A requirement for the display of the contents
is that the following functions are available in the vehicle and are switched on:
R Cruise control and SPEEDTRONIC
R DISTRONIC PLUS
R Traffic Sign Assist
R Navigation
The head-up display allows the driver to see
all of the information without having to take
their eyes off the road.
Important safety notes The head-up display is only an aid and is not a
substitute for attentive driving.
Speed limits and overtaking restrictions are
not always correctly displayed. Traffic signs
always have priority over the Traffic Sign
Assist display.
The visibility of the head-up display is influ-
enced by the following conditions:
R the driver's seat position
R the positioning of the display image
R the general light conditions
R sunglasses with polarisation filters
R Wet road surfaces
R blocking of sunlight by objects on the dis-
play cover
In the event of extreme sunlight, sections of
the display may fade. This can be reversed by
switching the head-up display off and on
again.
i Vehicles with the head-up display are
equipped with a special windscreen.
Should repairs be necessary, have the
windscreen replaced at a qualified special-
ist workshop. Displays and operation Switching the head-up display on/off
X
Press button :.
When the head-up display is switched on,
the display appears in the driver's field of
vision. 316
Displays and operationOn-board computer and displays
Safety systems
Display messages
Possible causes/consequences and
M
MSolutions !÷
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE‑SAFE ®
, HOLD function, hill start
assist, ESP ®
trailer stabilisation, Crosswind Assist, adaptive brake
lights, STEER CONTROL, Active Lane Keeping Assist and Active
Blind Spot Assist are temporarily unavailable.
BAS PLUS with Cross-Traffic Assist, PRE‑SAFE ®
Brake, PRE‑ SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
In addition, the ÷and! warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
For example, the on-board voltage may be insufficient.
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 Drive on carefully.
Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the multifunction display still shows the display message:
X Drive on carefully.
X Consult a qualified specialist workshop immediately. !÷
inoperative See inoperative See
Owner's Manual Owner's Manual ABS, ESP
®
, BAS, PRE‑SAFE ®
, HOLD function, hill start assist,
ESP ®
trailer stabilisation, Crosswind Assist, adaptive brake lights,
STEER CONTROL, Active Lane Keeping Assist and Active Blind
Spot Assist are unavailable due to a malfunction.
BAS PLUS with Cross-Traffic Assist, PRE‑SAFE ®
Brake, PRE‑SAFE ®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
In addition, the J,÷and! warning lamps may light up
in the instrument cluster. 336
Display messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions 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 Drive on carefully.
X Consult a qualified specialist workshop immediately. ÷
inoperative See inoperative See
Owner's Manual Owner's Manual ESP
®
, BAS, PRE ‑SAFE®
, HOLD function, hill start assist,
ESP ®
trailer stabilisation, Crosswind Assist, adaptive brake lights,
STEER CONTROL, Active Lane Keeping Assist and Active Blind
Spot Assist are unavailable due to a malfunction.
BAS PLUS with Cross-Traffic Assist, PRE‑ SAFE®
Brake, PRE ‑SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
The ÷ warning lamp also lights up in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus 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 Drive on carefully.
X Consult a qualified specialist workshop immediately. Display
messages
337On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions ÷
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual ESP
®
, BAS, PRE ‑SAFE®
, HOLD function, hill start assist,
ESP ®
trailer stabilisation, Crosswind Assist, adaptive brake lights,
STEER CONTROL, Active Lane Keeping Assist and Active Blind
Spot Assist are unavailable due to a malfunction.
BAS PLUS with Cross-Traffic Assist, PRE‑ SAFE®
Brake, PRE ‑SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
The ÷ warning lamp also lights up in the instrument cluster.
The self-diagnosis function, for example, may not be complete.
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 braking distance may thus 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 Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the multifunction display still shows the display message:
X Drive on carefully.
X Consult a qualified specialist workshop immediately. 338
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions T!
