Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top up coolant See Top up coolant See
Owner's Manual Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 292).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist workshop. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue driving
to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving
in mountainous terrain and stop-start traffic. ?
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 traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
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 otherwisebe damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, consult a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. 238
Display messagesOn-board computer and displays
Driving systems
Display messages
Possible causes/consequences and
M
MSolutions À
Attention Assist: Attention Assist:
Take a break! Take a break! Based on certain criteria, ATTENTION ASSIST has detected 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 time so that you get
enough rest. À
Attention Assist Attention Assist
inoperative inoperative ATTENTION ASSIST is inoperative.
X Consult a qualified specialist workshop. Traffic
Traffic
Sign
SignAssist
Assist
currently unavaila‐
currently unavaila‐
ble ble See
SeeOwner's
Owner's Man‐
Man‐
ual
ual Traffic Sign Assist is temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational, the display message disappears.
Traffic Sign Assist is operational again. Traffic Traffic
Sign
SignAssist
Assist
inoperative
inoperative Traffic Sign Assist is faulty.
X Consult a qualified specialist workshop. ë
Off Off The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later (Y page 177). The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 177). Display
messages
241On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Lane
Lane
Keeping
Keeping Assist
Assist
currently unavaila‐
currently unavaila‐
ble ble See
SeeOwner's
Owner's Man‐
Man‐
ual
ual orActive LaneActive Lane
Keeping Assist cur‐
Keeping Assist cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual Lane Keeping Assist or Active Lane Keeping Assist is deactivated and
temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
R there have been no lane markings for an extended period
R the lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist or Active Lane Keeping Assist is operational
again.
If the display message does not disappear:
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 157).
X Clean the windscreen. Lane Lane
Keeping
Keeping Assist
Assist
inoperative
inoperativeorActive Active
Lane
Lane Keeping
Keeping Assist
Assist
inoperative
inoperative Lane Keeping Assist or Active Lane Keeping Assist is faulty.
X Consult a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual orActive BlindActive Blind
Spot Assist cur‐
Spot Assist cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inoperative.
Possible causes:
R the radar sensor system is outside the operating temperature range
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
The yellow 9indicator lamps also light up in the exterior mirrors.
Once the causes listed above no longer apply, the display message
goes out.
Blind Spot Assist or Active Blind Spot Assist is operational again.
If the display message does not disappear:
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 157).
X Restart the engine. Blind Spot Assist Blind Spot Assist
not available when not available when
towing a trailer towing a trailer
See Owner's Manual See Owner's Manual Blind Spot Assist or Active Blind Spot Assist is deactivated while tow-
ing a trailer.
You have established the electrical connection between the trailer and
your vehicle.
X Press aon the steering wheel to confirm the display message. 242
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions DTR+: steering
DTR+: steering
assist. currently assist. currently
unavailable unavailable
See
SeeOwn‐
Own‐
er's Manual
er's Manual Steering Assist and Stop&Go Pilot are temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
R there have been no lane markings for an extended period
R the lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
goes out.
Steering Assist and Stop&Go Pilot are operative again.
If the display message does not disappear:
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 157).
X Clean the windscreen. DTR+: steering DTR+: steering
assistant inopera‐ assistant inopera‐
tive tive Steering Assist and Stop&Go Pilot are faulty.
However, the DISTRONIC PLUS functions are still available.
A warning tone also sounds.
X Consult a qualified specialist workshop. Cruise control and Cruise control and
SPEEDTRONIC inoper‐ SPEEDTRONIC inoper‐
ative ative SPEEDTRONIC and cruise control are malfunctioning.
A warning tone also sounds.
X Consult a qualified specialist workshop. SPEEDTRONIC suspen‐ SPEEDTRONIC suspen‐
ded ded If you depress the accelerator pedal beyond the pressure point (kick-
down), SPEEDTRONIC is switched to passive mode.
The speed limitation is not active.
X Drive slower than the stored speed and without kickdown.
X Call up the last speed stored again.
or X Set a new speed.
When the display message disappears, the speed limitation is active. SPEEDTRONIC Limit SPEEDTRONIC Limit
--- km/h --- km/h SPEEDTRONIC cannot be activated, as the activation conditions have
not all been met.
X Check the activation conditions for SPEEDTRONIC (Y page 165).Cruise control
Cruise control
- - - km/h - - - km/h A condition for activating cruise control has not been met.
