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

620 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front pass. airbag
enabled
See Oper. ManualFront passenger front air bag is
activated while driving even
though a child, small individual,
or object below the system’s
weight threshold is on the front
passenger seat, or the front pas-
senger seat is empty. Objects
on the seat or forces acting on
the seat may make the system
sense supplemental weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Engage the electronic parking brake (page 395).
Switch off the ignition (page 344).
Remove child and child restraint from front passenger seat and properly
secure the child in rear seat employing the child restraint if necessary.
Remove any other items from on and around the front passenger seat and
make sure the storage bag on the back of the front passenger seat is emp-
ty.
Make sure that no objects which apply forces to the seat are present (e.g.
objects such as books, briefcases etc. lodged behind or around the seat,
head restraints pushing against roof etc.). The system may recognize such
forces as supplemental weight and sense that an occupant on the front
passenger seat is of a greater weight than actually present.
Keep the seat unoccupied, close the front passenger door and switch on
the ignition (
page 344).
Monitor the 59indicator lamp right of the instrument cluster
(
page 50) and the multifunction display in the instrument cluster
(
page 264) for the following:
(Continued on next page)

621 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front pass. airbag
enabled
See Oper. ManualWith the seat unoccupied and the ignition switched on (page 344),

the 59indicator lamp right of the instrument cluster should
illuminate and remain illuminated, indicating that the OCS (
page 47)
has deactivated the air bag.

the message “Front passenger airbag enabled See Oper. Manual” or the
message “Front passenger airbag disabled See Oper. Manual” should not
appear in the multifunction display at any time the seat is unoccupied.
Wait at last 60 seconds for the system to complete the necessary check
cycles and to make sure neither message appears in the multifunction dis-
play.
If above conditions are met, you can occupy the front passenger seat again.
Depending on the front passenger classification sensed by the OCS
(
page 47), the 59indicator lamp will remain illuminated or go
out.
If above conditions are not met, the system is not working properly. Have the
system checked as soon as possible by an authorized Mercedes-Benz Center.
Warning!G
If the 59indicator lamp re-
mains illuminated with an adult occupant on
the front passenger seat even after
performing the above corrective steps, do
not have any passenger use the front pas-
senger seat until the system has been re-
paired.

622 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Next Service X
due in ... days
due in ... mls (km)Service X must be carried out in ... days or
after ... miles (kilometers) (
page 582).
Have the maintenance service carried out by an authorized
Mercedes-Benz Center.
Only shift to
position 'P' when
vehicle is stationaryYou have tried to shift the automatic trans-
mission to P using the gear selector lever al-
though the vehicle is still in motion.Stop your vehicle as soon as it is safe to do so.
Shift the automatic transmission to park positionP.
Engage the electronic parking brake (page 395).
Park Assist
currently unavailable
See Oper. ManualPark Assist* is deactivated because the
area around the sensors* in the front or the
rear bumper (
page 590) is dirty.
Clean the front and rear bumper (page 590).
Park Assist* is deactivated because the
battery voltage is insufficient.Have the battery checked by an authorized Mercedes-Benz
Center.
Park Assist* is switched off because the ra-
dar sensor system* is temporarily inopera-
tive due to electromagnetic interference
near television and radio transmitter sta-
tions, toll stations, speed measuring sys-
tems, etc.Wait until the message in the multifunction display disappears.
Park Assist
inoperativePark Assist* is unavailable due to a mal-
function.Contact an authorized Mercedes-Benz Center as soon as pos-
sible.

623 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
PRE-SAFE
inoperative
See Oper. ManualPRE-SAFE® itself has failed. All other occu-
pant safety systems, such as the air bags,
are still available.Contact an authorized Mercedes-Benz Center as soon as pos-
sible.
Radar sensor
deactivated
See Oper. ManualYou attempt to activate DISTRONIC Plus*,
Park Assist* or PRE-SAFE® Brake* even
though you have switched off the radar sen-
sors* on the vehicle.
Check if the radar sensors* may be switched on (page 282).
Switch on the radar sensors* using the instrument cluster
control system.
Check tire pressures
and then restart
Run Flat Indicator
(Canada only)There was a warning message about a loss
in tire inflation pressure and the Run Flat In-
dicator has not been reactivated yet.Check and adjust tire inflation pressure as required
(
page 560).
Then reactivate the Run Flat Indicator (page 566).
Run Flat Indicator
inoperative
(Canada only)The Run Flat Indicator is malfunctioning.Contact an authorized Mercedes-Benz dealer as soon as pos-
sible.
Service X
dueService X must be carried out (page 582).Have the maintenance service carried out by an authorized
Mercedes-Benz Center.
Service X exceeded
by X days
by XXX mls (km)Service X must be carried within the next ...
or before you have driven ... miles (kilome-
ters) (
page 582).
Have the maintenance service carried out by an authorized
Mercedes-Benz Center as soon as possible.

