
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

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

Tires
Display messages Possible causes/consequences and
M SolutionsCheck
Tire Pressure 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
following 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 175).
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressures and, if necessary, correct the tire
pressure.
X Restart the tire pressure loss warning system when the tire
pressure is correct (Y page 370). Check Tire Pressure
Then Restart Run
Flat Indicator The tire pressure loss warning system generated a display
message 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 370).Run Flat Indicator
Inoperative The tire pressure loss warning system is faulty.
X
Visit a qualified specialist workshop. Tire pressure
will be displayed
after driving a
few minutes The tire pressure monitor is measuring the tire pressure.
X
Drive on.
The
tire pressures appear in the multifunction display after you
have been driving for a few minutes. Tire Press. Monitor
Inoperative The tire pressure monitor is faulty.
X
Visit a qualified specialist workshop.268
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsTire Pressure
Monitor
Inoperative No
Wheel Sensors The wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.
X
Mount wheels with suitable tire pressure sensors.
The
tire pressure monitor is activated automatically after driving
for a few minutes. Check
Tire Press. The tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.
G WARNING
With tire pressures which are too low, there is a risk of the
following 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 175).
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressure (Y page 370).
X If necessary, correct the tire pressure. Warning
Tire Malfunction The tire pressure in one or more tires has dropped suddenly. The
wheel position is shown in the multifunction display.
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 175).
X If there is a flat tire, inspect the tires ( Y page 344). Display messages
269
On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutionsh
Tire Press. Check
Tire Pressure The tire pressure in one or more tires has dropped significantly.
G WARNING
With tire pressures which are too low, there is a risk of the
following 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 175).
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressure (Y page 370).
X If necessary, correct the tire pressure. h
Correct 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 370).
X If necessary, correct the tire pressure. Vehicle
Display messages Possible causes/consequences and
M SolutionsShift to 'P' or 'N'
to Start Engine You have attempted to start the engine with the transmission in
position R or D.
X
Shift the transmission to position P or N.Auxiliary Battery
Malfunction The auxiliary battery for the automatic transmission is no longer
being charged.
X
Visit a qualified specialist workshop. Apply Brake to
Shift
from 'P' You have attempted to move the transmission selector lever to
position D, R or N without depressing the brake pedal.
X
Depress the brake pedal. Display messages
271
On-board computer and displays Z

Problem Possible causes/consequences and
M SolutionsX
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 331).
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 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. Driving systems
Problem Possible causes/consequences and
M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion.
A warning tone
also sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X
Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on DISTRONIC PLUS ( Y page 185).
Further information on PRE-SAFE ®
Brake (Y page 72). Indicator and warning lamps in the instrument cluster
285
On-board computer and displays Z

Tires
Problem Possible causes/consequences and
M Solutionsh
USA only:
The
yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit. The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
G WARNING
With tire pressures which are too low, there is a risk of the
following 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 175).
X Observe the additional display messages in the multifunction
display.
X If there is a flat tire, inspect the tires ( Y page 344).
X Check the tire pressure (Y page 370).
X If necessary, correct the tire pressure. h
USA only:
The
yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit. The tire pressure monitor is faulty.
G WARNING
The system is possibly unable to recognize or register low tire
pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Visit a qualified specialist workshop.286
Indicator and warning lamps in the instrument cluster
On-board computer and displays

X
Fold down sun visor :.
X Pull sun visor : out of retainer =.
X Swing sun visor : to the side.
X Vehicles with an additional sun visor:
slide sun visor : horizontally as desired.
X Fold down additional sun visor ; to the
windshield. Roller sunblinds on the rear side
windows
! Always
guide the roller sunblind by hand.
Do not let it snap back suddenly as this
would damage the automatic roller
mechanism.
! Do not drive the vehicle with the roller
sunblind hooked in and the side windows
opened simultaneously. The roller sunblind
can jump out of the retainers and spring
back suddenly when driving at high speeds,
e.g. when driving on the freeway. This could
damage the inertia reel. Therefore, either
close the side window or retract the roller
sunblind before driving at high speeds. X
To extend: pull the roller sunblind out by
tab :
and hook it onto retainers ; at the
top of the window. Rear window roller sunblind (Sedan)
Important safety notes G
WARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unattended in the
vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. A child's unsupervised
access
to a vehicle could result in an accident
and/or serious personal injury. The children
could:
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts. G
WARNING
When adjusting a roller sunblind, the roller
blind moves up or down. You might become
trapped in the process.
In
the event of danger, briefly press the button
for the roller sunblind to change the roller
blind's direction of movement.
Extending/retracting the roller
sunblind !
Make sure that the roller sunblind can
move freely. Otherwise, the roller sunblind
or other objects could be damaged. Features
307
Stowage and features Z