speed or
R call up the last speed stored again
The Limiter passive
Limiter passive message in the multi-
function display disappears.
Switching off the variable speed limiter There are several ways to deactivate the varia-
ble speed limiter:
X Briefly press the cruise control lever forwards
B.
or X Briefly move the cruise control lever in the
direction of arrow A.
LIM indicator lamp ;in the cruise control
lever goes out. The variable speed limiter is
switched off.
Cruise control or Distance Pilot DISTRONIC is selected.
You cannot switch the variable speed limiter off
by braking.
i The last speed stored is cleared when you
switch off the engine.
Permanent limiter
You can use the on-board computer to perma-
nently limit the speed to a value between
160 km/h(e.g. for driving on winter tyres) and
the maximum design speed (Y page 252).
Shortly before the stored speed is reached, it
appears in the multifunction display.
The permanent speed limiter remains active
even if the variable speed limiter is deactivated. You cannot exceed the stored limit speed, even
if you depress the accelerator pedal beyond the
pressure point (kickdown). Distance Pilot DISTRONIC
General notes Distance Pilot DISTRONIC regulates the speed
and automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehicles
are detected with the aid of the radar sensor
system. Distance Pilot DISTRONIC brakes auto-
matically so that the set speed is not exceeded.
You must select a lower gear in good time on
long and steep downhill gradients, especially if
the vehicle is laden or towing a trailer. By doing
so, you will make use of the braking effect of the engine. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
If Distance Pilot DISTRONIC detects that there is
a risk of a collision, you will be warned visually
and acoustically. Without your intervention, Dis- tance Pilot DISTRONIC cannot prevent a colli-
sion. An intermittent warning tone will then
sound and the distance warning lamp will light
up in the instrument cluster. Brake immediately to increase the distance to the vehicle in front,
or take evasive action, provided it is safe to do
so.
For Distance Pilot DISTRONIC to assist you
when driving, the radar sensor system must be
operational.
Distance Pilot DISTRONIC operates in the range
between 0 km/h and 200 km/h.
Do not use Distance Pilot DISTRONIC while driv- ing on roads with steep gradients.
Important safety notes G
WARNING
Distance Pilot DISTRONIC does not recognise
R people or animals
R stationary objects on the road, e.g. stopped
or parked vehicles
R oncoming vehicles or crossing traffic
As a result, Distance Pilot DISTRONIC may
neither give warnings nor intervene in such
situations. There is a risk of an accident. 184
Driving systemsDriving and pa
rking

brake system and prevents the brakes from
overheating and wearing too quickly. If you need
additional braking, depress the brake pedal
repeatedly rather than continuously.
Driving tips If the trailer swings from side to side:
X Do not accelerate under any circumstances.
X Do not countersteer.
X Brake, if necessary.
R Maintain a greater distance to the vehicle in
front than when driving without a trailer.
R Avoid braking abruptly. If possible, brake gen-
tly at first to allow the trailer to run on. Then,
increase the braking force rapidly.
R The values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine, and conse-
quently the vehicle's gradient-climbing capa-
bility from a standstill, decrease with increas- ing altitude. Swivelling the ball coupling out/in
Using the switch in the driver's door G
WARNING
If the ball coupling is not engaged, the trailer
may come loose. There is a risk of an accident. Make sure that the ball coupling is securely
engaged and locked in position.
! Do not attempt to speed the up the swing-
out procedure by applying additional pressure
with your foot. The system could otherwise be
mechanically damaged.
In order to tow a trailer with your vehicle, you
must swing out the ball coupling using the
switch in the driver's door or in the tailgate.
The trailer socket is integrated into the ball cou- pling and swivels out with it.
Release the ball coupling only when the swivel
range is unobstructed. Swivelling out:
X Make sure that the vehicle is stationary.
X Shift the transmission to position P.
X Switch the ignition on.
X Pull switch :briefly.
After a short time, the ball coupling swivels
out from under the rear bumper. It can take up to seven seconds before the ball coupling
visibly swivels out.
X Remove the protective cap from the ball cou-
pling and store it in a safe place.
Until the ball coupling vertically engages in a
securely locked position:
R indicator lamp ;flashes
R the multifunction display shows the display
message Trailer coupling extend‐ Trailer coupling extend‐
ing...
ing... .
The ball coupling swivels back into the out-of-
use position when:
R you drive off before the Trailer
Trailercoupling
coupling
extending...
extending... display message has disap-
peared from the multifunction display
R the ball coupling encounters an obstacle in
the swivel range
Folding in:
X Make sure that the vehicle is stationary and
the trailer cables are disconnected.
X Place the protective cap on the ball coupling.
X Shift the transmission to position P.
X Switch the ignition on.
X Pull switch :briefly.
After a short time, the ball coupling swivels in under the rear bumper. It can take up to seven
seconds before the ball coupling visibly swiv- els in. Towing a trailer
235Driving and parking Z

Bear in mind that the outside temperature dis-
play indicates the measured air temperature
and not the road surface temperature.
The outside temperature display is in the multi-
function display (Y page 243).
A change in the outside temperature is shown in
the multifunction display after a delay. Coolant temperature display
G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
The coolant temperature gauge is in the instru-
ment cluster on the right-hand side (Y page 35).
Under normal operating conditions and with the specified coolant level, the coolant temperature
may rise to 120 †.
At high outside temperatures and when driving
in mountainous terrain, the coolant temperature may rise to the end of the scale. Operating the on-board computer
Overview :
Multifunction display
; Right control panel
= Left control panel
X To activate the on-board computer: turn
the key to position 1in the ignition lock.
You can control the multifunction display and
the settings in the on-board computer using the buttons on the multifunction steering wheel.
You can find further information on LINGUA-
TRONIC in the separate operating instructions in vehicles with a COMAND Online multimedia sys-
tem.
You can find further information on voice-con-
trolled navigation in the manufacturer's operat-
ing instructions in vehicles with an Audio 20
multimedia system. 242
Displays and operationOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is
overheated can cause any fluids that may have leaked into the engine
compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 168).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not blocked,
e.g. by frozen slush.
X Do not start the engine again until the display message goes out and
the coolant temperature is below 120 †. The engine may otherwisebe damaged.
X Pay attention to the coolant temperature gauge.
If the temperature increases again:
X Consult a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. #
See Owner's Manual See Owner's Manual The battery is no longer being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 168).
X Consult a qualified specialist workshop. 272
Display
messagesOn-board computer and displays