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 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 695 of 801
694 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Night View Assist
Lights ON or AUTO,
Not in R Gear
You have tried to switch on Night View As-
sist* but the light switch is not set to *
or B.
In addition, the automatic transmission is in
reverse gearR.
Turn the exterior lamp switch to * or
B (
page 399).
Shift the automatic transmission to park
positionP, neutral positionN or drive
positionD (
page 426).
Night View Assist
Only When
It Is Dark
You have tried to switch on Night View As-
sist* by daylight.
You can only switch on Night View Assist* when
it is dark.
Engine Oil Level Low
Stop Vehicle
Turn Engine Off
S 600 and S 65 AMG only:
There is no oil in the engine. There is a dan-
ger of engine damage.
Carefully bring the vehicle to a halt as soon
as it is safe to do so in a safe location.
Engage the electronic parking brake
(page 422).
Turn off the engine.
Add engine oil (
page 578) and check the
engine oil level (page 575).
Page 696 of 801

695 Practical hints
What to do if …?
When the message “Check Engine Oil Level
at Next Refueling” (all models except S 600
and S 65 AMG) or “Check Engine Oil Level
(Add 1 quart). (Canada:1Liter)” (S 600
and S 65 AMG) appears while the engine is
running and at operating temperature, the
engine oil level has dropped to approxi-
mately the minimum level.When this occurs, the warning is at first in-
termittent and then remains on if the oil
level drops further.
Visually check for oil leaks. If there are no
obvious oil leaks, drive to the nearest ser-
vice station to refill engine oil to the re-
quired level with an approved oil.For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.Display
Possible cause/consequence
Possible solution
Check
Engine Oil Level
(Add 1 quart)
(USA only)
Check
Engine Oil Level
(Add 1 Liter)
(Canada only)
S 600 and S 65 AMG only:
The engine oil level is too low.
Check the engine oil level (
page 575) and
add engine oil as required (page 578).
If you must add engine oil frequently, have
the engine checked for possible leaks.
Check
Engine Oil Level
at Next Refueling
All models except S 600 and S 65 AMG:
The engine oil level has dropped to approx-
imately the minimum level.
Check the engine oil level (
page 575) and
add engine oil as required (page 578).
If you must add engine oil frequently, have
the engine checked for possible leaks.
!
Engine oil level warnings should not be ig-
nored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz Limit-
ed Warranty.
Page 697 of 801
696 Practical hintsWhat to do if …?Display
Possible cause/consequence
Possible solution
Engine Oil Level
Cannot Be
Measured
S600 and S65AMG only:
The measuring system is malfunctioning.
Have the measuring system checked by an
authorized Mercedes-Benz Center.
Engine Oil
Level Too High
S600 and S65AMG only:
You have added too much engine oil.
There is a risk of damaging:
the engine
the catalytic converter
Have excess oil siphoned or drained off. Con-
tact an authorized Mercedes-Benz Center.