Page 310 of 466

Display messages
Possible causes/consequences and
0050
0050Solutions Blind Spot Assist
Blind Spot Assist
Currently Unavail‐ Currently Unavail‐
able See Opera‐ able See Opera‐
tor's Manual tor's Manual
or
Active Blind Spot
Active Blind Spot
Assist Currently Assist Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative. Possible causes are:
R the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 0063indicator lamps also light up in the exterior mir-
rors.
When the causes stated above no longer apply, the display mes-
sage disappears.
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 Secure the vehicle against rolling away (Y page 182).
X Clean the sensors (Y page 375).
X Restart the engine. Blind Spot Assist or Active Blind Spot Assist is deactivated while
towing a trailer.
You have established the electrical connection between the trailer
and your vehicle.
X Press 0076on the steering wheel to confirm the display mes-
sage. Blind Spot Assist Blind Spot Assist
Inoperative Inoperative
or
Active Blind Spot
Active Blind Spot
Assist Inoperative Assist Inoperative Blind Spot Assist or Active Blind Spot Assist is defective.
The yellow
0063indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Assist Can‐ Park Assist Can‐
celed celed The driver's door is open and the driver's seat belt has not been
fastened.
X Repeat the parking process with the seat belt fastened and the
driver's door closed. You have inadvertently touched the multifunction steering wheel
while steering intervention was active.
X While steering intervention is active, make sure that the multi-
function steering wheel is not touched unintentionally. 308
Display
messagesOn-board computer and displays
Page 320 of 466

Display messages
Possible causes/consequences and
0050
0050Solutions The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
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 182).
X Operate the vehicle with the SmartKey in the ignition lock. 00AF
Key Not Detected Key Not Detected
(white display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X Change the location of the SmartKey with the KEYLESS-GO
functions in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the SmartKey in the ignition lock. 00AF
Remove Remove
'Start'
'Start' But‐
But‐
ton and Insert Key
ton and Insert Key KEYLESS-GO is temporarily malfunctioning or is defective. A warn-
ing tone also sounds.
X Insert the SmartKey into the ignition lock and turn it to the
desired position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Safety
Seat belts Problem
Possible causes/consequences and
0050 0050Solutions 00E9
After starting the
engine, the red seat
belt warning lamp lights
up for 6 seconds. The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X Fasten your seat belt (Y page 48).00E9
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a warn-
ing tone sounds for up
to 6 seconds. The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 48).
The warning tone ceases. 318
Wa
rning and indi cator lamps in the instrument clusterOn-board computer and displays
Page 321 of 466

Problem
Possible causes/consequences and
0050
0050Solutions 00E9
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.
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 48).
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. 00E9
The red seat belt warn-
ing lamp flashes and an
intermittent audible
warning sounds. The driver or front passenger has not fastened their seat belt. The
vehicle is being driven faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph (25 km/h).
X Fasten your seat belt (Y page 48).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. The vehicle is being
driven faster than 15 mph (25 km/h) or has briefly been driven
faster than 15 mph (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. Warning and indicator lamps in the instrument cluster
319On-board computer and displays Z
Page 324 of 466

Problem
Possible causes/consequences and
0050
0050Solutions 0025
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, BAS PLUS, ESP
®
,
EBD (electronic brake force distribution), PRE‑ SAFE®
,
PRE‑SAFE ®
Brake, COLLISION PREVENTION ASSIST, the HOLD
function, hill start assist, and ESP ®
trailer stabilization, for exam-
ple, are also deactivated.
ATTENTION ASSIST is deactivated.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
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 example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is a risk of an accident.
X Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (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 Visit a qualified specialist workshop. 322
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 327 of 466

Problem
Possible causes/consequences and
0050
0050Solutions 00E500BB
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilization are temporarily unavailable.
COLLISION PREVENTION ASSIST, BAS PLUS and
PRE‑SAFE ®
Brake may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (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 Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
325On-board computer and displays Z
Page 328 of 466
Problem
Possible causes/consequences and
0050
0050Solutions 0049
(USA only)
0024 (Canada only)
The red electric parking brake indicator lamp
flashes or lights up
and/or
0024
warning lamp for the
electric parking brake
lights up. X
Observe the additional display messages in the multifunction
display. 0075
The red restraint sys-
tem warning lamp is lit
while the engine is run-
ning.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist
workshop immediately.
For further information about the restraint system, see
(Y page 44). 326
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 329 of 466

Engine
Problem
Possible causes/consequences and
0050
0050Solutions 00B9
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with gasoline engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified special-
ist workshop as soon as the yellow Check Engine warning lamp
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 180).
X Start the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked. 00B6
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 00B6
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the
00B9
Check Engine warning
lamp may light up. The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist work-
shop. Warning and indicator lamps in the instrument cluster
327On-board computer and displays Z
Page 330 of 466
Problem
Possible causes/consequences and
0050
0050Solutions 00AC
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. The temperature sensor for the coolant temperature gage is defec-
tive.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
X Secure the vehicle against rolling away (Y page 182).
X Consult a qualified specialist workshop. 328
Warning and indicator lamps in the instrument clusterOn-board computer and displays