Page 613 of 723

610 Practical hints
What to do if …?
During severe operating conditions,
e.g. stop-and-go traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display Possible cause/consequencePossible solution
Coolant level
Stop vehicle!
Switch engine offThe coolant is too hot. Stop the vehicle in a safe location or as soon
as it is safe to do so and immediately turn off
the engine.
Only start the engine again after the message
disappears. You could otherwise damage the
engine.
Observe the coolant temperature gauge in
the instrument cluster (
page 30).
Warning!G
Driving when your engine is overheated
can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously
burned.
Steam from an overheated engine can
cause serious burns which can occur
just by opening the engine hood. Stay
away from the engine if you see or hear
steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of
the vehicle and do not stand near the vehicle
until the engine has cooled down.!The engine should not be operated with the
coolant temperature above 248°F (120°C). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.
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Page 615 of 723
612 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Coolant level
Stop vehicle!
Switch engine offRestart the engine.
If this message disappears from the multi-
function display:
Drive immediately to the nearest autho-
rized Mercedes-Benz Center.
If this message does not disappear from the
multifunction display:
Call Roadside Assistance.
The cooling fan for the coolant is malfunc-
tioning.Observe the coolant temperature gauge in
the instrument cluster (
page 30).
Have the fan replaced as soon as possible.
You are driving with one or both doors
open.
The display symbol shows you which doors
are open.Close the doors.
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Page 617 of 723

614 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Key
not recognizedThe SmartKey with KEYLESS-GO* is not
recognized while the engine is running be-
cause the SmartKey with KEYLESS-GO* is
not in the vehicle.Stop the vehicle in a safe location or as soon
as it is safe to do.
Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again
after the engine is stopped.
The SmartKey with KEYLESS-GO* is not
recognized while the engine is running be-
cause there is strong radio-frequency inter-
ference.Stop the vehicle in a safe location or as soon
as it is safe to do.
Remove KEYLESS-GO* button from over
starter switch (
page 337).
Operate the vehicle with the SmartKey in the
starter switch.
The SmartKey with KEYLESS-GO* is mo-
mentarily not recognized.Change the position of the SmartKey in the
vehicle.
If necessary, operate vehicle using SmartKey
with KEYLESS-GO* in starter switch under
KEYLESS-GO* button (
page 337).
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Page 634 of 723

631 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Shift to 'P'You have attempted to turn off the engine
with the KEYLESS-GO* start/stop button
and opened the driver’s door with the auto-
matic transmission not shift to positionP.Shift the automatic transmission toP
(
page 389).
or
Close the driver’s door.
You are driving with the trunk open.Close the trunk (page 462).
Washer fluid,
please refillThe water level has dropped to approx.
1.1 US qts (1.0 l).Add washer fluid (page 519).
Seat backrest,
Front Left
not lockedThe driver seat backrest is not engaged.
The driver’s seat belt can not secure the
driverFold back and push the seat backrest until
the seat cushion and seat backrest audibly
engage into the driving position.
Seat backrest,
Front Right
not lockedThe passenger seat backrest is not en-
gaged.
The front passenger’s seat belt can not se-
cure the passengerFold back and push the seat backrest until
the seat cushion and seat backrest audibly
engage into the driving position.
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Page 638 of 723

635 Practical hints
Unlocking/locking in an emergency
Unlocking/locking in an emergency
Unlocking the vehicle
If you are cannot unlock the vehicle with
the SmartKey or KEYLESS-GO*, unlock the
driver’s door and the trunk using the me-
chanical key. Removing the mechanical key
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in the direction of
arrow.
Slide mechanical key2 out of the
housing.Unlocking the driver’s door
Insert mechanical key2 into the driv-
er’s door lock until it stops.
Turn mechanical key2 counterclock-
wise to position1 and hold it there.
Pull the door handle until the locking
knob moves up.
The driver’s door is unlocked.
Pull the door handle once more to open
the driver’s door.
iUnlocking the vehicle with the mechanical
key and opening the driver’s door or the trunk
with the mechanical key will trigger the anti-theft
alarm system (
page 77).
To cancel the alarm, insert the SmartKey or
SmartKey with KEYLESS-GO* in the starter
switch.
1Unlocking
2Mechanical key
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Page 651 of 723

