2015 MERCEDES-BENZ GLK-CLASS SUV check engine

Display messagesPossible causes/consequences and M Solutions
¯
Eng. Start Not PosZ
sible In ..km
The DEF system is malfunctioning. A warning tone also sounds.
X Visit a qualified specialist workshop immediately.
¯
Eng. Start Not PosZ
sible
The DEF system is malfunctioning. A warning tone also sounds.
You can no longer start the engine.
X Consult a qualified specialist workshop immediately.
Driving systems
Display messagesPossible causes/consequences and M Solutions
À
Attention Assist:
Take a Break!
Based on certain criteria, ATTENTION ASSIST has detecte d fatigue
or a lack of concentration on the part of the driver. A warning tone
also sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good tim e so you get
enough rest.
À
Attention Assist
Inoperative
ATTENTION ASSIST is inoperative.
X Visit a qualified specialist workshop.
ë
Off
The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later ( Y page 184).
The HOLD function is deactivated. When the brake pedal i s firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 184).
Radar Sensors DeacZ
tivated See OperaZ
tor's Manual
The radar sensor system is deactivated.
X Switch on the radar sensor system ( Y page 233).
250Display messages
On-board computer and displays

ProblemPossible causes/consequences and M Solutions
֊
The yellow ESP®
warn-
ing lamp flashes while
the vehicle is in motion.ESP ®
or traction control has intervened because there is a r isk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X When pulling away, only depress the accelerator pedal a s far as
necessary.
X Ease off the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather c onditions.
X Do not deactivate ESP ®
.
In rare cases ( Y page 71) , it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 71).
å
The yellow ESP ®
OFF
warning lamp is lit while the engine is running.ESP ®
is deactivated.
GWARNING
If ESP ®
is switched off, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
In rare cases ( Y page 71) , it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 71).
X Adapt your driving style to suit the road and weather c onditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop.
÷ä å
The yellow ESP ®
and
ESP ®
OFF warning
lamps are lit while the
engine is running.ESP ®
, BAS, BAS PLUS, PRE

Engine
ProblemPossible causes/consequences and M Solutions
;
The yellow Check
Engine warning lamp
lights up while the
engine is running.There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
iIn some states, you must immediately visit a qualified sp ecial-
ist workshop as soon as the yellow Check Engine warning lam p
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations a pply in
the state in which you are currently driving.
8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion. In addition,
the ; Check Engine
warning lamp may light
up.The fuel system pressure is too low. The fuel filler cap i s not closed
correctly or the fuel system is leaking.
X Observe the additional display messages in the multifunction
display.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist work-
shop.
8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station.
Warning and indicator lamps in the instrument cluster267
On-board computer and displays
Z

ProblemPossible causes/consequences and M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.The coolant level is too low.
If the coolant level is correct, the airflow to the eng ine radiator may
be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
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 Check the coolant level and add coolant ( Y page 303). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. drivin g in moun-
tainous terrain, and stop-and-go traffic.
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow to the engine radiator may be blocked or the coo lant level may
be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can ca use 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 Observe the additional display messages in the multifunction
display.
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.
Warning and indicator lamps in the instrument cluster269
On-board computer and displays
Z

ProblemPossible causes/consequences and M Solutions
X
Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Check the coolant level and add coolant ( Y page 303). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. drivin g in moun-
tainous terrain, and stop-and-go traffic.
Driving systems
ProblemPossible causes/consequences and M Solutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds.GWARNING
You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
There is a risk of an accident.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC PLUS ( Y page 176) and
PRE

! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
X Make sure that the windshield wipers are
turned off.
XPull release lever : on the hood.
The hood is released.
X Reach into the gap, pull hood catch han-
dle ; up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood
X Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.
Engine oil
General notes on the oil level
Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high engine
speeds.
Depending on the engine, the oil dipstick may be in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
Example: vehicles with a gasoline engine
Engine compartment301
Maintenance and care
Z

Example: vehicles with a diesel engine
XPark the vehicle on a level surface.
To check the oil level with the engine at
operating temperature, switch the engine
off and wait for approximately five minutes.
X Pull oil dipstick : out of the dipstick guide
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
If the level is between MIN mark = and
MAX mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark =
or below, add 1.1 US qt (1.0 liter) engine oil.
Adding engine oil
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil is not spilled next to
the filler neck. Let the engine cool down and
thoroughly clean the engine oil off the com-
ponents before starting the engine.
HEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a ser-
vice system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
center.
Damage to the engine or exhaust system is caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R replacing engine oil and oil filters after
the interval for replacement specified by
the service system has been exceeded
R using engine oil additives.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic con-
verter. Have excess oil siphoned off.
Example: engine oil cap
X Turn cap : counter-clockwise and remove
it.
X Add engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l) of
engine oil.
302Engine compartment
Maintenance and care

XReplace cap : on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.
X Check the oil level again with the oil dip-
stick ( Y page 301).
Further information on engine oil
( Y page 377).
Checking and adding other service
products
Checking coolant level
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
The engine cooling system is pressurized, par-ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled down.
X Turn the SmartKey to position 2 in the igni-
tion lock ( Y page 149).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 149).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
XSlowly turn cap : half a turn counter-
clockwise and allow excess pressure to
escape.
X Turn cap : further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough coolant in coolant expansion tank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar = in the fuel
filler neck when warm, there is enough
coolant in expansion tank ;.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y page 378).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
Engine compartment303
Maintenance and care
Z