MERCEDES-BENZ S550 4MATIC 2008 W221 Owner's Manual

630 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Check brake
fluid levelThere is insufficient brake fluid in the reser-
voir.Risk of accident!
Carefully stop the vehicle in a safe location or
as soon as it is safe to do so.
Engage the electronic parking brake
(
page 395).
Contact an authorized Mercedes-Benz Cen-
ter.
Do not add brake fluid! This will not solve the
problem.
(USA only)
(Canada only)
Warning!G
Driving with the message “Check brake fluid
level ” displayed can result in an accident.
Have your brake system checked immedi-
ately. Do not add brake fluid before check-
ing the brake system. Overfilling the brake
fluid reservoir can result in spilling brake flu-
id 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.

631 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Brake immediatelyA malfunction has occurred while
DISTRONIC Plus* was switched on.While observing surrounding traffic condi-
tions and when it is safe, immediately de-
press the brake pedal firmly until the warning
message disappears.
Engage the electronic parking brake
(
page 395).
(USA only)
(Canada only)
EBV, ABS, ESP
inoperative
See Oper. ManualESP®, EBP and ABS are switched off due to
a malfunction. BAS is also switched off. As
a result, PRE-SAFE
® is also inoperative.
BAS Plus* and PRE-SAFE
® Brake* are also
not 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.
(USA only)
(Canada only)

632 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Service
See Oper. ManualS 600 and S 65 AMG only:
The brake system sensors are malfunction-
ing. The brake system continues to function
normally with full brake force boost.Continue driving with added caution.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
(USA only)
(Canada only)
Brake wearThe brake pads have reached their wear
limit.Have the brake pads replaced as soon as
possible.
!Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.

633 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Parking brake
See Oper. ManualThe red indicator lamp for the electronic
parking brake is either on or off and the yel-
low warning lamp for the electronic parking
brake comes on.
The electronic parking brake is malfunction-
ing.To release:
Pull handle of electronic parking brake
(
page 395).
or
Drive off carefully (page 395).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
or
Release electronic parking brake mechani-
cally (
page 673).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
To engage:
Switch off ignition and press handle for elec-
tronic parking brake until the warning mes-
sage on the multifunction display disappears.
(USA only)
(Canada only)

634 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Parking brake
See Oper. ManualThe red indicator lamp for the electronic
parking brake flashes.
The power supply for the electronic parking
brake was malfunctioning or the electronic
parking brake was previously mechanically
released.Pull handle for electronic parking brake
(
page 395).
or
Carefully drive off (page 395).
or
Press handle for electronic parking brake un-
til the warning message disappears from the
multifunction display.
(USA only)
(Canada only)

635 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Parking brake
See Oper. ManualThe red indicator lamp for the electronic
parking brake flashes and the yellow warn-
ing lamp for the electronic parking brake
lights up.
The electronic parking brake is malfunction-
ing.Switch ignition off and back on again, and en-
gage or release electronic parking brake
(
page 395).
or
Carefully drive off (page 395).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
or
Release electronic parking brake mechani-
cally (
page 673).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
(USA only)
(Canada only)

636 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Parking brake
See Oper. ManualWhen you engage or release the electronic
parking brake, the red indicator lamp for
the electronic parking brake flashes for
approx.10 seconds. Afterward, it goes out
or lights up continuously. The yellow warn-
ing lamp for the electronic parking brake
lights up.
The electronic parking brake is malfunction-
ing or overheated for example due to over-
or undervoltage.Carefully drive off (page 395).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
In the event of overvoltage or undervoltage:
Remove the cause of the overvoltage or und-
ervoltage, e.g. charge the battery or restart
the engine.
Switch ignition off and back on again, and en-
gage or release electronic parking brake
(
page 395).
If the electronic parking brake still cannot be re-
leased:
Release electronic parking brake mechani-
cally (
page 673).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
(Continued on next page)
(USA only)
(Canada only)

637 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Parking brake
See Oper. ManualIf overheated:
Let vehicle cool down, and do not engage
electronic parking brake during this time.
or
Switch ignition off and back on again, and en-
gage or release electronic parking brake.
(USA only)
(Canada only)Parking brake
inoperativeWhen you engage or release the electronic
parking brake, the red indicator lamp for
the electronic parking brake flashes and
goes out after approx. 10 seconds. The yel-
low warning lamp for the electronic parking
brake lights up.
The electronic parking brake is malfunction-
ing.Switch ignition off and back on again, and en-
gage electronic parking brake (
page 395).
If the electronic parking brake cannot be en-
gaged:
Shift the automatic transmission to P
(
page 399).
Protect vehicle from rolling away while
parked by using a chock from the vehicle tool
kit (
page 670).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.

638 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Please release
parking brakeThe red indicator lamp for the electronic
parking brake flashes and you also hear a
warning signal.
You are driving with the electronic parking
brake activated, or you are carrying out an
emergency brake application with the elec-
tronic parking brake (
page 395).
Release electronic parking brake.
or
Carefully drive off (page 395).
or
Release the handle for electronic parking
brake.
(USA only)
(Canada only)Please release
parking brakeThe red indicator lamp for the electronic
parking brake flashes and the yellow warn-
ing lamp for the electronic parking brake
comes on. You also hear a warning tone.
The electronic parking brake is malfunction-
ing; braking action is restricted.While driving:
Release the handle for electronic parking
brake.
While at a standstill:
Switch off ignition and press handle for elec-
tronic parking brake until the warning mes-
sage disappears from the multifunction
display.

639 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Turn on the ignition
to release the
parking brakeThe yellow indicator lamp for the electronic
parking brake comes on.
You have tried to release the electronic
parking brake, but the ignition was not
switched on.Switch on the ignition (page 344).
(USA only)
(Canada only)
Inoperative
See Oper. ManualESP® a s w e l l a s P R E - S A F E® are switched off
due to a malfunction. In addition, the v
warning lamp in the instrument cluster
comes on.
The ABS may not be operational and the fol-
lowing systems are not available:

BAS and BAS Plus*

PRE-SAFE® Brake*

Distronic Plus*

Cruise control

Hill start assist system
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.