
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 some fluids which 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 traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 181).
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
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 †. #
See Owner's Manual See Owner's Manual 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
! Do not continue driving. The engine could otherwise overheat.
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 181).
X Consult a qualified specialist workshop. Display
messages
269On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Tyre press. moni‐
Tyre press. moni‐
tor currently tor currently
unavailable unavailable No signals can be received from the tyre pressure sensors due to
strong RF interference. The tyre pressure monitor is temporarily
malfunctioning.
X Drive on.
The tyre pressure monitor restarts automatically as soon as the
cause has been rectified. Wheel sensor(s) Wheel sensor(s)
missing missing There is no signal from the tyre pressure sensor of one or several
wheels. The pressure of the affected tyre is not displayed in the
multifunction display.
X Have the faulty tyre pressure sensor replaced at a qualified spe-
cialist workshop. Tyre press. moni‐ Tyre press. moni‐
tor tor
inoperative
inoperative No
No
wheel sensors
wheel sensors The wheels fitted do not have suitable tyre pressure sensors. The
tyre pressure monitor is deactivated.
X Fit wheels with suitable tyre pressure sensors.
The tyre pressure monitor is activated automatically after driv-
ing for a few minutes. Tyre press. moni‐ Tyre press. moni‐
tor inoperative tor inoperative The tyre pressure monitor is faulty.
X Visit a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
M
MSolutions Depress brake to
Depress brake to
start engine start engine You have attempted to start the engine with the transmission in
position
Nwithout depressing the brake pedal.
X Depress the brake pedal. To shift out of P To shift out of P
or N, depress or N, depress
brake and start brake and start
engine engine You have attempted to shift the selector lever to position
Ror D
without starting the engine.
X Start the engine.
X Depress the brake pedal.
i It is only possible to move the selector lever from position
Pto
the desired position if you depress the brake pedal. Only then
can the parking lock be deactivated. If you do not depress the
brake pedal, the DIRECT SELECT lever can still be moved but the parking lock remains engaged.
i At transmission fluid temperatures below
Ò20 † you can only
shift out of position Pinto another transmission position when
the engine is running. 278
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions 4matic inoperative
4matic inoperative 4MATIC is malfunctioning. The vehicle is only driven by the front
wheels.
X Visit a qualified specialist workshop. A The tailgate is open.
G WARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The bonnet is open.
A warning tone also sounds.
G WARNING
The open bonnet may then block your view when the vehicle is in
motion.
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.
X Secure the vehicle against rolling away (Y page 181).
X Close the bonnet. C At least one door is open. A warning tone also sounds.
X Close all doors. j
Check trailer Check trailer
hitch lock hitch lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose.
There is a risk of an accident. 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 181).
X Engage the trailer coupling's ball coupling in the end position
(Y page 226). Display
messages
281On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions &
inoperative Bat‐ inoperative Bat‐
tery weak tery weak The on-board voltage is too low The auxiliary heating has switched
itself off or cannot be switched on (Y page 150).
X Drive for a considerable distance.
The battery charges. The auxiliary heating is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative inoperative
Refuel
Refuel
vehicle
vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot
be switched on (Y page 150).
X Refuel at the nearest filling station. &
inoperative See inoperative See
Owner's Manual Owner's Manual The auxiliary heating is temporarily malfunctioning or faulty.
X When the vehicle is on a level surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heat- ing, waiting several minutes between each attempt
(Y page 150).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. Ð
Power Power
steering
steering mal‐
mal‐
function See Own‐
function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. Ð
Steering malfunc‐ Steering malfunc‐
tion See Owner's tion See Owner's
Manual Manual The electric steering lock is malfunctioning.
G WARNING
The steering may be locked by the electric steering lock.
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.
X Secure the vehicle against rolling away (Y page 181).
X Do not drive on and consult the nearest qualified specialist
workshop. 282
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions _
Before starting Before starting
the engine, turn the engine, turn
the the
steering
steering wheel.
wheel. The electric steering lock was unable to unlock the steering.
X Remove the key from the ignition lock.
X To unlock the steering, move the steering wheel slightly.
X Insert the key into the ignition lock again. Telephone No ser‐
Telephone No ser‐
vice vice Your vehicle is outside the network provider's transmitter/
receiver range.
X Wait until the mobile phone operational readiness symbol
appears in the multifunction display. ¥
Top Top
up
upwasher
washer fluid
fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Top up the washer fluid (Y page 322).Wiper malfunction‐ Wiper malfunction‐
ing ing The windscreen wipers are defective.
X Visit a qualified specialist workshop. Hazard warning
Hazard warning
lamps malfunction‐ lamps malfunction‐
ing ing The hazard warning lamps are faulty.
X Visit a qualified specialist workshop. Key
Display messages
Possible causes/consequences and
M
MSolutions Â
Key does not Key does not
belong to vehicle belong to vehicle You have put the wrong key in the ignition lock.
X Use the correct key. Â
Replace key Replace key The key needs to be replaced.
X Visit a qualified specialist workshop. Â
Change key batter‐ Change key batter‐
ies ies The key battery is discharged.
X Replace the battery (Y page 90). Display
messages
283On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Â
Key not detected Key not detected
(red display message) The key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Locate the key. Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine is running.
A warning tone also sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Insert the key into the ignition lock and bring into key mode. Â
Key not detected Key not detected
(white display mes-
sage) The key is currently undetected.
X Change the location of the key in the vehicle.
If the key still cannot be detected: X Operate the vehicle with the key in the ignition lock if necessary. Â
Remove starting Remove starting
button, then button, then
insert key insert key The key is continually undetected.
KEYLESS-GO is temporarily malfunctioning or is defective. A warn-
ing tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
General notes
Some systems perform a self test when the ignition is switched on. Some warning and indicator
lamps may temporarily switch on or flash during the test. This behaviour is nothing to be
concerned about.
The warning and indicator lamps will alert you to a malfunction if they switch on or flash after the engine is started or while driving. 284
Wa
rning and indi cator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Braking System) has been deactivated due to a
fault. Therefore, BAS (Brake Assist System), COLLISION PREVEN-
TION ASSIST PLUS, ESP ®
(Electronic Stability Program), ESP ®
trailer stabilisation, the HOLD function, hill start assist, the adap-
tive brake lights and PRE‑SAFE ®
, for example, are also deactiva-
ted.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other systems, such as the navigation system or the automatic trans-
mission, will be unavailable. Warning and indicator lamps in the instrument cluster
287On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, COLLISION PRE-
VENTION ASSIST PLUS, ESP
®
, ESP ®
trailer stabilisation, EBD
(electronic brake force distribution), the HOLD function, hill start
assist, the adaptive brake lights and PRE ‑SAFE®
, for example, are
also deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec- ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 288
Warning and indicator lamps in the instrument clusterOn-board computer and displays