2004 MERCEDES-BENZ C320 COUPE brake system

235 Operation
At the gas station
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 237).
Opening hood, see (
page 236).
Coolant
For normal replenishing, use water (pota-
ble water quality). For more information on
coolant, see “Coolant level” (
page 241)Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 293).
Exterior lamp switch (
page 98).
Tire inflation pressure
For information on tire inflation pressure,
see “Checking tire inflation pressure”
(
page 245).
!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 immediately. Noti-
fy an authorized Mercedes-Benz Center
immediately. Do not add brake fluid as
this will not solve the problem. For
more information, see “Practical Hints”
(page 259).

258 Practical hintsWhat to do if …
What to do if …Lamps in instrument clusterGeneral information:
If a bulb in the instrument cluster fails to
come on during the bulb self-check when turning the SmartKey in the starter switch
to position2, have it checked and replaced
if necessary.Problem
Possible cause
Suggested solution
-
The yellow ABS malfunction
indicator lamp comes on while
driving.
The ABS has detected a malfunction and has
switched off. The BAS and the ESP are also
switched off (see messages in display).
The brake system is still functioning normally
but without the ABS available.

Continue driving with added caution.
Wheels may 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
increases the risk of an accident.

Read and observe messages in the
display (
page 264).
The charging voltage has fallen below ten
volts. The ABS has switched off.

When the voltage is above this value
again, the ABS is operational again.

If necessary, have the generator
(alternator) and battery checked.

259 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
3
(Canada only)
;
(USA 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 46).
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. Don’t 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 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.

260 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
parking brake pedal.
The fuel cap is not closed tight.

Check 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.

265 Practical hints
What to do if …
Text messagesDisplay message
Possible cause
Possible solution
BAS
BRAKE ASSIST
NOT AVAILABLE!
The charging voltage has fallen below ten
volts. The BAS has switched off.

When the voltage is above this value
again, the BAS is operational again.

If necessary, have the generator and
battery checked.
BRAKE ASSIST
VISIT WORKSHOP!
The BAS has detected a malfunction and
switched off. The brake system is still
functioning normally but without the BAS
available.

Continue driving with added caution.

Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions
increases the risk of an accident.
DISPLAY MALFUNCTION
VISIT WORKSHOP!
The BAS or the BAS display is
malfunctioning.

Continue driving with added caution.

Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions
increases the risk of an accident.

268 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display message
Possible cause
Possible solution
-
ABS SYSTEM
VISIT WORKSHOP!
The ABS has detected a malfunction and
has switched off. The ESP and the BAS
are also deactivated.
The brake system is still functioning
normally but without the ABS available.

Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.

Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions
increases the risk of an accident.
DISPLAY MALFUNCTION
VISIT WORKSHOP!
The ABS or the ABS display is
malfunctioning.

Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.

Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions
increases the risk of an accident.

270 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
2
BRAKE WEAR
VISIT WORKSHOP!
The brake pads have reached their wear
limit.

Have the brake pads replaced as soon
as possible.
3
BRAKE FLUID
VISIT WORKSHOP!
There is insufficient brake fluid in the
reservoir.

Risk of accident! 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 this message displayed can
result in an accident. Have your brake
system checked immediately. 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 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.
!Brake pad thickness must be visually
checked by a qualified technican at the
intervals specified in the Service
booklet.

277 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
A
RESERVE FUEL
GO TO GAS STATION!
The fuel level has dropped below the
reserve mark.

Refuel at the next gas station
(page 233).
CHECK GAS CAP!
SEE OPERATOR’S MANUAL
The fuel cap is not closed tightly.

Check the fuel cap.
Y
HOOD OPEN!
You are driving with the hood open.

Close the hood (
page 236).
I
REMOVE KEY!
You have forgotten to remove the
SmartKey.

Remove the SmartKey from the starter
switch.
REPLACE KEY!
DRIVE TO WORKSHOP!
No additional code available for
SmartKey.

Change the SmartKey.
.
3RD BRAKE LIGHT
CHECK LIGHT!
The high mounted brake lamp is
malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
AUTOM. LIGHT ON
REMOVE KEY!
SmartKey in starter switch position1
or2.

Remove SmartKey from the starter
switch.
BRAKE LIGHT
DRIVE TO WORKSHOP!
Brake lamp illumination is delayed or
lamp is permanently on.

Visit an authorized Mercedes-Benz
Center as soon as possible.
BRAKE LIGHT, L
CHECK LIGHT!
The left brake lamp is malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
BRAKE LIGHT, R
CHECK LIGHT!
The right brake lamp is malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
DISPLAY MALFUNCTION
VISIT WORKSHOP!
The display for the lamps or the system is
malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.