You have tried to store a speed below 30 km/h, for example.
X If conditions permit, drive faster than 30 km/h and store the speed.
X Check the activation conditions for cruise control (Y page 163). Display
messages
245On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Cruise control off
Cruise control off Cruise control has been deactivated.
If a warning tone also sounds, cruise control has deactivated auto-
matically (Y page 163). 120 km/h 120 km/h
Maximum Maximum
speed
speedexcee‐
excee‐
ded
ded Only for certain countries: the maximum speed has been exceeded.
In addition, the multifunction display shows
120 km/h! 120 km/h!.
X Drive more slowly. Tyres
Display messages
Possible causes/consequences and
M
MSolutions Tyre pressure
Tyre pressure
Check tyres Check tyres The tyre pressure loss warning system has detected a significant loss
in pressure.
A warning tone also sounds.
Possible causes:
R you have changed the positions of the wheels and tyres or fitted new
wheels and tyres
R the tyre pressure in one or more tyres has dropped
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed
increase
R the tyres may wear excessively and/or unevenly, which may greatly
impair tyre traction
R the driving characteristics, as well as steering and braking, may be
greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Safeguard the vehicle against rolling away (Y page 157).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 306).
X Check the tyre pressures and, if necessary, correct the tyre pres-
sure.
X Restart the tyre pressure loss warning system when the tyre pres-
sure is correct (Y page 326). Check Check
tyre
tyrepressures
pressures
then restart Run
then restart Run
Flat Indicator Flat Indicator The tyre pressure loss warning system generated a display message
and has not been restarted since.
X Set the correct tyre pressure in all four tyres.
X Restart the tyre pressure loss warning system (Y page 326).Run Flat Indicator Run Flat Indicator
inoperative inoperative The tyre pressure loss warning system is faulty.
X Consult a qualified specialist workshop. 246
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Rectify
Rectify
tyre pressure tyre pressure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure difference between the wheels is too great.
X Check the tyre pressures at the next opportunity (Y page 326).
X If necessary, correct the tyre pressure.
X Restart the tyre pressure monitor (Y page 328).Check
Check
tyre(s)
tyre(s) The tyre pressure in one or more tyres has dropped significantly. The
wheel position is shown in the multifunction display.
A warning tone also sounds.
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed
increase
R the tyres may wear excessively and/or unevenly, which may greatly
impair tyre traction
R the driving characteristics, as well as steering and braking, may be
greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Safeguard the vehicle against rolling away (Y page 157).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 306).
X Check the tyre pressure (Y page 326).
X If necessary, correct the tyre pressure. Warning Warning
tyre defect tyre defect The tyre pressure in one or more tyres has dropped suddenly. The
wheel position is shown in the multifunction display.
G WARNING
If you drive with a flat tyre, there is a risk of the following hazards: R a flat tyre affects the ability to steer or brake the vehicle
R you could lose control of the vehicle
R continued driving with a flat tyre will cause excessive heat build-up
and possibly a fire
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Safeguard the vehicle against rolling away (Y page 157).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 306). Display
messages
247On-board computer and displays Z
Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The yellow brake system warning lamp lights up while the engine is running.
G WARNING
The brake system is malfunctioning and the braking characteristics may be affec- ted.
There is a risk of an accident.
X If the multifunction display shows a display message, please observe this.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. J
N
The red brake system warning lamp comes on while the vehicle is moving. A
warning tone also sounds.
You are driving with the parking brake applied.
X Release the parking brake.
The warning lamp goes out and the warning tone ceases. J
N
The red brake system warning lamp is lit 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 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 Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. J
N
The red brake system warning lamp is lit while the engine is running. A warning
tone also sounds.
G WARNING
There is insufficient brake fluid in the brake fluid reservoir.
Braking efficiency may be impaired.
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. Do not continue driving under any circumstances.
X Safeguard the vehicle against rolling away (Y page 157).
X Do not top up the brake fluid. Topping up will not rectify 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
255On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
The red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunctioning.
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 Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 292).
X If you have to top up the coolant frequently, have the engine cooling system
checked.
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 coolant temperature is below 120 †. The
engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving in moun-
tainous terrain and stop-start traffic. ?
N
The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature has exceeded 120 †. The airflow to the engine radiator
may be blocked or the coolant level may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
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 Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Leave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and top up the coolant, observing the warning notes
(Y page 292).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 260
Warning and indicator lamps in the instrument clusterOn-board computer and displays