Page 376 of 491

375 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
2
Brake wear
Visit workshop
The brake pads have reached their wear
limit.
Brake pad thickness must be visually
inspected at the intervals specified in
the Maintenance Booklet.
Have the brake pads replaced as soon
as possible.
T
Reduced braking power
Depress brake
pedal fully
The SBC brake system is in emergency
operation mode. Considerably greater
brake pedal force is required and the
stopping distance is increased.
The maximum speed is limited to 55 mph
(90 km / h).
Do not drive any further.
Stop the vehicle and notify an autho-
rized Mercedes-Benz Center.
Significantly greater force must be ap-
plied to the brake pedal.
Call for Roadside Assistance.
(USA only);(Canada only)3
Reduced braking power
Start engine
The battery has insufficient voltage and
cannot supply sufficient power to the
SBC brake system.
Start the engine.
The message disappears when suffi-
cient voltage is available.
!Brake pad thickness must be visually
inspected by a qualified technician at
the intervals specified in the
Maintenance Booklet.
Page 380 of 491

379 Practical hints
What to do if …
During severe operation conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.
Stop the vehicle.
Only start the engine again after the
message disappears. You could other-
wise damage the engine.
Warning!
G
Driving when your engine is badly overheat-
ed 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 and can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
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). Doing so may cause serious
damage which is not covered by the
Mercedes-Benz Limited Warranty.
Page 385 of 491

384 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
%
Hood open
You are driving with the hood open.
Close the hood (
page 299).
F
Key
Check battery
The SmartKey with KEYLESS-GO* batter-
ies are discharged.
Change the batteries (
page 408).
Key
not recognized
The SmartKey with KEYLESS-GO* is not
recognized while the engine is running
because
the SmartKey with KEYLESS-GO* is
not in the vehicle
there is strong radio-frequency inter-
ference
Stop the vehicle as soon as it is safe
to do so.
Search for the SmartKey.
Otherwise the vehicle cannot be cen-
trally locked nor can the engine be
started again after the engine is
stopped.
Key
not recognized
The SmartKey with KEYLESS-GO* is mo-
mentarily not recognized.
Change the position of the SmartKey
in the vehicle.
Operate the vehicle with the
SmartKey in the starter switch if nec-
essary.
Key
still in vehicle
A SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the
vehicle from the outside.
Take the SmartKey out of the vehicle.
Keyless Go
Check system
The KEYLESS-GO* system is malfunction-
ing.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Page 405 of 491
404 Practical hintsUnlocking / locking in an emergencyUnlocking the vehicle
If you are unable to unlock the vehicle with
the SmartKey, open the driver’s door using
the mechanical key.
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in the direction of
the arrow and slide mechanical key2
out of the housing.Unlocking the driver’s door
3Unlocking
4Locking
Unlock the door with the mechanical
key. To do so, push the mechanical key
in the lock until it stops and turn it to
the left.
iUnlocking driver’s door and/or the
trunk with the mechanical key will trig-
ger the anti-theft alarm system. To can-
cel the alarm, insert the SmartKey or
SmartKey with KEYLESS-GO* in the
starter switch.
Page 419 of 491

418 Practical hintsFlat tireIn the case of a flat tire, you may tempo-
rarily use the spare wheel when observing
the following restrictions:
Do not exceed a vehicle speed of
50 mph (80 km / h).
Drive to the nearest tire repair facility
to have the flat tire repaired or re-
placed as appropriate.
Do not operate vehicle with more than
one spare wheel mounted.
Preparing the vehicle
Park the vehicle as far as possible from
moving traffic on a hard surface.
Turn on the hazard warning flashers.
Engage the steering wheel lock in the
straight-ahead position and set the
parking brake.
Move the selector lever toP.
Vehicles with SmartKey:
Turn off the engine (
page 57).
Remove the SmartKey from the starter
switch.Vehicles with SmartKey with
KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* start/stop button on the
gear selector lever once (
page 59).
Open the driver’s door (this puts the ig-
nition in position0, same as with the
SmartKey removed from the starter
switch). The driver’s door then can be
closed again.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Warning!
G
The dimensions of the Minispare wheel and
the collapsible tire are different from those
of the road wheels. As a result, the vehicle
handling characteristics change when driv-
ing with a spare wheel mounted.
The spare wheel should only be used tempo-
rarily, and replaced with a regular road
wheel as quickly as possible.
iOpen door only when conditions are
safe to do so.
Page 426 of 491

425 Practical hints
Batteries
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 305).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for main-
tenance intervals or contact an autho-
rized Mercedes-Benz Center for further
information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. The same applies if
battery is disconnected. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes may only be applied to
the front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, refer to “SBC brake
system” (
page 92).
Page 427 of 491

426 Practical hintsBatteriesDisconnecting the battery
Depress parking brake firmly or move
gear selector lever to positionP.
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Press the start / stop button until
the engine shuts off.
Open the driver’s door.
Open the tailgate.
Read and observe safety instructions
and precautions (
page 425).
Access the cargo compartment under-
neath the third row seat cushions and
footwell (
page 401).
Remove cover to access battery
(page 424).
Disconnect battery negative lead1.
Remove cover2 from the positive ter-
minal.
Disconnect the battery positive lead.
Removing the battery
Remove the screw-nuts securing the
battery.
Remove the battery bracket.
Take out the battery.
Warning!
G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button on the gear selector lever will
have no effect
the gear selector lever will remain
locked in positionP
Page 432 of 491

431 Practical hints
Towing the vehicle
!
To be certain to avoid a possibility of
damage to the drive train, however, we
recommend the drive shaft be discon-
nected at the rear axle drive flange (ve-
hicles with 4MATIC: disconnected at
the front and rear axle drive flanges) for
any towing beyond a short tow to a
nearby garage.
Warning!
G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:
the engine will not run
there is a malfunction in the SBC brake
system
there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
as that will be necessary to adequately con-
trol the towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey is in
starter switch position2.
If the SmartKey is left in the starter switch
position0 for an extended period of time, it
can no longer be turned in the switch. In this
case, the steering is locked. To unlock, re-
move SmartKey from starter switch and re-
insert.
Warning!
G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes may only be applied to
the front wheels. Stopping distance is in-
creased! Adapt your driving style according-
ly. For more information, refer to “SBC brake
system” (
page 92).
With the engine not running, there is no
power assistance for the steering system. In
this case, it is important to keep in mind that
a considerably higher degree of effort is nec-
essary to steer the vehicle. Adapt your driv-
ing accordingly.