Page 369 of 505

368 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
;
3 (USA only)
(Canada only)The red brake warning lamp
comes on while driving and
you hear a warning sound.You are driving with the parking
brake set.Release the parking brake
(
page 52).
The red brake warning lamp
comes on while driving.There is insufficient brake fluid
in the reservoir.Risk of accident! Carefully stop the
vehicle and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
Warning!G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Do not add
brake fluid before checking the brake
system.
Overfilling the brake fluid reservoir can re-
sult in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You
could be seriously burned.
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks.
Page 370 of 505

369 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
ú
±(USA only)
(Canada only)The yellow engine
malfunction indi-
cator lamp comes
on while driving.There is a malfunction in:
The fuel management system
The ignition system
The emission control system
Systems which affect emissions
Such malfunctions may result in ex-
cessive emissions values and may
switch the engine to its Limp-Home
Mode (emergency operation).
Have the vehicle checked as soon as possi-
ble by an authorized Mercedes-Benz Center.
An on-board diagnostic connector is used by
the service station to link the vehicle to the
shop diagnostics system. It allows the accu-
rate identification of system malfunctions
through the readout of diagnostic trouble
codes. It is located in the front left area of the
footwell next to the parking brake pedal.
iIn some states you may be required by law
to have the vehicle serviced immediately as soon
as the engine malfunction indicator lamp comes
on. Check local requirements.
Page 381 of 505

380 Practical hints
What to do if …?
Text messages
Display messagePossible cause/consequencePossible solution
ABSABS, ESP
inoperative
See Operator’s Man.The ABS and ESP® are not available due to
a malfunction.
The BAS is also deactivated.
The brake system is still functioning
normally but without but without the
systems specified above.Continue driving with added caution.
Wheels will lock during hard braking,
reducing steering capability.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of an accident.
Cruise con-
trol and
SPEEDTRONICinoperativeCruise control is malfunctioning.Have the cruise control checked by an au-
thorized Mercedes-Benz Center.
ESPinoperative
See Operator’s Man.The ESP® has switched off due to a
malfunction.
The ABS and the BAS might not be opera-
tional.
The brake system is still functioning
normally but without the systems speci-
fied above.Continue driving with added caution.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
Page 382 of 505

381 Practical hints
What to do if …?
Display messagePossible cause/consequencePossible solution
ESPunavailable
See Operator’s Man.The ESP® is temporarily not available.
The system’s self-diagnosis may not be
completed yet.
The ABS and the BAS might not be
operational.
The brake system is still functioning normally
but without the systems specified above.Drive a short distance with added
caution at a vehicle speed of above
12 mph (20 km/h).
When the message disappears, the
ESP
® is available again.
If the message does not disappear:
Continue driving with added caution.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon as
possible.
Failure to follow these instructions increas-
es the risk of an accident.
The charging voltage has fallen below 10 volts.
The ESP® has switched off.
The BAS may be switched off, too. The battery
may not be charged. The battery or the gener-
ator may be malfunctioning.
The ABS might not be operational.
The brake system is still functioning normally
but without the systems specified above.
Continue driving with added caution.
When the voltage is above this value
again, the ESP
® is operational again.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon as
possible.
Page 388 of 505

387 Practical hints
What to do if …?
Display messagePossible cause/consequencePossible solution
Run Flat Indicator
inactiveRun Flat Indicator* is malfunctioning
or has been switched off due to an
error.Have the Run Flat Indicator* checked by an autho-
rized Mercedes-Benz Center.
Check tires
Then reactivate
Run Flat IndicatorThere was a warning message about a
loss in the tire inflation pressure and
the Run Flat Indicator* has not been
reactivated yet.Make sure that the correct tire inflation pressure is
set for each tire.
Then reactivate the Run Flat Indicator*.
Tire pressure
Check tiresThe Run Flat Indicator* indicates that
the pressure is too low in one or more
tires.Carefully bring the vehicle to a halt, avoiding
abrupt steering and braking maneuvers. Observe
the traffic situation around you.
Check and adjust tire inflation pressure as
required (
page 333).
If necessary, change the wheel (page 436).
Reactivate the Run Flat Indicator* after adjusting
the tire inflation pressure values (
page 335).
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle.
You may lose control of the vehicle. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
Page 390 of 505

389 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
2Brakepad wearThe brake pads have reached their wear
limit.Have the brake pads replaced as soon
as possible.
;(USA only)
!(Canada only)
Release parking
brakeYou are driving with the parking brake set.Release the parking brake
(
page 52).
3 Check brake
fluid levelThere is insufficient brake fluid in the res-
ervoir.Risk of accident! Stop the vehicle in a
safe location as soon as possible and
notify an authorized Mercedes-Benz
Center. Do not add brake fluid! This
will not solve the problem.
Warning!G
Driving with the message Check brake
fluid level
displayed can result in an ac-
cident. Have your brake system checked im-
mediately. Do not add brake fluid before
checking the brake system. Overfilling the
brake fluid reservoir can result in spilling
brake fluid on hot engine parts and the
brake fluid catching fire. You could be seri-
ously burned.
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks.!Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.
Page 392 of 505
391 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop, turn engine offThe coolant is too hot.
Among other possible causes, the
poly-V-belt could be broken.Stop the vehicle in a safe location or
as soon as it is safe to do so.
Apply the parking brake (page 58).
Turn off the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Contact
an authorized Mercedes-Benz Center.
If it is intact:
Wait for the message to disappear be-
fore restarting the engine.
Doing otherwise could result in seri-
ous engine damage that is not covered
by the Mercedes-Benz Limited War-
ranty.
(Continued on next page)
Page 396 of 505

395 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
A Reserve fuelThe fuel level has dropped below the re-
serve mark.Refuel at the next gas station
(
page 312).
I Remove keyYou have forgotten to remove the
SmartKey.Remove the SmartKey from the start-
er switch.
Replace keyNo additional code available for SmartKey
or SmartKey with KEYLESS-GO*.Contact an authorized Mercedes-Benz
Center as soon as possible.
Change
key batteriesThe SmartKey with KEYLESS-GO* batter-
ies are discharged.Change the batteries (page 425).
Key
not detectedThe SmartKey with KEYLESS-GO* is not
recognized while the engine is running be-
cause
the SmartKey is not in the vehicle
there is strong radio-frequency inter-
ference
Stop the vehicle as soon as it is safe to
do so.
Apply the parking brake (page 58).
Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine has been stopped.
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 necessary.