2015 MERCEDES-BENZ GLK-Class engine overheat

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.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train. SmartKey positions
SmartKey 005A
To remove the SmartKey
(shift the transmission to position P)0047
Power supply for some consumers, such
as the windshield wipers
0048 Ignition (power supply for all consumers)
and drive position
0049 To start the engine
The steering is locked when you remove the
SmartKey from the ignition lock.
i The SmartKey can be turned in the igni-
tion lock even if it is not the correct Smart- Key for the vehicle. The ignition is not
switched on. The engine cannot be started.
KEYLESS-GO General notes
R Do not keep the KEYLESS-GO key:
- with electronic devices, e.g. a mobile
phone or another SmartKey
- with metallic objects, e.g. coins or metal
foil
- inside metallic objects, e.g. a metal case
This can impair the functionality of the KEY-
LESS-GO key.
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS- GO function and a detachable Start/Stop but-
ton.
The Start/Stop button must be inserted in the ignition lock and the SmartKey must be in the
vehicle.
Pressing the Start/Stop button several times
in succession corresponds to the different
SmartKey positions in the ignition lock. This is only the case if you are not depressing the
brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
The Start/Stop button can be removed from
the ignition lock. Then, you can insert the
SmartKey into the ignition lock.
i You do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. You should, however, Driving
149Driving and parking Z

If you or others come into contact with fuel,
observe the following:
R Wash away fuel from skin immediately
using soap and water.
R If fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance with- out delay.
R If fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing.
R Immediately change out of clothing which
has come into contact with fuel. G
WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged. G
WARNING
Vehicles with a diesel engine:
If you mix diesel fuel with gasoline, the flash
point is lower than that of pure diesel fuel.
When the engine is running, exhaust system
components could overheat without being
noticed. There is a risk of fire.
Never refuel with gasoline. Never mix gasoline with diesel fuel.
! Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the igni-
tion if you accidentally refuel with the
wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the wrong fuel could result in damage to the
fuel system and the engine. Notify a quali-
fied specialist workshop and have the fuel
tank and fuel lines drained completely.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not switch on the igni-
tion if you accidentally refuel with the wrong fuel. Otherwise, the fuel will enter
the fuel system. Even small amounts of the
wrong fuel could result in damage to the
fuel system and the engine. The repair
costs are high. Notify a qualified specialist
workshop and have the fuel tank and fuel
lines drained completely.
! Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
Do not get into the vehicle again during the
refueling process. Otherwise, electrostatic
charge could build up again.
If you overfill the fuel tank, fuel could spray
out when the fuel pump nozzle is removed.
For further information on fuel and fuel quality (Y page 373).
For further information on fuel and fuel qual-
ity, see the separate operating instructions. Refueling
General information The fuel filler flap is unlocked or locked auto-
matically when you open or close the vehicle with the SmartKey or with KEYLESS-GO.
The position of the 00B6fuel filler cap is dis-
played in the instrument cluster. The arrow
next to the filling pump indicates the side of
the vehicle. Refueling
163Driving and parking Z

change dynamically at the beginning of the
journey. On longer journeys, there are
fewer changes. For more dynamic changes, carry out a manual reset.
For further information on the ECO display,
see (Y page 224). Braking
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients !
On long and steep gradients, you must
reduce the load on the brakes by shifting
early to a lower gear. This allows you to take advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road sur-
face. This could cause damage to the drive train. This type of damage is not covered bythe Mercedes-Benz warranty.
Heavy and light loads G
WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time. !
Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
Wet roads 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 firsttime. This may also occur after the vehicle has
been washed.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
R Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
Servicing the brakes !
If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe 172
Driving tipsDriving and parking