÷
inoperative See inoperative See
Owner's Manual Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS,
PRE ‑SAFE ®
, HOLD function, hill start assist, ESP ®
trailer stabili-
sation, Crosswind Assist, adaptive brake lights, STEER CONTROL, Active Lane Keeping Assist and Active Blind Spot Assist are
unavailable due to a malfunction.
BAS PLUS with Cross-Traffic Assist, PRE‑ SAFE®
Brake, PRE ‑SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
In addition, the ÷and! warning lamps light up in the
instrument cluster and a warning tone sounds.
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 an increased danger of skidding and risk of an accident.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. !
Turn on the igni‐ Turn on the igni‐
tion to release tion to release
the parking brake the parking brake The red
!indicator lamp lights up.
You attempted to release the electric parking brake while the igni-
tion was switched off.
X Switch the ignition on. !
Release parking Release parking
brake brake The red
!indicator lamp flashes and a warning tone sounds. A
condition for automatic release of the electric parking brake is not
fulfilled (Y page 220).
You are driving with the electric parking brake applied.
X Release the electric parking brake manually. The red
!indicator lamp flashes and a warning tone sounds.
You are making an emergency stop using the electric parking
brake (Y page 220). Display
messages
339On-board computer and displays Z
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 Safeguard the vehicle against rolling away (Y page 219).
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.
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 not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R defective power electronics (PLUG-IN HYBRID vehicles)
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 Safeguard the vehicle against rolling away (Y page 219).
X Consult a qualified specialist workshop. 354
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Stop
Stop
vehicle
vehicle Leave
Leave
engine running
engine running
Wait Transmission Wait Transmission
cooling cooling The transmission has overheated. Pulling away can be temporarily
impaired or not possible.
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 Wait until the display message disappears before pulling away. Auxiliary battery
Auxiliary battery
malfunction malfunction PLUG-IN HYBRID vehicles only:
The auxiliary battery for the transmission is no longer being
charged.
X Consult a qualified specialist workshop.
X Until then, set the transmission to position Pbefore you switch
off the engine.
X Before leaving the vehicle, apply the electric parking brake. 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 Safeguard the vehicle against rolling away (Y page 219).
X Close the bonnet. Active bonnet mal‐ Active bonnet mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction or because it has already been triggered.
X Consult a qualified specialist workshop. C C At least one door is open. A warning tone also sounds.
X Close all doors. Display
messages
371On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions _
Rear left seat Rear left seat
backrest not backrest not
locked locked
orRear
Rear
right seat back‐
right seat back‐
rest not locked rest not locked Vehicle with through-loading feature in the rear bench seat:
The backrest in the rear is not engaged on the left-hand and/or
right-hand side.
X Push the backrest back until it engages. _
Rear centre back‐ Rear centre back‐
rest not locked rest not locked Vehicle with through-loading facility in the rear compartment:
The centre rear seat backrest is not engaged.
X Push the backrest back until it engages. j
Check trailer Check trailer
hitch lock hitch lock The trailer tow-hitch is not operational.
A warning tone also sounds.
G WARNING
If the ball coupling is not in the locked position, 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 Safeguard the vehicle against rolling away (Y page 219).
X Uncouple the trailer and secure it against rolling away.
X Initiate a new swivelling procedure (Y page 304).
X When the display message disappears, re-couple the trailer.
If the multifunction display still shows the display message: X Do not re-couple the trailer.
X Check the ground clearance and continue driving without the
trailer.
X Consult a qualified specialist workshop immediately. j
Trailer coupling Trailer coupling
extending… extending… The ball coupling is swivelled out or in.
Only swivel the ball coupling in or out when the vehicle is station-
ary. No trailer may be coupled during the swivelling procedure. Do
not attempt to speed up, slow down or initiate the swivelling proc- ess using your hand, foot or other aids.
X Move the ball coupling of the trailer tow hitch to an operational
position (Y page 304).372
Display
messagesOn-board computer and displays