Display messages
Possible causes/consequences and
M
MSolutions b
Check Check
Left
LeftDaytime
Daytime
Running
Running
Lamp Lampor Check Right
Check Right
Daytime Running
Daytime Running
Lamp Lamp The left or right-hand daytime running lamp is defective.
X Visit a qualified specialist workshop. b
Malfunction. See Malfunction. See
Operator's Manual Operator's Manual The exterior lighting is defective.
X Visit a qualified specialist workshop. b
Auto Auto
Lamp
LampFunction
Function
Inoperative
Inoperative The light sensor is defective.
X Visit a qualified specialist workshop. b
Switch Off Lights 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.Engine
Display messages
Possible causes/consequences and
M MSolutions +
Check Coolant Check Coolant
Level. See Opera‐ Level. See Opera‐
tor's Manual tor's Manual The coolant level is too low.
X Add coolant, observing the warning notes before doing so
(Y page 278).
X Have the coolant system checked at a qualified specialist work-
shop if the coolant needs topping up more often than usual. ? The fan motor is faulty.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. Display
messages
221On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Too Hot Coolant Too Hot
Stop Vehicle Stop Vehicle
Switch Engine Off Switch 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 150).
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 below 248 ‡ (120 †). Other-
wise, 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 †). The poly-V-belt may have torn.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Check the poly-V-belt.
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 Wait until the display message disappears before restarting the
engine. Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop. 222
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Blind Spot Assist
Blind Spot Assist
currently unavail‐ currently unavail‐
able able
See See
Operator's
Operator's Man‐
Man‐
ual
ual Blind Spot Assist is temporarily inoperative. Possible causes are:
R you have established the electrical connection between the
trailer and your vehicle.
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 9indicator lamps also light up in the exterior mir-
rors.
X When towing a trailer, confirm the display message with a.
If you are driving without a trailer and 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 Apply the parking brake.
X Clean the sensors (Y page 284).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
Blind Spot Assist is operational again. Blind Spot Assist Blind Spot Assist
or
Inoperative Inoperative Blind Spot Assist is defective.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. DISTRONIC PLUS DISTRONIC PLUS
Off Off DISTRONIC PLUS has been deactivated (Y
page 169).
If it was deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
Now Available Now Available DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 169). Display
messages
227On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions DISTRONIC PLUS
DISTRONIC PLUS
Currently Unavail‐ Currently Unavail‐
able. See Opera‐ able. See Opera‐
tor's Manual tor's Manual DISTRONIC is deactivated and temporarily inoperative. Possible
causes are:
R the DISTRONIC PLUS cover in the radiator trim is dirty
R function is impaired due to heavy rain or snow.
R the sensors in the bumpers are dirty.
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.
R the system is outside the operating temperature range.
R the transfer case is in the LOW RANGEtransmission position.
R the vehicle is on an uphill or a downhill slope of more than
22‑25%
R the on-board voltage is too low.
A warning tone also sounds.
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 Apply the parking brake.
X Clean the DISTRONIC PLUS cover in the radiator trim and the
bumper (Y page 284).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
DISTRONIC PLUS is operational again. DISTRONIC PLUS DISTRONIC PLUS
Inoperative Inoperative DISTRONIC PLUS is defective.
BAS (Brake Assist) may also have failed.
A warning tone also sounds.
X Visit a qualified specialist workshop. DISTRONIC PLUS DISTRONIC PLUS
Passive 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
DISTRONIC PLUS
- - - mph - - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS
(Y page 169). DISTRONIC
DISTRONIC
PLUS
PLUSand
and
SPEEDTRONIC
SPEEDTRONIC
Inoperative Inoperative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X Visit a qualified specialist workshop. 228
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Correct Tire Pres‐
Correct Tire Pres‐
sure 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 pressures at the next opportunity (Y page 313).
X If necessary, correct the tire pressure.
X Restart the tire pressure monitor (Y page 315).TirePress. Sen‐
TirePress. Sen‐
sor(s) Missing sor(s) Missing There is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.
X Have the faulty tire pressure sensor replaced at a qualified spe-
cialist workshop. Tire Pressure Mon‐ Tire Pressure Mon‐
itor Currently itor Currently
Unavailable Unavailable Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.
X Drive on.
The tire pressure monitor restarts automatically as soon as the
problem has been solved. h
Tire Tire
Pressure
Pressure Warn‐
Warn‐
ing, Tire Malfunc‐
ing, Tire Malfunc‐
tion tion The tire pressure in one or more tires has dropped suddenly. The
wheel position is shown in the multifunction display.
A warning tone also sounds.
G WARNING
If you drive with a flat tire, there is a risk of the following hazards: R a flat tire affects the ability to steer or brake the vehicle.
R you could 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 as you do so.
X Secure the vehicle against rolling away (Y page 150).
X If there is a flat tire, inspect the tires (Y page 292). Display
messages
231On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions h
Check Check
Tire
TirePressure
Pressure The tire pressure in one or more tires has dropped significantly.
The wheel position is shown in the multifunction display.
A warning tone also sounds.
G WARNING
With tire pressures which are too low, there is a risk of the fol-
lowing hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they may wear excessively and/or unevenly, which may greatly
impair tire 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
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away (Y page 150).
X If there is a flat tire, inspect the tires (Y page 292).
X Check the tire pressure (Y page 313).
X If necessary, correct the tire pressure. h
Correct Tire Pres‐ Correct Tire Pres‐
sure 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 pressures at the next opportunity (Y page 313).
X If necessary, correct the tire pressure. Vehicle
Display messages
Possible causes/consequences and
M
MSolutions Shift
Shift
to
toP
Por
or N
Nto
to
Start Engine
Start Engine You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. Auxiliary Battery Auxiliary Battery
Malfunction Malfunction The auxiliary battery for the automatic transmission is no longer
being charged.
X Visit a qualified specialist workshop at the next opportunity.
X Until then, set the automatic transmission to position Pbefore
you switch off the engine.
X Before leaving the vehicle, apply the parking brake. 232
Display
messagesOn-board computer and displays
Engine
Problem
Possible causes/consequences and
M
MSolutions ;
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
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. 8
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. 8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the
;
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. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gage 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 Apply the parking brake.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
243On-board computer and displays Z
Problem
Possible causes/consequences and
M
MSolutions ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
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.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunc-
tioning.
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 Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Apply the parking brake.
X Leave 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 278).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
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 coolant temperature is
below 248 ‡(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow 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.
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. 244
Warning and indicator lamps in the instrument clusterOn-board computer and displays