
Problem Possible causes/consequences and
M Solutions֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, the HOLD function, hill start assist and ESP ®
trailer
stabilization are temporarily unavailable.
BAS and the adaptive brake lights may also have failed.
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
movements 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. å
The yellow ESP
®
OFF
warning
lamp is lit while
the engine is running. You have engaged the differential locks. ABS, ESP
®
, 4ETS and BAS
have been deactivated.
X Disengage the differential locks.
ESP ®
, 4ETS and BAS are subsequently reactivated.
X Observe the additional display messages in the multifunction
display.254
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine
Problem Possible causes/consequences and
M Solutions;
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 running 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
specialist
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
running.
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
workshop. ?
The red coolant
warning lamp lights up
while the engine is
running
and the coolant
temperature 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 Apply the parking brake.
X Consult a qualified specialist workshop.256
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Problem Possible causes/consequences and
M SolutionsX
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 156).
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 291).
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 below 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-start driving. Driving systems
Problem Possible causes/consequences and
M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion.
The distance to the vehicle in front is too small for the speed
selected.
X
Increase the distance. ·
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 177).258
Warning and indicator lamps in the instrument cluster
On-board computer and displays

when not in use. Otherwise, you could suffer
an electric shock and be seriously or even
fatally injured.
G
WARNING
Any device that you connect must have a
suitable plug and meet U.S. standards. Never
pull at a cable to disconnect a plug from a
115 V AC power socket. Never use a damaged
connection cable. The 115 V AC power socket
must never be connected to another 115 V
AC power source. Do not use a converter with
an earthed plug for the 115 V AC power
socket. This could cause serious injury to you
and/or other people. G
WARNING
If the 115 V AC power socket is damaged or
pulled
out of the trim, do not use or touch the
115 V AC power socket. The use of a 115 V
AC power socket that has been damaged or
pulled out of the trim could cause serious
injury to you or others. 115 V power socket
: provides an AC
voltage of 115 V so that small electronic
devices can be connected. These devices,
such as games consoles, chargers and
laptops, should not consume more than a
maximum of 150 W altogether. Requirements for operation of these devices:
R
the 12 V sockets in the rear compartment
and the cargo compartment are
operational ( Y page 271).
R the
plug of the electronic device is plugged
into 115 V power socket :.
R the on-board power supply is within a
permissible voltage range.
R the electronic device's maximum power
output does not exceed 150 W.
X Open flap =.
X Switch on the ignition.
X Insert the plug of the electronic device into
115 V power socket :.
Indicator lamp ; lights up.
If indicator lamp ; does not light up,
please read the section on malfunctions.
X To turn off: disconnect the plug from
115 V power socket :.
Ensure that you do not pull on the cord.
X Close flap =.
Possible causes of malfunctions:
R the on-board power supply is not within a
permissible voltage range.
R the
temperature of the DC/AC converter is
temporarily too high.
R some small electronic devices have a
constant nominal power of less than
150 W, but a very high switch-on current.
In that case, there is a possibility that these
devices will not function properly as 115 V
socket : is not able to provide a high
enough current.
X If indicator lamp ; still does not light up,
contact a qualified specialist workshop. mbrace
Important safety notes !
You must have a license agreement to
activate the mbrace service. Ensure that
your
system is activated and ready for use,272
Features
Stowage and features

door opener. Before performing these
steps, make sure that new batteries have
been inserted in the garage door remote
control.
R Align
the antenna cable of the garage door
opener unit. This can improve signal
reception/transmission.
Opening/closing the garage door :
Indicator lamp
;=? Transmitter buttons
A Garage door remote control
B Transmitter button on the garage
door remote control
Once programmed, the integrated remote
control
will assume the function of the garage
door system's remote control. Please also
read the operating instructions for the garage
door system.
X Turn the SmartKey to position
2(Y page 139) in the ignition lock.
X Press transmitter button ;, = or ? on
the integrated remote control in the rear-
view
mirror that is programmed to operate
the garage door.
Garage door system with fixed code:
indicator lamp : lights up continuously.
Garage door system with rolling code:
indicator lamp : flashes briefly and then
lights up for approximately two seconds.
This is repeated for up to 20 seconds.
i The transmitter will transmit a signal for
as long as the transmitter button is being
pressed. The transmission will be halted after a maximum of 20 seconds and
indicator lamp
: will flash. Press the
transmitter button again, if necessary.
Clearing the remote control memory :
Indicator lamp
;=? Transmitter buttons
A Garage door remote control
B Transmitter button on the garage
door remote control
X Turn the SmartKey to position
2(Y page 139) in the ignition lock.
X Press and hold transmitter buttons ;
and ? for approximately
20 seconds until
indicator lamp : flashes rapidly.
The memory is cleared.
i You should clear the remote control
memory before selling the vehicle. Floormat on the driver's side
G
WARNING
Whenever you are using a floormat, make sure
there is enough clearance and that the
floormat is securely fastened.
The floormat should always be securely
fastened using the fastening equipment.
Before driving off, check that the floormat is
securely
in place and adjust it if necessary. A
loose floormat could slip and hinder proper
functioning of the pedals.
Do not place several floormats on top of each
other as this may impair pedal movement. 284
Features
Stowage and features

