Page 646 of 761
645 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Coolant,
please refill
See Oper. ManualThe coolant level is too low.Add coolant (page 547).
If you have to add coolant frequently, have
the cooling system checked by an authorized
Mercedes-Benz Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz Lim-
ited Warranty.
Do not drive without a sufficient amount of cool-
ant in the cooling system. The engine will over-
heat, causing major engine damage.
Page 647 of 761

646 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.
Engage the electronic parking brake
(
page 395).
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 28).
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.
Page 648 of 761
647 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Coolant level
Stop vehicle!
Switch engine offThe poly-V-belt could be broken.Stop the vehicle in a safe location or as soon
a s it is sa fe t o do so and im media tely turn off
the engine.
Engage the electronic parking brake
(
page 395).
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative water
pump which may result in damage to the en-
gine.
Notify an authorized Mercedes-Benz Center.
If it is intact:
Do not continue to drive the vehicle with this
message displayed. Doing so could result in
serious engine damage that is not covered by
the Mercedes-Benz Limited Warranty.
Observe the coolant temperature gauge in
the instrument cluster (
page 28).
(Continued on next page)
Page 649 of 761
648 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 28).
Have the fan replaced as soon as possible.
You are driving with one or more doors
open.
The display symbol shows you which doors
are open.Close the doors.
Page 650 of 761
649 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Gas cap openA loss of pressure has been detected in the
fuel system. The fuel cap may not be closed
properly or the fuel system may be leaky.Check the fuel cap (page 538).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an autho-
rized Mercedes-Benz Center.
You are driving with the hood open.Stop your vehicle as soon as it is safe to do
so.
Engage the electronic parking brake
(
page 395).
Close the hood (page 542).
There is otherwise danger of an accident.
Page 651 of 761

650 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.
Engage the electronic parking brake
(
page 395).
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.
Engage the electronic parking brake
(
page 395).
Remove KEYLESS-GO* button from the
starter switch (
page 345).
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 345).
Page 652 of 761
651 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Close doors
to lock themYou wanted to lock the vehicle but not all
doors were closed.Close doors and lock vehicle again.
Do not
forget keyThis display appears (for a maximum of
60 seconds) if the driver’s door is opened
with the engine turned off and no SmartKey
in the starter switch.
This message is only a reminder.Take the SmartKey or SmartKey with
KEYLESS-GO* with you when leaving the ve-
hicle.
Please
remove keyYou have forgotten to remove the
SmartKey.Remove the SmartKey from the starter
switch.
Change
key batteriesThe batteries in the SmartKey with
KEYLESS-GO* are discharged.Replace the batteries (page 676).
Key
still in vehicleA SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the ve-
hicle from the outside.Take the SmartKey with KEYLESS-GO* out of
the vehicle.
Page 653 of 761
652 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Key
not recognizedThe 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 345).
Key being
initialized…
Please waitThe SmartKey with KEYLESS-GO* is being
initialized in the vehicle.Wait until the message disappears from the
multifunction display.
Remove starting
button, then
insert keyThe KEYLESS-GO* system is malfunction-
ing.Remove KEYLESS-GO* button from the
starter switch (
page 345).
Operate the vehicle with the SmartKey in the
starter switch.
Replace keyThe SmartKey with KEYLESS-GO* must be
replaced.Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.