Display messages
Possible causes/consequences and
M SolutionsCollision Preven‐
tion Assist Inoper‐
ative COLLISION PREVENTION ASSIST PLUS is not available due to a mal-
function.
X Visit a qualified specialist workshop. Collision Preven‐
tion Assist Cur‐
rently Unavail.
See Oper. Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R The sensors in the front bumper are dirty.
R The function is impaired due to heavy rain or snow.
R The radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations
or other sources of electromagnetic radiation.
R The system is outside the operating temperature range.
R The on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out and COLLISION PREVENTION ASSIST is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle, paying attention to road and traffic
conditions.
X Secure the vehicle to prevent it from rolling away (Y page 138).
X Switch off the engine.
X Clean the sensors in the front bumper (Y page
267).
X Restart the engine. Lane Keeping
Assist Inoperative Lane Keeping Assist is faulty.
X Visit a qualified specialist workshop. Lane Keeping
Assist Currently
Unavail. See Oper.
Manual Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R The windshield is dirty in the camera's field of vision.
R Visibility is impaired due to heavy rain, snow or fog.
R There are no lane markings for an extended period.
R The lane markings are worn away, dark or covered, e.g. by dirt or
snow.
Once the causes listed above no longer apply, the display message
goes out and Lane Keeping Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle, paying attention to road and traffic
conditions.
X Secure the vehicle to prevent it from rolling away (Y page
138).
X Clean the windshield.222
Display messages (vehicles with steering wheel buttons)
On-board computer and displays
Display messages
Possible causes/consequences and
M SolutionsCruise Control
- - - mph A condition for activating cruise control has not been met.
You have tried to store a speed below
20 mph (30 km/h) for exam-
ple.
X If conditions permit, drive faster than 20 mph (30 km/h) and
store the speed.
X Check the activation conditions for cruise control (Y page
147).Blind Spot Assist
Inoperative Blind Spot Assist is faulty.
X Visit a qualified specialist workshop. Blind Spot Assist
Currently Unavail.
See Operator's Man‐
ual Blind Spot Assist is temporarily inoperative. Possible causes:
R You have attached a trailer.
R The sensors in the rear bumper are dirty.
R The function is impaired due to heavy rain or snow.
R The radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations
or other sources of electromagnetic radiation.
R The system is outside the operating temperature range.
Once the causes listed above no longer apply, the display message
goes out and Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle, paying attention to road and traffic
conditions.
X Secure the vehicle to prevent it from rolling away ( Y page
138).
X Switch off the engine.
X Clean the sensors in the rear bumper (Y page
267).
X Restart the engine. Display messages (vehicles with steering wheel buttons)
223
On-board computer and displays Z
Tires
Display messages
Possible causes/consequences and
M SolutionsAdjust Tire Pres‐
sure The tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great.
X Check the tire pressure at the next opportunity (Y page 285).
X If necessary, correct the tire pressure.
X Restart the tire pressure monitor ( Y page
288).Check Tires An additional warning tone sounds.
The tire pressure in one or more tires has dropped significantly. The
display shows the wheel position.
G WARNING
Underinflated tires pose the following risks:
R The tires may burst, especially as the load and vehicle speed
increase.
R The tires may wear excessively and/or unevenly, which may
greatly impair tire traction.
R The handling as well as steering and braking characteristics may
be severely affected.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions while doing so.
X Secure the vehicle to prevent it from rolling away (Y page
138).
X Check the tires and, if necessary, change the wheel
(Y page
297).
X Check the tire pressure (Y page
285).
X If necessary, correct the tire pressure. Warning Tire Mal‐
function The tire pressure in one or more tires has dropped suddenly. The
display shows the wheel position.
G WARNING
Driving with a flat tire poses a risk of the following hazards: R A flat tire affects the ability to steer or brake the vehicle.
R You could then lose control of the vehicle.
R Continued driving with a flat tire 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
maneuvers. Pay attention to the traffic conditions while doing so.
X Secure the vehicle to prevent it from rolling away (Y page
138).
X Check the tires and, if necessary, change the wheel
(Y page
297).224
Display messages (vehicles with steering wheel buttons)
On-board computer and displays
Display messages
Possible causes/consequences and
M SolutionsTire Pressure Moni‐
tor Currently
Unavailable Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.
The tire pressure monitor restarts automatically as soon as the
problem has been solved. Wheel Sensor(s)
Missing There is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not shown in the display.
X Have the faulty tire pressure sensor replaced at a qualified spe-
cialist workshop. Tire Pressure Moni‐
tor Inoperative No
Wheel Sensors The wheels installed do not have suitable tire pressure sensors. The
tire pressure monitor is deactivated.
X Install wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving
for a few minutes. Tire Press. Moni‐
tor Inoperative The tire pressure monitor is malfunctioning.
X Visit a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
M SolutionsShift to 'P' or
'N' to Start Engine You have attempted to start the engine in transmission position
k
or h.
X Shift the transmission to position j or i.Auxiliary Battery
Malfunction The auxiliary battery for the transmission is no longer being
charged.
X Visit a qualified specialist workshop. Apply Brake to
Shift from 'P' You attempted to shift the transmission to position
h, k or i
without depressing the brake pedal.