648 Practical hints
Replacing wiper blades
Vehicles with KEYLESS-GO*
Make sure the vehicle’s on-board elec-
tronics have status 1 (
page 337).
Turn combination switch to wiper
settingu (
page 372).
Press KEYLESS-GO start/stop button
repeatedly until windshield wipers
start.
Press KEYLESS-GO start/stop button
when the wiper arms are in a vertical
position.
Removing wiper blades
Fold the wiper arm forward until it
snaps into place.
Turn the wiper blade at a right angle to
wiper arm (arrow 1).
Slide the wiper blade sideways out of
the retainer in the direction of
arrow2.
Installing wiper blades
Slide the wiper blade onto wiper arm
until it locks in place.
Rotate the wiper blade into position
parallel to wiper arm.
Fold the wiper arm backward to rest on
the windshield. Make sure you hold
onto the wiper when folding the wiper
arm back.
!Do not pull on the wiper blade inserts. They
could tear.
!Make certain that the wiper blades are prop-
erly installed. Improperly installed wiper blades
may cause windshield damage.
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Page 667 of 723

664 Practical hints
Towing the vehicle
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the
vehicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels on
the ground or with the front axle raised, the start-
er battery must be connected and charged. Oth-
erwise:
you will not be able to switch on the ignition
you will not be able to engage the automatic
transmission in positionN (
page 394)
you cannot release the electronic parking
brake
For information on charging the starter battery
see “Batteries” (
page 655) or see “Jump start-
ing” (
page 660).
!Make sure that the electronic parking brake
is released. If the electronic parking brake is
malfunctioning, release it mechanically
(
page 637).
!If the vehicle is towed with the front axle
raised, the automatic transmission must be in
positionN and the engine must be shut off
(SmartKey or SmartKey with KEYLESS-GO* in
starter switch position0 or1). Active braking
action through the ESP
® may otherwise
seriously damage the brake system.
!When towing the vehicle with all wheels on
the ground, the automatic transmission must be
shifted to positionN and the SmartKey or
SmartKey with KEYLESS-GO* must be in starter
switch position2.
When towing the vehicle with all wheels on the
ground or the front axle raised, the vehicle may
be towed only for distances up to 30 miles
(50 km) and at a speed not to exceed 30 mph
(50 km/h).
!If the vehicle is towed with all wheels on the
ground or with the front axle raised, the trans-
mission must be in positionN.
If you turn off the engine using
the SmartKey and
remove the SmartKey from the starter
switch
or
open a door
the KEYLESS-GO* start/stop button and
open a door
the transmission will shift to park position P
automatically.
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Page 668 of 723

665 Practical hints
Towing the vehicle
If you want the gear position to remain in
neutral position N, observe the following
instructions.
Vehicles with SmartKey:
With the vehicle at a standstill and the
ignition switched on shift the
automatic transmission to neutral
positionN.
If engaged, manually release the elec-
tronic parking brake (
page 385).
Switch off the ignition and leave the
SmartKey in the starter switch.Vehicles with KEYLESS-GO*:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
With the ignition switched on shift the
automatic transmission to park
positionP.
Release the brake pedal.
Remove the KEYLESS-GO start/stop
button from the starter switch
(
page 337).
Insert the SmartKey with KEYLESS-GO
into the starter switch.
Switch on the ignition.
Depress the brake pedal.
Shift the automatic transmission to
neutral positionN.
Release the brake pedal.
If engaged, manually release the
electronic parking brake (
page 385).
Switch off the ignition and leave the
SmartKey with KEYLESS-GO in the
starter switch.
Warning!G
When leaving the SmartKey or SmartKey
with KEYLESS-GO* in the starter switch, do
not leave children unattended in the vehicle.
It is possible for children to switch on the
ignition which could result in unsupervised
use of vehicle equipment. Unsupervised use
of vehicle equipment could result in an
accident and/or serious personal injury.
iWhen towing the vehicle with all wheels on
the ground, please note the following:
With the automatic central locking activated and
the SmartKey or SmartKey with KEYLESS-GO* in
starter switch position 2, the vehicle doors lock
if the left front wheel as well as the right rear
wheel are turning at vehicle speeds of approxi-
mately 9mph (15km/h) or more.
To prevent the vehicle doors from locking,
deactivate the automatic central locking
(
page 334).
iTo signal turns while being towed with the
hazard warning flasher in use, turn SmartKey or
SmartKey with KEYLESS-GO* in starter switch to
position2 and activate the combination switch
for the left or right turn signal in the usual
manner – only the selected turn signal will
operate.
Upon canceling the turn signal, the hazard
warning flasher will operate again.
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