2012 MERCEDES-BENZ GLK SUV check engine

The maximum noseweight of the trailer draw-
bar on the ball coupling is 80 kg. However,
the actual noseweight may not be higher than
the value which is given on the trailer tow
hitch or trailer identification plates. The low-
est weight applies.
! Use a drawbar noseweight as close as
possible to the maximum permissible nose-
weight. Do not use a noseweight of less
than 50kg, otherwise the trailer may come
loose.
Note that the payload and the rear axle load
are reduced by the actual payload.
i The height of the ball coupling changes
with the load of the vehicle. If necessary,
use a trailer with a height-adjustable draw-
bar.
Driving tips i
Observe the notes on ESP ®
trailer stabi-
lisation (Y page 69).
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 permitted speed is. Observe the legally
prescribed maximum speed in the relevant
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 utilise any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not
exceed a maximum speed of 100 km/h for
reasons concerning the operating permit.
This also applies in countries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer, and it will
consume more fuel. Change into a lower gear in good time on long
and steep downhill gradients. On vehicles
with automatic transmission, you have to
select shift range
1,2or 3.
i This also applies if you have activated
cruise control or SPEEDTRONIC.
This will use the braking effect of the engine,
so less braking will be required to prevent the
vehicle from gaining 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, decrease with increas-
ing altitude.
If the trailer swings from side to side:
X Do not accelerate.
X Do not countersteer.
X Brake if necessary. Fitting the ball coupling
X Make a note of the ball coupling key num-
ber.
i You can use this number to obtain a
replacement key from a Mercedes-Benz
Service Centre. Towing a trailer
217Driving and parking Z

Display messages Possible causes/consequences and
M
MSolutions J
Brake immediately Brake immediately With the Hold function activated, you have either:
R
opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet
A tone may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Use the folding wheel chock (Y page 333), from the vehicle tool
kit to secure the vehicle against rolling away.
You can restart the engine. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red
Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
The braking efficiency may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Ypage 164).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake wear Check brake wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. PRE-SAFE PRE-SAFE
inoperative inoperative
G
WARNING
Important functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
This poses an increased risk of injury.
X Visit a qualified specialist workshop. ü If the symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y
page 53). Display
messages
249On-board computer and displays Z

Display messages Possible causes/consequences and
M
MSolutions J
Brake immediately Brake immediately A malfunction has occurred while the HOLD function or DIS-
TRONIC PLUS is active.
or
Vehicles with manual transmission: with the HOLD function acti-
vated, you have either:
R
opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet.
A tone may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Use the folding wheel chock (Y page 333), from the vehicle tool
kit to secure the vehicle against rolling away.
You can restart the engine. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red
Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
The braking efficiency may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Ypage 164).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake wear Check brake wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. PRE-SAFE PRE-SAFE
inoperative See inoperative See
Owner's Manual Owner's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. 254
Display
messagesOn-board computer and displays

Engine (4-button multifunction steering wheel)
Display messages Possible causes/consequences and
M
MSolutions Top up
Top up
coolant coolant The coolant level is too low.
X
Top up the coolant, observing the warning notes before doing
so (Y page 316).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X
If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
Stop vehicle Sw. Stop vehicle Sw.
eng. Off eng. 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 some fluids which may have leaked into
the engine compartment to catch fire.
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 traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away ( Ypage 164).
X Leave the vehicle and keep a safe distance from the vehicle 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
otherwise 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 120 †. 264
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M
MSolutions # The battery is not being charged.
A warning tone also sounds.
Possible causes:
R
faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is OK:
X Visit a qualified specialist workshop. 4
Check eng. oil Check eng. oil
level level The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X
Check the oil level when next refuelling, at the latest
(Y page 315).
X If necessary, top up the engine oil (Y page 316).
X Have the engine checked at a qualified specialist workshop if
the engine oil needs topping up more often than usual. 8
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. C There is only a very small amount of fuel in the fuel tank.
The auxiliary heating cannot be operated.
X
Refuel at the nearest filling station without fail. ¸
Please Please
replace
replace air
air
cleaner
cleaner Vehicles with a diesel engine: the engine air filter is dirty and must
be replaced.
X
Visit a qualified specialist workshop. Display
messages
265On-board computer and displays Z

Display messages Possible causes/consequences and
M
MSolutions !
Clean Clean
the
thefuel
fuel fil‐
fil‐
ter
ter Vehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.
X
Visit a qualified specialist workshop. Top up AdBlue Top up AdBlue
-Workshop- -Workshop-
The AdBlue
®
level has fallen below the reserve range. A warning
tone also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified spe-
cialist workshop. Top up AdBlue Top up AdBlue
No Start ..km
No Start ..km The AdBlue
®
level is only sufficient for the indicated distance. A
warning tone also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified spe-
cialist workshop. Top up AdBlue Top up AdBlue
Engine start not Engine start not
poss. poss.
The AdBlue
®
tank is empty. A warning tone also sounds. You can
no longer start the engine.
X Consult a qualified specialist workshop immediately. AdBlue
AdBlue
check check
The AdBlue
®
system is malfunctioning. A warning tone also
sounds.
X Visit a qualified specialist workshop. AdBlue: No start AdBlue: No start
in ..km in ..km
The AdBlue
®
system is malfunctioning. A warning tone also
sounds.
X Visit a qualified specialist workshop immediately. AdBlue AdBlue
Engine start not Engine start not
poss. poss.
The AdBlue
®
system is malfunctioning. A warning tone also
sounds. You can no longer start the engine.
X Consult a qualified specialist workshop immediately. 266
Display
messagesOn-board computer and displays

Engine (12-button multifunction steering wheel)
Display messages Possible causes/consequences and
M
MSolutions +
Top Top
up upcoolant
coolant See
See
Owner's Manual
Owner's Manual The coolant level is too low.
!
Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing
so (Y page 316).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X
If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
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 some fluids which may have leaked into
the engine compartment to catch fire.
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 traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 164).
X Leave the vehicle and keep a safe distance from the vehicle 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
otherwise 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 120 †. Display messages
267On-board computer and displays Z

Display messages Possible causes/consequences and
M
MSolutions # The battery is not being charged.
A warning tone also sounds.
Possible causes:
R
faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away ( Ypage 164).
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is OK:
X Visit a qualified specialist workshop. 4
Check eng. oil Check eng. oil
lev. when next lev. when next
refuelling refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X
Check the oil level when next refuelling, at the latest
(Y page 315).
X If necessary, top up the engine oil (Y page 316).
X Have the engine checked at a qualified specialist workshop if
the engine oil needs topping up more often than usual. 8
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. C There is only a very small amount of fuel in the fuel tank.
The auxiliary heating cannot be operated.
X
Refuel at the nearest filling station without fail. ¸
Please Please
replace
replace air
air
filter
filter Vehicles with a diesel engine: the engine air filter is dirty and must
be replaced.
X
Visit a qualified specialist workshop. 268
Display
messagesOn-board computer and displays