
Display messages
Possible causes/consequences and
0050
0050Solutions DISTRONIC
DISTRONIC
PLUS
PLUSCur‐
Cur‐
rently
rently Unavailable
Unavailable
See
See Operator's
Operator's Man‐
Man‐
ual
ual DISTRONIC PLUS is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator trim 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 sta-
tions 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 mes-
sage disappears.
DISTRONIC PLUS 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 161).
X Clean the sensors in the radiator trim and the bumper
(Y page 287).
X Restart the engine. DISTRONIC PLUS DISTRONIC PLUS
Inoperative 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 DISTRONIC
PLUS
PLUSSus‐
Sus‐
pended
pended 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 171). 234
Display
messagesOn-board computer and displays 

Tires
Display messages
Possible causes/consequences and
0050
0050Solutions Check
Check
Tire Pressure Soon Tire Pressure Soon Canada only:
The tire pressure loss warning system has detected a significant
loss in pressure.
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 161).
X Check the tires and, if necessary, follow the instructions for a
flat tire (Y page 292).
X Check the tire pressures and, if necessary, correct the tire pres-
sure.
X Restart the tire pressure loss warning system when the tire
pressure is correct (Y page 318).Check Check
Tire
TirePressure
Pressure
Then Restart Run
Then Restart Run
Flat Indicator Flat Indicator Canada only:
The tire pressure loss warning system generated a display mes-
sage and has not been restarted since.
X Set the correct tire pressure in all four tires.
X Restart the tire pressure loss warning system (Y page 318).Run Flat Indicator Run Flat Indicator
Inoperative Inoperative Canada only:
The tire pressure loss warning system is faulty.
X Visit a qualified specialist workshop. Please Correct Please Correct
Tire Pressure Tire Pressure 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 318).
X If necessary, correct the tire pressure.
X Restart the tire pressure monitor (Y page 321).236
Display
messagesOn-board computer and displays 

Display messages
Possible causes/consequences and
0050
0050Solutions Risk of Rolling
Risk of Rolling
Transmission Not Transmission Not
in P in P
G
WARNING
You have switched off the engine with the Start/Stop button and
opened the driver's door.
You wanted to lock the vehicle.
A warning tone also sounds.
or
You have turned off the engine with the Start/Stop button and
opened the driver's door while the transmission was in position N.
X Shift the transmission to position P. While the HOLD function or DISTRONIC PLUS is active, you have:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the hood
A tone may also sound at regular intervals. If you attempt to lock the vehicle, the tone becomes louder.
You cannot start the engine.
X Shift the transmission to position P.
You can restart the engine. Service Required Service Required
Do Do
Not
Not Shift
Shift Gears
Gears
Visit Dealer
Visit Dealer You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position Dis selected:
X Drive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R,Nor Pis selected:
X Notify a qualified specialist workshop or breakdown service. Display
messages
239On-board computer and displays Z 

Display messages
Possible causes/consequences and
0050
0050Solutions 00CC
Power Power
Steering
Steering Mal‐
Mal‐
function See Oper‐
function See Oper‐
ator's Manual ator's Manual The power steering is malfunctioning.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. 0058
Trunk Partition Trunk Partition
Open Open The trunk partition is open.
X Close the trunk partition (Y page 90).Phone No Service
Phone No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X Wait until the mobile phone operational readiness symbol
appears in the multifunction display. 0059
Decrease Speed Decrease Speed You wanted to open the roof while the vehicle was in motion.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Open the roof (Y page 88). 0059
Vario-Roof Lower‐ Vario-Roof Lower‐
ing ing The roof is not fully opened or closed. The hydraulics are depres-
surized.
X Fully open or close the roof (Y page 88).0059
Open/Close Vario- Open/Close Vario-
Roof Completely Roof Completely The roof is not locked.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Push or pull the roof switch until the roof is fully open or closed
(Y page 88). 0059
Start Engine See Start Engine See
Operator's Manual Operator's Manual The on-board voltage is too low.
X Start the engine.
X After approximately ten seconds, repeat the opening or closing
procedure (Y page 88). Display
messages
241On-board computer and displays Z 

Display messages
Possible causes/consequences and
0050
0050Solutions 00AF
Don't Forget Your Don't Forget Your
Key Key The display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.
X Remember to take the KEYLESS-GO key with you when you
leave the vehicle. 00AF
Key Not Detected Key Not Detected
(red display message) The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
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 161).
X Locate the KEYLESS-GO key. 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 161).
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 The KEYLESS-GO key can continuously not be detected.
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. Display
messages
243On-board computer and displays Z 

Safety systems
Problem
Possible causes/consequences and
0050
0050Solutions 0027
(USA only)
004D (Canada only)
The red brake system
warning lamp comes on while the engine is run-
ning. A warning tone
also sounds. There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect 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 Secure the vehicle against rolling away (Y page 161).
X Do not add brake fluid. Adding more will not remedy the mal-
function.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. 0025
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Braking System) is deactivated due to a malfunc-
tion. BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic Stability
Program), PRE‑ SAFE®
, PRE‑SAFE ®
Brake, the HOLD function and
hill start assist are therefore also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The 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 an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. Warning and indicator lamps
245On-board computer and displays Z 

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
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 depends on the locally applicable legal require-
ments. If in doubt, check whether such legal regulations apply in the state in which you are currently driving. 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. 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 gauge is
defective.
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 161).
X Consult a qualified specialist workshop. Warning and indicator lamps
251On-board computer and displays Z 

Problem
Possible causes/consequences and
0050
0050Solutions 00AC
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
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 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 Secure the vehicle against rolling away (Y page 161).
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 281).
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-and-go traffic. 00AC
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.
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 Secure the vehicle against rolling away (Y page 161).252
Warning and indicator lampsOn-board computer and displays