X Depress the brake pedal. Perm. N Activated
Risk of Rolling An additional warning tone sounds. The transmission has been shif-
ted to position i when the vehicle is coasting or being driven.
X Stop the vehicle by depressing the brake pedal and when the
vehicle is stationary shift the transmission to position j.
X Continue driving by shifting the transmission to position h or
k. Risk of Rolling:
Transmission Not
in P An additional warning tone sounds. The driver's door is open and
the transmission is in position k, i or h.
X Shift the transmission to position j.
X Secure the vehicle to prevent it from rolling away ( Y page 138).Display messages (vehicles with steering wheel buttons)
225
On-board computer and displays Z
Safety systems
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M Solutions$J
ò
N $ (USA only) or J (Canada only): the ABS and brake warning lamps
are lit while the engine is running.
EBD is unavailable due to a malfunction. ABS, BAS, hill start assist and ESP
®
as
well as its driving safety systems, for example, are therefore also unavailable.
ATTENTION ASSIST is deactivated and other driving systems could be automati-
cally deactivated.
G WARNING
The brake system continues to function normally, but without the functions lis-
ted above. The wheels could therefore lock prematurely if you brake hard, for
example.
This causes steerability and braking to be greatly impaired. The braking distance
may increase in emergency braking situations.
If ESP ®
is not operational, ESP ®
will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
X Switch the engine off, wait briefly and start the engine again.
X Check if the display message has disappeared and ESP ®
is operational.
X If the display message continues to be displayed:
R Drive on with care.
R Visit a qualified specialist workshop immediately. $J
N The red
$ (USA only) or J (Canada only) brake system warning lamp is
lit while the engine is running. An additional warning tone sounds.
There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
Braking performance can 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 under any circumstances.
X Secure the vehicle to prevent it from rolling away ( Y page 138).
X Do not add brake fluid. Adding more will not remedy the malfunction.
X Consult a qualified specialist workshop.
X Observe the display messages. Indicator and warning lamps in the instrument cluster
229
On-board computer and displays Z
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M Solutionså
N The yellow ESP
®
OFF warning lamp is lit while the engine is running or the
ECO start/stop function is activated.
ESP ®
is deactivated. ESP ®
trailer stabilization and Crosswind Assist are deacti-
vated.
G WARNING
If ESP ®
is deactivated, vehicle stabilization assistance is significantly reduced.
There is an increased risk of skidding and accidents.
X Reactivate ESP ®
.
In rare cases , it may be best to deactivate ESP ®
(Y page
68).
X Adapt your driving style to suit the weather and road conditions.
If ESP ®
cannot be activated:
X Drive on with care.
X Have ESP ®
checked at a qualified specialist workshop. 6
N The red restraint system warning lamp is lit while the engine is running.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
X Observe the display messages.
X Drive on with care.
X Have the restraint system and its components checked immediately at a
qualified specialist workshop.
Further information on the restraint system and its components can be found
under "Occupant safety"
(Y page 46).232
Indicator and warning lamps in the instrument cluster
On-board computer and displays
Engine
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M Solutions;
N The yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction in the following vehicle systems:
R in the engine management
R in the transmission management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with a gasoline engine)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop. 6
N The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped to the reserve range.
X Refuel at the nearest gas station. ?
N The red coolant warning lamp comes on while the engine is running.
On vehicles without steering wheel buttons, the coolant temperature gauge is at
the start of the bar display
(Y page 178).
On vehicles with steering wheel buttons, the coolant temperature gauge is at
the start of the scale in the instrument cluster ( Y page 40).
The temperature sensor for the coolant temperature gauge is faulty.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving under any circumstances.
X Secure the vehicle to prevent it from rolling away (Y page
138).
X Consult a qualified specialist workshop. Indicator and warning lamps in the instrument cluster
233
On-board computer and displays Z
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
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 display messages.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle to prevent it from rolling away (Y page 138).
X Exit the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and add coolant, observing the warning notes
(Y page
253).
X If you have to add coolant more frequently, have the engine cooling system
checked.
X Make sure that the air supply to the radiator is not obstructed, by frozen
slush for example.
X Check the coolant temperature:
R using the display in the on-board computer on vehicles without steering
wheel buttons ( Y page
178)
R using the analog display in the instrument cluster on vehicles with steering
wheel buttons ( Y page 40)
X Do not start the engine again until the coolant temperature is below the maxi-
mum value specified below. The engine could otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
Avoid heavy loads on the engine, e.g. driving in mountainous terrain, and
stop-start traffic.
Under normal driving conditions and at the correct coolant level, the coolant
temperature display may rise to the letter H or to the red mark.?
N The red coolant warning lamp comes on while the engine is running. An addi-
tional warning tone sounds.
The coolant temperature has exceeded the maximum value specified below. 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 adequately and could become damaged.
Never drive with an overheated engine. Otherwise, fluids which may have leaked
into the engine compartment could catch fire.
In addition, steam from an overheated engine can cause serious burns, which
can occur just by opening the hood.
There is a risk of injury.
X Observe the display messages.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. 234
Indicator and warning lamps in the instrument cluster
On-board computer and displays