Page 259 of 420
Display messages Possible causes/consequences and
M Solutionsb
Malfunction See
Operator's Manual The exterior lighting is defective.
X
Visit a qualified specialist workshop. b
Auto
Lamp Function
Inoperative The light sensor is defective.
X
Visit a qualified specialist workshop. b
Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X
Turn the light switch to Ã.Adaptive Highbeam
Assist Inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Highbeam
Assist Currently
Unavailable See
Operator's Manual Adaptive Highbeam Assist is deactivated and temporarily
inoperative. Possible causes are:
R
the windshield in the camera's field of vision is dirty.
R visibility is impaired due to heavy rain, snow or fog.
X Clean the windshield.
If the system detects that the camera is fully operational again,
the Adaptive Highbeam Assist Now Available message is
displayed.
Adaptive Highbeam Assist is operational again. Display messages
257
On-board computer and displays Z
Page 260 of 420
Engine
Display messages Possible causes/consequences and
M Solutions+
Check Coolant
Level See
Operator'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 Add coolant, observing the warning notes before doing so
(Y page 331).
X If coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop. ? The fan motor is faulty.
X
At coolant temperatures under 248 ‡(120 †),
drive to the next
qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic. ?
Coolant Too Hot
Stop Vehicle Turn
Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 175).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is under 248 ‡ (120
†).
Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to
248 ‡ (120 †).258
Display messages
On-board computer and displays
Page 261 of 420
Display messages Possible causes/consequences and
M Solutions# The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R
a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 175).
X Open the hood.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do
not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Visit a qualified specialist workshop. 4
Check Engine Oil
At Next Refueling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
X
Check the oil level when next refueling, at the latest
(Y page 330).
X If necessary, add engine oil ( Y page 330).
X Have the engine checked at a qualified specialist workshop if
engine oil needs to be added more often than usual.
! Avoid long journeys with too little engine oil. The engine will
otherwise be damaged.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
www.mbusa.com (USA only). Display messages
259
On-board computer and displays Z
Page 263 of 420
Display messages Possible causes/consequences and
M SolutionsØ
Check
Additive See
Operator's Manual The DEF tank is empty.
X
Have the DEF tank filled as soon as possible at a qualified
specialist workshop
(Y page 173).Ø
Remaining Starts:
16 The DEF level has fallen to a minimum.
X
Have the DEF tank filled immediately at a qualified specialist
workshop ( Y page 173). Driving systems
Display messages Possible causes/consequences and
M SolutionsÀ
Attention Assist:
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 you get
enough rest. À
Attention Assist
Inoperative ATTENTION ASSIST is inoperative.
X
Visit a qualified specialist workshop. ¨or°
Vehicle Rising Your vehicle is adjusting to the level you have selected.
¨or°
Vehicle Rising
Wait Briefly The vehicle level is too low when the vehicle is stationary. A
warning tone also sounds.
X
Do not pull away.
The vehicle level is set when the display message disappears. ¨or°
STOP Car Too Low You have pulled away while the vehicle level is still too low.
AIRMATIC sets the vehicle to the selected level after a short
period.
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 175).
X Wait until the display message disappears before pulling away. Display messages
261On-board computer and displays Z
Page 264 of 420
Display messages Possible causes/consequences and
M SolutionsAIRMATIC is defective. A warning tone also sounds.
X
Do not drive faster than 50 mph (80km/h).
X Make only slight steering movements. Otherwise, the front
fender
or the tires could be damaged if the steering movement
is too large.
X Listen for scraping sounds.
X Pull over and stop the vehicle safely, paying attention to road
and traffic conditions, and select a higher vehicle level.
Depending on the malfunction, it may be possible to raise the
vehicle.
X Visit a qualified specialist workshop. ¨or°
Malfunction The AIRMATIC function is restricted. The vehicle's handling
characteristics may be affected.
X
Do not drive faster than 50 mph (80km/h).
X Visit a qualified specialist workshop. ë
Off The HOLD function is deactivated. the vehicle is skidding.
A warning tone also sounds.
X
Reactivate the HOLD function later (Y page 196). 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 196). Radar Sensors
Deactivated See
Operator's Manual The radar sensor system is deactivated.
X
Switch on the radar sensor system (Y page 241).262
Display messages
On-board computer and displays
Page 267 of 420
Display messages Possible causes/consequences and
M SolutionsParking Guidance
Canceled Parking Guidance is deactivated. Possible causes are:
R
the vehicle is skidding.
R the sensors are dirty.
R a malfunction has occurred.
A warning tone also sounds.
X Reactivate Parking Guidance later ( Y page 205).
If the parking space symbol does not appear in the multifunction
display at speeds below 19 mph (30 km/h):
X Clean the sensors ( Y page 337).
X Restart the engine.
If the parking space symbol still does not appear in the
multifunction display at speeds below
19 mph (30 km/h):
X Visit a qualified specialist workshop. Parking Guidance has been deactivated because you are no longer
following the recommended path.
X
Park again and, while doing so, observe the display messages
in the multifunction display. Parking Guidance
Finished The vehicle is parked. A warning tone also sounds.
The display message disappears automatically.
DISTRONIC PLUS Off DISTRONIC PLUS has been deactivated (
Y page 185).
If it was deactivated automatically, a warning tone also sounds. DISTRONIC PLUS Now
Available DISTRONIC PLUS is operational again after having been
temporarily
unavailable. You can now reactivate DISTRONIC PLUS
(Y page 185). Display messages
265
On-board computer and displays Z
Page 268 of 420
Display messages Possible causes/consequences and
M SolutionsDISTRONIC PLUS
Currently
Unavailable See
Operator's Manual DISTRONIC PLUS is temporarily inoperative. Possible causes are:
R
function is impaired due to heavy rain or snow.
R the sensors in the radiator grill and the bumper are dirty.
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.
A warning tone also sounds.
When the causes stated above no longer apply, the display
message disappears.
DISTRONIC 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 175).
X Clean the sensors in the radiator grill and the bumper
(Y page 337).
X Restart the engine. DISTRONIC PLUS
Inoperative DISTRONIC PLUS is defective.
BAS PLUS (Brake Assist PLUS) and PRE-SAFE
®
Brake may be
inoperative as well.
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC PLUS
Passive You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Remove your foot from the accelerator pedal. DISTRONIC PLUS
- - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 185).266
Display messagesOn-board computer and displays
Page 269 of 420
Display messages Possible causes/consequences and
M SolutionsCruise Control
Inoperative Cruise control is defective.
A warning tone also sounds.
X
Visit a qualified specialist workshop. Cruise Control
- - - mph A condition for activating cruise control has not been fulfilled.
You have tried to store a speed below
20 mph (30 km/h), for
example.
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 183). Display messages
267
On-board computer and displays Z
