Page 404 of 521

403 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
ú
(USA only)
±
(Canada only)
Engine
Service
There may be a malfunction in the:
fuel injection system
ignition system (Gasoline engine)
exhaust system
fuel system
Have the measuring system checked
by an authorized Mercedes-Benz
Center.
B
Coolant
Check level
The coolant level is too low.
Add coolant (
page 325).
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 can 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 Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major en-
gine damage.
Page 406 of 521
405 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
Ï
Coolant
Stop, 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.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative wa-
ter pump which may result in damage to the
engine. Notify an authorized Mercedes-Benz
Center.
If it is intact:
Do not continue to drive the vehicle with
this message displayed. Doing so could re-
sult in serious engine damage that is not
covered by the Mercedes-Benz Warranty.
Drive immediately to the nearest authorized
Mercedes-Benz Center.
Coolant
Visit workshop
The cooling fan for the coolant is malfunc-
tioning.
Observe the coolant temperature display.
Have the fan replaced as soon as possible.
Page 408 of 521

407 Practical hints
What to do if …
When the message
Add 1 Qt.
(Canada:
1 Liter
) engine oil at next
refueling
(E320CDI, E500, E55AMG)
or
Check oil level at next refueling
(E 350) appears while the engine is run-
ning and at operating temperature, the en-
gine oil level has dropped to approximately
the minimum level.When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest ser-
vice station where the engine oil should be
topped to the required level with an ap-
proved oil specified in the Factory Ap-
proved Service Products pamphlet.
Display symbol
Display messages
Possible cause/consequence
Possible solution
:
USA only:Add 1 Qt. engine oil
at next refuelingCanada only:Add 1 Liter engine oil
at next refueling
E 320 CDI, E 500, E 55 AMG only:
The engine oil level is too low.
Check the engine oil level
(page 321) and add engine oil as re-
quired (
page 323).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
Check oil level
at next refueling
E 350 only:
The engine oil has dropped to a critical
level.
Check the engine oil level
(page 322) and add oil as required
(page 323).
If you must add engine oil frequently,
have the engine checked for possible
leaks.!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Page 409 of 521
408 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
:
Engine oil level
Stop, engine off
E 320 CDI, E 500, E 55 AMG only:
There is no oil in the engine. There is a
danger of engine damage.
Carefully bring the vehicle to a halt as
soon as possible.
Turn off the engine.
Add engine oil (
page 323) and
check the engine oil level
(
page 321).
Engine oil level
Visit workshop
E 320 CDI, E 500, E 55 AMG only:
The engine oil has dropped to a critical
level.
Check the engine oil level
(page 322) and add oil as required
(page 323).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
Change engine oil
Visit workshop
E 320 CDI, E 500, E 55 AMG only:
It may be that there is water in the engine
oil.
Have the engine oil and the cooling
system checked.
Page 410 of 521
409 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
:
Engine oil level
Reduce oil level
E 320 CDI, E 500, E 55 AMG only:
You have added too much engine oil.
There is a risk of damaging:
the engine
the catalytic converter
Have oil siphoned or drained off. Ob-
serve all legal requirements with re-
spect to its disposal.
Oil sensor malfunction
Visit workshop
E 320 CDI, E 500, E 55 AMG only:
The measuring system is malfunctioning.
Have the measuring system checked
by an authorized Mercedes-Benz
Center.
Change engine oil
Visit workshop
E 320 CDI, E 500, E 55 AMG only:
It may be that there is water in the engine
oil.
Have the engine oil and the cooling
system checked.
Page 411 of 521

410 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
Y
Hood open
You are driving with the hood open.
Close the hood (
page 319).
F
Key
Check battery
The SmartKey with KEYLESS-GO* batter-
ies are discharged.
Change the batteries (
page 431).
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 in a safe location 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 412 of 521

411 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
F
Do not
forget key
This display appears (for a maximum of
60 seconds) if the driver’s door is opened
with the engine shut off and no SmartKey
in the starter switch.
This message is only a reminder.
Insert SmartKey in the starter switch.
Take the SmartKey with
KEYLESS-GO* with you when leaving
the vehicle.
Remove key
You have forgotten to remove the
SmartKey.
Remove the SmartKey from the start-
er switch.
Replace key
There is no additional code available for
SmartKey or SmartKey with
KEYLESS-GO*.
Visit an authorized Mercedes-Benz
Center as soon as possible.
A
Reserve fuel
The fuel level has dropped below the re-
serve mark.
Refuel at the next gas station
(page 315).
Check gas cap
See Operator’s Manual
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 315).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an
authorized Mercedes-Benz Center.
Page 452 of 521

451 Practical hints
Batteries
Disconnecting 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 trunk.
!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 electrohydraulic 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
“Electrohydraulic brake system”
(page 97).
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