Page 285 of 416
285 Operation
Vehicle care
Cleaning the Distronic* system sensor
cover
1Distronic* system sensor cover
Use a mild car wash detergent, such as
Mercedes-Benz approved Car Shampoo,
with plenty of water to clean sensor
cover1.
To prevent scratches, never apply strong
force and use only a soft, non-scratchy
cloth when cleaning the sensor cover. Do
not attempt to wipe dirty sensors with a
dry cloth or sponge.Cleaning the Parktronic* system
sensors
1Parktronic sensors
Use a mild car wash detergent, such as
Mercedes-Benz approved Car Shampoo
with plenty of water.When using a steam cleaner or power
washer, aim nozzle only briefly from a min-
imum distance of 4 in. (10 cm) at
sensors1.
To prevent scratches, never apply strong
force and use only a soft, non-scratchy
cloth when cleaning the sensor. Do not at-
tempt to wipe dirty sensors with a dry cloth
or sponge.
iRestart the engine after cleaning sen-
sor cover1.
Page 293 of 416

293 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
;
(USA only)
3
(Canada only)The red brake warning lamp
lights up while driving and you
hear a warning sound.
You are driving with the parking brake set.
Release the parking brake
(page 44).
The red brake warning lamp
lights up while driving.
There is insufficient brake fluid in the reser-
voir.
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. Don’t 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
can 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 294 of 416

294 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
?
The yellow “CHECK ENGINE”
malfunction indicator 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 excessive
emissions values and may switch the engine
to its limp-home (emergency operation)
mode.
Have the vehicle checked as soon as
possible 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 sys-
tem. It allows the accurate identifica-
tion of system malfunctions through
the readout of diagnostic trouble
codes. It is located in the front left
area of the footwell next to the park-
ing brake pedal.
The fuel cap is not closed tightly.
Close the fuel cap.
Your gas tank is empty.
After refuelling, start the engine three
or four times in succession.
The limp-home mode is canceled. You do
not need to have your vehicle checked.
The yellow fuel tank reserve
warning lamp lights up while
driving.
The fuel level has gone below the reserve
mark.
Refuel at the next gas station
(page 261).
<
The red seat belt warning lamp
blinks for a brief period after
starting the engine.
The warning lamp reminds you to fasten seat
belts.
Fasten your seat belt.
Page 301 of 416
301 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a battery
charger or jump started.
Have the battery checked at a ser-
vice station.
The battery is no longer charging.
Possible causes:
Alternator malfunctioning
Broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be operat-
ing with restricted capability. Considerably
greater brake pedal force is required and
the stopping distance is longer.
Stop immediately and 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. Notify
an authorized Mercedes-Benz
Center.
If it is intact:
Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.
Page 302 of 416

302 Practical hintsWhat to do if …?Display
Possible cause
Suggested solution
2
BRAKE WEAR
VISIT WORKSHOP!
The brake pads have reached their wear
limit.
Have the brake pads replaced as
soon as possible.
Except Canada:;Canada only:3
BRAKE FLUID
VISIT WORKSHOP!
There is insufficient brake fluid in the reser-
voir.
Risk of accident! Stop the vehicle
and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Service Book-
let.
Warning!
G
Driving with this message displayed can re-
sult in an accident. Have your brake system
checked immediately. Don’t add brake fluid
before checking the brake system. Overfill-
ing the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and
the brake fluid catching fire. You can be se-
riously 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 303 of 416

303 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
F
CHIP CARD
CHECK BATTERY
KEYLESS-GO*card batteries are dis-
charged.
Change the batteries (
page 328).
CHIP CARD
NOT RECOGNIZED!
KEYLESS-GO*card is not recognized while
the engine is running because
the card is not in the vehicle
there is strong radio-frequency interfer-
ence
Stop the vehicle as soon as it is safe
to do so.
Search for the card.
Otherwise the vehicle cannot be central-
ly locked nor can the engine be started
again after it has been stopped.
KEYLESS-GO*card is momentarily not rec-
ognized.
Change the position of the card in
the vehicle.
Operate the vehicle with the
SmartKey in the ignition if necessary.
CHIP CARD
DETECTED IN VEHICLE
KEYLESS-GO*card left in the vehicle was
recognized while locking the vehicle from
the outside.
Take the card out of the vehicle.
CHIP CARD
VISIT WORKSHOP!
The KEYLESS-GO* system is malfunction-
ing.
Visit an authorized Mercedes-Benz
Center as soon as possible.
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304 Practical hintsWhat to do if …?Display
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Suggested solution
F
CHIP CARD
DO NOT FORGET
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 ignition.
Message is only a reminder.
Insert SmartKey in the ignition.
Take the KEYLESS-GO*card with you
when leaving the vehicle.
B
COOLANT
CHECK LEVEL!
The coolant level is too low.
Add coolant (
page 268).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Cen-
ter.
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 a sufficient
amount of coolant in the cooling sys-
tem. The engine will overheat, causing
major engine damage.
Page 305 of 416

305 Practical hints
What to do if …?
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display
Possible cause
Suggested solution
Ï
COOLANT
STOP, ENGINE OFF!
The coolant is too hot.
Stop the vehicle and turn off the en-
gine.
Only start the engine again after the
message disappears. You could oth-
erwise damage the engine.
Warning!
G
Driving when your engine is badly overheat-
ed 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 and can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until it
cools down.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by
the Mercedes-Benz Limited Warranty.