Page 681 of 801
680 Practical hintsWhat 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/consequence
Possible solution
Coolant Low
Stop Vehicle
Turn Engine Off
The 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 422).
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 682 of 801
681 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Coolant Low
Stop Vehicle
Turn Engine Off
The poly-V-belt could be broken.
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 422).
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 683 of 801
682 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Coolant Low
Stop Vehicle
Turn Engine Off
Restart 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 684 of 801
683 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Gas Cap Loose
A 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 570).
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.
Reserve Fuel
The fuel level has dropped below the re-
serve mark.
Refuel at the next gas station (
page 570).
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 422).
Close the hood (
page 574).
There is otherwise danger of an accident.
Page 685 of 801
684 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Key Not
Detected
The 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 422).
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 422).
Remove KEYLESS-GO* button from the
starter switch (
page 371).
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 371).
Page 686 of 801
685 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Close Doors
to Lock Vehicle
You wanted to lock the vehicle but not all
doors were closed.
Close doors and lock vehicle again.
Don’t Forget
Your Key
This 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.
Take Your Key
From Ignition
You have forgotten to remove the
SmartKey.
Remove the SmartKey from the starter
switch.
Replace
Key Battery
The batteries in the SmartKey with
KEYLESS-GO* are discharged.
Replace the batteries (
page 712).
Key Detected
In Vehicle
A 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 687 of 801
686 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Key Not
Detected
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 371).
Key Being
Initialized…
Please Wait
The SmartKey with KEYLESS-GO* is be-
ing initialized in the vehicle.
Wait until the message disappears from the
multifunction display.
Remove "START" Button
and Insert Key
The KEYLESS-GO* system is malfunc-
tioning.
Remove KEYLESS-GO* button from the
starter switch (
page 371).
Operate the vehicle with the SmartKey in the
starter switch.
Obtain
a New Key
The SmartKey with KEYLESS-GO* must
be replaced.
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Key Does Not
Belong to Vehicle
The SmartKey in the starter switch does
not belong to your vehicle.
Remove the SmartKey from the starter
switch.
Page 688 of 801
687 Practical hints
What to do if …?
Display
Possible cause/consequence
Possible solution
Check
Center Brake Lamp
The high mounted brake lamp is malfunc-
tioning. This message will only appear if a
critical number of light emitting diodes have
stopped working.
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Check Left
Cornering Light
The left-hand corner-illuminating lamp is
malfunctioning.
Replace the bulb as soon as possible
(page 714).
Check Right
Cornering Light
The right-hand corner-illuminating lamp is
malfunctioning.
Replace the bulb as soon as possible
(page 714).
Check
Left Low Beam
The left low beam lamp is malfunctioning.
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Check
Right Low Beam
The right low beam lamp is malfunctioning.
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Active Headlamps
Inoperative
The active headlamps are malfunctioning.
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
