Display messages
Possible causes/consequences and
M
MSolutions j
Check Check
trailer
trailer hitch
hitch
lock
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 traffic
conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 155).
X Engage the ball coupling of the trailer tow hitch in the end position
(Y page 197). &
inoperative inoperative
Battery
Battery
Low
Low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 126).
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 Refuel inoperative Refuel
vehicle vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot be
switched on (Y page 126).
X Refuel at the nearest filling station. &
inoperative inoperative
See
SeeOwn‐
Own‐
er's Man.
er's Man. The auxiliary heating is temporarily malfunctioning or faulty.
If the vehicle is on a level surface and the engine has cooled down:
X Make up to four attempts to switch on the auxiliary heating, waiting
several minutes between each attempt (Y page 126).
If the auxiliary heating does not switch on:
X Consult a qualified specialist workshop. Ð
Power steering mal‐ Power steering 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 steering force
required.
If you are able to steer safely:
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If you are unable to steer safely:
X Do not drive on.
X Consult a qualified specialist workshop. Display
messages
245On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions 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 155).
X Do not drive on.
X Consult a qualified specialist workshop. _
Before Before
starting
starting the
the
engine, turn the
engine, turn the
steering wheel. steering 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
Telephone
No
Noservice
service Your vehicle is outside the mobile phone network provider's trans-
mitter/receiver range.
X Wait until the mobile phone operational readiness symbol appears
in the multifunction display. ¥
Top up washer fluid Top up washer fluid The washer fluid level in the washer fluid reservoir has dropped below
the minimum.
X Top up the washer fluid (Y page 284).Wiper malfunction‐
Wiper malfunction‐
ing ing The windscreen wipers are defective.
X Consult a qualified specialist workshop. Hazard warning
Hazard warning
lamps malfunction‐ lamps malfunction‐
ing ing The hazard warning lamps are faulty.
X Consult a qualified specialist workshop. Key
Display messages
Possible causes/consequences and
M
MSolutions Â
Key Key
does
does not
notbelong
belong
to vehicle
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 Consult a qualified specialist workshop. Â
Change Change
key
keybatteries
batteries The key battery is discharged.
X Change the battery(Y page 79).246
Display
messagesOn-board computer and displays
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 cen-
trally 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 155).
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 155).
X Insert the key into the ignition lock and bring into key mode. Â
Key not detected Key not detected
(white display message) 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 Remove
starting
starting but‐
but‐
ton,
ton, then
theninsert
insert key
key The key is continually undetected.
The key detection function has a temporary malfunction or is faulty. A
warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired posi-
tion.
X Consult 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. Wa
rning and indi cator lamps in the instrument cluster
247On-board computer and displays Z
Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
Only for certain countries: the red seat belt warning lamp lights up for 6 seconds
after the engine starts.
The seat belt warning lamp reminds the driver and front passenger to fasten their
seat belts.
X Fasten your seat belt (Y page 43).ü
N
Only for certain countries: the red seat belt warning lamp lights up after the
engine starts. In addition, a warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 43).
The warning tone ceases. ü
N
The red seat belt warning lamp lights up after the engine starts, as soon as the
driver's or the front-passenger door is closed.
The driver or passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 43).
The warning lamp goes out.
There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow them in a secure
place.
The warning lamp goes out. ü
N
The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or passenger has not fastened their seat belt. At the same time, you are
driving faster than 25 km/h or have briefly driven faster than 25 km/h.
X Fasten your seat belt (Y page 43).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. At the same time, you are driving
faster than 25 km/h or have briefly driven faster than 25 km/h.
X Remove the objects from the front-passenger seat and stow them in a secure
place.
The warning lamp goes out and the intermittent warning tone ceases. 248
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The red brake system warning lamp lights up while the engine is running. A
warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic conditions. Do
not continue driving.
X Secure the vehicle against rolling away (Y page 155).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. J
N
The red brake system warning lamp lights up while the engine is running. A
warning tone also sounds.
There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
Braking efficiency may be impaired.
There is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic conditions. Do
not continue driving.
X Secure the vehicle against rolling away (Y page 155).
X Do not top up the brake fluid. Topping up will not correct the fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. Warning and indicator lamps in the instrument cluster
249On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
N
The yellow ABS warning lamp lights up while the engine is running.
ABS (Anti-lock Braking System) has been deactivated due to a fault. BAS (Brake
Assist), Active Brake Assist, ESP ®
(Electronic Stability Program), ESP ®
trailer sta-
bilisation, the HOLD function, hill start assist, the adaptive brake lights and
PRE‑SAFE ®
are also deactivated, for example.
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 impaired as a result. The braking distance may increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If the ABS control unit is faulty, there is also a possibility that other systems, such as the navigation system or the automatic transmission, will be unavailable. 250
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions !
N
The yellow ABS warning lamp lights up while the engine is running.
ABS is temporarily unavailable. BAS, Active Brake Assist, ESP ®
, ESP ®
trailer sta-
bilisation, 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 if you brake hard, for exam-
ple.
The steerability and braking characteristics may be severely impaired as a result. 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 steering 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 Consult a qualified specialist workshop immediately. !
N
The yellow ABS warning lamp lights up while the engine is running. A warning
tone also sounds.
EBD is faulty. ABS, BAS, Active Brake Assist, ESP ®
, ESP ®
trailer stabilisation, the
HOLD function, hill start assist, the adaptive brake lights and PRE‑SAFE ®
, for
example, are also unavailable.
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 if you brake hard, for exam-
ple.
The steerability and braking characteristics may be severely impaired as a result. The braking distance may increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. Warning and indicator lamps in the instrument cluster
251On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
֌
J
N
The red brake system warning lamp and the yellow ABS, ESP ®
and ESP ®
OFF
warning lamps are lit while the drive system is running.
ABS and ESP ®
are malfunctioning. BAS, Active Brake Assist, EBD, PRE ‑SAFE®
, the
HOLD function, hill start assist, the adaptive brake lights and ESP ®
trailer stabili-
sation, for example, are also unavailable.
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 if you brake hard, for exam-
ple.
The steerability and braking characteristics may be severely impaired as a result. The braking distance may increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
Increased risk of skidding and/or accident!
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. ÷
N
The yellow ESP ®
warning lamp flashes while the vehicle is in motion.
ESP ®
or traction control has engaged due to a risk of skidding or because at least
one wheel has started to spin.
Cruise control or Distance Pilot DISTRONIC is deactivated.
X Only depress the accelerator pedal as far as necessary when pulling away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
In exceptional cases (Y page 71) it may be better to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 70). 252
Warning and indicator lamps in the instrument clusterOn-board computer and displays