You must select a low 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 system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects a slower-moving
vehicle in front, your vehicle is braked in order to maintain the preset distance to the vehicle
in front. G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 40% of the maximum braking force. If this
braking force is insufficient, DISTRONIC PLUS
warns you visually and audibly. There is a risk
of an accident. In such cases, apply the brakes yourself and
try to take evasive action.
! If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow-
ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style, DIS-
TRONIC PLUS can neither reduce the risk of
accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions. DIS- TRONIC PLUS is only an aid. You are respon-
sible for the distance to the vehicle in front,
for vehicle speed, for braking in good time and for staying in your lane.
Do not use DISTRONIC PLUS:
R in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired if:
R there is dirt on the sensors or anything else
covering the sensors
R there is snow or heavy rain
R there is interference by other radar sources
R there are strong radar reflections, for
example, in parking garages
If DISTRONIC PLUS no longer detects a vehi- cle in front, DISTRONIC PLUS may unexpect-
edly accelerate the vehicle to the stored
speed. Driving systems
177Driving and parking Z

The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max- imum permissible speed is. Observe the
legally prescribed maximum speed in the rel-evant country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies to your vehicle.
If you utilize any of the added maximum rear
axle load when towing a trailer, the vehicle/
trailer combination may not exceed a maxi-
mum speed of 60 mph (100 km/h) for rea-
sons concerning the operating permit. This
also applies in countries in which the permis-
sible maximum speed for vehicle/trailer com-
binations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison with when driving without a trailer.
Use the left-hand paddle shifter to shift into a
lower gear in good time on long and steep
downhill gradients.
i This also applies if you have activated
cruise control.
This will use the braking effect of the engine,
so that less braking will be required to main-
tain the speed. This relieves the load on the
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 R
Maintain a greater distance from the vehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from a standstill refer to sea level. When driving in mountainous areas,
note that the power output of the engine
and, consequently, the vehicle's gradient-
climbing capability, decreases with
increasing altitude.
If the trailer swings from side to side:
X Do not accelerate.
X Do not counter-steer.
X Brake if necessary. Installing the ball coupling
G
WARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey.
! Mercedes-Benz recommends that you
only use ball couplings that have been tes- ted and approved by Mercedes-Benz. This
helps to avoid damage to the vehicle. Cover cap
X Pull protective cap 0043in the direction of the
arrow, out of ball coupling recess 0044.
X Store protective cap 0043in a safe place.
X Observe the manufacturer's installation
instructions. 214
Towing a trailerDriving and parking

R
When you couple up a trailer, check at reg-
ular intervals that the load is firmly secured.If the trailer is equipped with trailer lights
and brakes, check the trailer to ensure that
these are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that the trailer can activate its own brakes. Thenincrease the pressure on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
A lower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
space in relation to the vehicle you are
overtaking, before you can change back to
the original lane. Decoupling a trailer
G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake is engaged.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Close all doors and the tailgate.
X Apply the trailer's parking brake.
X Remove the trailer cable and decouple the
trailer. Permissible trailer loads and drawbar
loads
Weight specifications The gross trailer weight is calculated by add-
ing the weight of the trailer to the weight of
the load and equipment on the trailer.
You will find installing dimensions and loads
under "Technical data" (Y
page 381).
Loading a trailer R
When loading the trailer, make sure that
neither the permissible gross weight of the
trailer nor the gross vehicle weight is
exceeded. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
You can find the maximum permissible val-
ues on the type plates of your vehicle and
the trailer. When calculating how much
weight the vehicle and trailer may carry, 216
Towing a trailerDriving and parking

Useful information
i This Operator's Manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's Manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
i Read the information on qualified special-
ist workshops (Y page 27). Important safety notes
G
WARNING
If you operate information systems and com-
munication equipment integrated in the vehi- cle while driving, you will be distracted from
traffic conditions. You could also lose control of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognize function
restrictions in systems relevant to safety. The operating safety of your vehicle may be
impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make
sure your vehicle is operating safely at all times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
If the operating safety of your vehicle is
impaired, park the vehicle safely as soon as
possible. Contact a qualified specialist work-
shop.
For an overview, see the instrument panel
illustration (Y
page 33). Displays and operation
Coolant temperature display
G
WARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
The coolant temperature gauge is in the
instrument cluster on the left-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 248 ‡ (120 †).
! A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The
engine will otherwise be damaged. Tachometer
The red band in the tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached. 220
Displays and operationOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions 00AC
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
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure 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 snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). 248
Display
messagesOn-board computer and displays