malfunction indicator is combined with the
low tire pressure telltale. When the system
detects a malfunction, the warning lamp will
flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the
vehicle is started as long as the malfunction
exists.
When
the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS
malfunctions may occur for a variety of
reasons, including the installation of
incompatible replacement or alternate tires
or wheels on the vehicle that prevent the
TPMS from functioning properly. Always
check the TPMS malfunction telltale after
replacing one or more tires or wheels on your
vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS to
continue to function properly.
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure suitable for the operating situation
(Y page 322). Note that the correct tire
pressure for the current operating situation
must first be taught-in to the tire pressure
monitor. If there is a substantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in. Restart the tire pressure
monitor after adjusting to the cold tire
pressure ( Y page 327). The current
pressures are saved as new reference values.
As a result, a warning message will appear if
the tire pressure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
(Y page 322).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tire is penetrated by a foreign object. In the
event of a sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering maneuvers. If a tire pressure monitor system is installed,
the vehicle's wheels have sensors installed
that
monitor the tire pressures in all four tires.
The tire pressure monitor warns you if the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct wheel electronics units are installed
on each wheel.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss/malfunctions (USA)
or pressure loss (Canada). Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitor is malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R USA only: if the warning lamp flashes for
around a minute and then remains lit
constantly, the tire pressure monitor is
malfunctioning.
Information on tire pressures is displayed in
the multifunction display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the multifunction display.
USA only: if there is a malfunction with the
tire pressure monitor it can take more than
ten minutes until the malfunction is shown by
the tire pressure warning lamp flashing for
approximately one minute and then lighting
up continuously. When the malfunction has
been rectified, the tire pressure warning lamp
goes out after a few minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those
measured at a gas station with a pressure
gauge. The tire pressures shown by the on-
board computer refer to those measured at
sea level. At high altitudes, the tire pressure
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the tire
pressures. 326
Tire pressure
Wheels and tires

The operation of the tire pressure monitor can
be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
i
USA only:
This device complies with part
15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
i Canada only:
This device complies with RSS-210 of
Industry Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
Checking tire pressure electronically X
Make sure that the SmartKey is in
position 2 (Y
page 139) in the ignition lock.
X Press the = or ; button on the
steering wheel to select the Serv. menu.
X Press the 9 or : button to select
Tire Pressure.
X Press button a.
The
current tire pressure for each wheel will
be displayed in the multifunction display.
If the vehicle has been parked for over
20 minutes, the message Tire pressure will be displayed after driving a
few minutes appears.
After a teach-in period, the tire pressure
monitor
automatically recognizes new wheels
or new sensors. As long as a clear allocation
of the tire pressure values to the individual
wheels is not possible, the Tire Pressure
Monitor Active display message is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
i If a spare wheel is mounted, the system
may continue to show the tire pressure of
the wheel that has been removed for a few
minutes. If this occurs, note that the value
displayed for the position where the spare
wheel is mounted is not the same as the
spare wheel's current tire pressure.
Tire pressure monitor warning
messages If the tire pressure monitor detects a
significant
pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
Each tire that is affected by a significant loss
of pressure is highlighted in the pressure
display.
X If the Correct Tire PressureCorrect
Tire Pressure message appears in the
multifunction display, check the tire
pressure
on all four wheels and correct it if
necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correct positions.
Restarting the tire pressure monitor When you restart the tire pressure monitor,
all
existing warning messages are deleted and
the warning lamps go out. The monitor uses Tire pressure
327
Wheels and tires Z