Page 269 of 373

Display messages Possible causes/consequences and
M Solutions
With the Hold function activated, you have either:
R
opened the driver's doo rand released the sea tbelt or
R switched off the engine or
R opened the bonnet
At one may also sound at regular intervals. The tone becomes
louder if you attempt to lock the vehicle.
You cannot start the engine.
X Shift the transmission to position P.
You can restart the engine. N The boot lid is open.
X
Close the boot lid. M G
Risk of accident
Vehicles with an anti-theft alarm system: the bonnet is open. 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 Apply the parking brake.
X Close the bonnet. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Front left seat
backr. not locked
or
Front right seat backr. not
locked The driver's or front-passenger seat backres
tis not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. Check trailer
hitch lock G
Risk of accident
Vehicles with a retractable trailer coupling:
The trailer tow hitch is not correctly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 201).266
Display messagesOn-board computer and displays
Page 270 of 373

Display messages Possible causes/consequences and
M Solutions
Pwr. steering
malfunc. G
Risk of accident
The powe rsteering assistance is faulty. You will need to use more
force to steer.
Aw arning tone also sounds.
X Chec kwhether 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. 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 304).Vehicle (12-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
To start engine,
shift to either P
or N You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. P
Select Park (P) You have switched off the engine with the Start/Stop button and
opened the driver's door.
You wanted to lock the vehicle.
Aw
arning tone also sounds.
or
You have switched off the engine with the Start/Stop butto nand
opened the driver's door with the transmission in position N.
X Shift the transmission to position P. While the HOLD functio
norDISTRONIC PLUS is active, you have:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet
At one may also sound at regular intervals. The tone becomes
louder if you attempt to lock the vehicle.
You cannot start the engine.
X Shift the transmission to position P.
You can restart the engine. Display messages
267On-board computer and displays Z
Page 271 of 373

Display messages Possible causes/consequences and
M Solutions
N The boo
tlid is open.
X Close the boot lid. M G
Risk of accident
The bonnet is open .Awarning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Close the bonnet.
If the active bonnet (pedestrian protection) has been triggered:
X Reset the bonnet (Y page 300).
X Close the bonnet. Active bonnet
malfunction See
Owner's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction.
X
Visit a qualified specialist workshop. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Front left seat
backrest not locked
or
Front right seat backrest not
locked The driver's or front-passenger seat backres
tis not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. j
Check trailer
hitch lock G
Risk of accident
The trailer tow hitch is not correctly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 201).268
Display messagesOn-board computer and displays
Page 272 of 373

Display messages Possible causes/consequences and
M Solutions
D
Power
steering mal‐
function See Own‐
er's Manual G
Risk of accident
The powe rsteering assistance is faulty.
You will need to use more force to steer.
Aw arning tone also sounds.
X Chec kwhether 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. &
inoperative Bat‐
tery low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 128).
X Drive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
inoperative
Refuel
vehicle The fuel level in the fuel tank is too low. The auxiliary heating can-
not be switched on (Y page 128).
X Refuel at the nearest filling station. &
inoperative See
Owner's Man. The auxiliary heating has a temporary malfunction or is faulty.
X When the vehicle is on alevel 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 128).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. Telephone No
Service 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
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 304). Display messages
269On-board computer and displays Z
Page 273 of 373

Key (4-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. +
Replace key The key needs to be replaced.
X
Visit a qualified specialist workshop. +
Change battery The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries ( Ypage 80). Key not detected
(Red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe 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 Apply the parking brake.
X Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
Aw
arning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Operate the vehicle with the key in the ignition lock if necessary. Key not detected
(White display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
X Change the location of the key with the KEYLESS-GO functions
in the vehicle.
X Operate the vehicle with the key in the ignition lock if necessary. +
Key still in vehi‐
cle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. 270
Display messagesOn-board computer and displays
Page 274 of 373

Display messages Possible causes/consequences and
M Solutions
+
Insert key KEYLESS-GO is temporarily malfunctioning or is defective.
Awarn-
ing tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visi taqualified specialist workshop. Close doors
to lock veh. At least one door is open.
Awarning tone also sounds.
X Close all doors and loc kthe vehicle again. Key (12-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
Â
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. Â
Replace key The key needs to be replaced.
X Visit a qualified specialist workshop. Â
Change key batter‐
ies The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries (Y page 80).Â
Key not detected
(Red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe 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 Apply the parking brake.
X Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
Aw
arning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Operate the vehicle with the key in the ignition lock if necessary. Display messages
271On-board computer and displays Z
Page 275 of 373

Display messages Possible causes/consequences and
M Solutions
Â
Key not detected
(White display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X
Change the location of th ekey with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
X Change the location of the key with the KEYLESS-GO functions
in the vehicle.
X Operate the vehicle with the key in the ignition lock if necessary. Â
Key still in vehi‐
cle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. Â
Remove starting
button, then
insert key KEYLESS-GO is temporarily malfunctioning or is defective.
Awarn-
ing tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visi taqualified specialist workshop. Â
Close doors to
lock vehicle At least one door is open.
Awarning tone also sounds.
X Close all doors and loc kthe vehicle again. 272
Display messagesOn-board computer and displays
Page 276 of 373

Warning and indicator lamps in the instrument cluster
Seat belt
Problem Possible causes/consequences and
M Solutions
7
Only for certain coun-
tries: the red sea
tbelt
warning lamp lights up
for six seconds after
the engine starts. The seat belt warning lamp reminds the driver and fron
tpassenger
to fasten their seat belts.
X Faste nyour seat belt (Y page 51). 7
Only for certain coun-
tries: the red seat belt
warning lamp lights up
after the engine starts.
In addition, a warning
tone sounds for up to
six seconds.
G
Risk of injury
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 51).
The warning tone ceases. 7
The red seat belt warn-
ing lamp lights up after
the engine starts, as
soon as the driver's or
the front-passenger
door is closed. G
Risk of injury
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 51).
The warning lamp goes out. G
Risk of injury
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. Warning and indicator lamps in the instrument cluster
273On-board computer and displays Z