624 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Shift to P or N
to start engineYou have attempted to start the engine
while the automatic transmission was set to
position R or D.Shift the automatic transmission to P or N (page 399).
Tire pressure
Check tiresThe pressure has fallen significantly 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 560).
If necessary, change the wheel (page 686).
Reactivate the Run Flat Indicator after adjusting the tire infla-
tion pressure values (
page 566).
Tire pressure monitor
inoperativeThe Advanced TPMS* or a wheel sensor is
malfunctioning.Have the Advanced TPMS* checked by an authorized
Mercedes-Benz Center.
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. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.

625 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Tire pressure monitor
inoperative
No wheel sensorsThe Advanced TPMS* is deactivated be-
cause wheels without proper sensors were
installed.Have the wheel sensors installed by an authorized
Mercedes-Benz Center.
As soon as all wheels with sensors have been mounted, the
Advanced TPMS* is switched back on after driving for sever-
al minutes.
Tire pressure monitor
currently unavailableThe Advanced TPMS* is unable to monitor
the tire inflation pressure due to:

a nearby radio interference source

the on-board voltage is too low

excessive wheel sensor temperatures
As soon as the causes for the malfunction are no longer present,
the Advanced TPMS* automatically becomes active again after
a few minutes driving.
Tire pressures
displayed after driving
a few minutesVehicles with Advanced TPMS*:
The tire inflation pressure is being checked.Drive the vehicle for a few minutes.
Visit workshop
without shifting gearsThe automatic transmission cannot be shift-
ed out of the set position because of a mal-
function.If the automatic transmission is shift to drive positionD
(
page 399):
Without changing the automatic transmission from drive
positionD, contact an authorized Mercedes-Benz Center.
If the automatic transmission is shift to positionN, R or P:
Do not drive.
Consult an authorized Mercedes-Benz Center.

626 Practical hints
What to do if …?
Symbol messages
Display Possible cause/consequencePossible solution
Malfunction
Stop Vehicle!You have started driving although the vehi-
cle level is still too low.
The vehicle is raised. The ABC* message
goes out after a few seconds.Stop your vehicle as soon as it is safe to do
so.
Engage the electronic parking brake
(
page 395).
Wait until the message disappears from the
multifunction display.
You may then drive off.
The vehicle is losing oil.
The ABC* message is continuously shown.Stop your vehicle as soon as it is safe to do
so.
Engage the electronic parking brake
(
page 395).
Call Roadside Assistance.
Or
Contact an authorized Mercedes-Benz
Center.

627 Practical hints
What to do if …?
Malfunction
Stop Vehicle!ABC* is malfunctioning.
The ABC* message is continuously shown.Do not turn steering wheel too far to avoid
damaging the front fenders.
Listen for scraping noises.
Do not exceed a speed of 50 mph (80 km/h).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Display Possible cause/consequencePossible solution

628 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
MalfunctionThe capability of the ABC* system is re-
stricted. This can impair the handling.Do not exceed a speed of 50 mph (80 km/h).
Contact an authorized Mercedes-Benz Cen-
ter as soon as possible.
Vehicle rising
Please wait a momentThe vehicle’s level is too low while at a
standstill. The vehicle will be raised.Do not drive off.
Wait until the message disappears from the
multifunction display.
You may then drive off.
ABS and ESP
inoperative
See Oper. ManualABS, ESP® as well as PRE-SAFE® are
switched off due to a malfunction. BAS is
also switched off.
The brake system is still functioning nor-
mally but without the ABS available.
BAS Plus* and PRE-SAFE
® Brake* are also
not available.
Continue driving with added caution. Wheels
may lock during hard braking, reducing steer-
ing 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.

629 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
ABS and ESP
currently unavailable
See Oper. ManualABS, ESP® as well as PRE-SAFE® are not
available due to a malfunction. BAS is also
switched off. It is possible that the self-diag-
nostics have not yet been completed.
The brake system still functions normally.
BAS Plus* and PRE-SAFE
® Brake* are also
not available.
Drive a short distance with gentle turns
above a speed of 12 mph (20 km/h).
The message disappears when ABS and ESP
®
are again available.
The ABS, ESP® as well as PRE-SAFE® were
deactivated because of insufficient power
supply. The charging voltage has fallen be-
low 10 volts.
The brake system still functions normally
but without the ABS, ESP
® and PRE-SAFE®
available.
BAS Plus* and PRE-SAFE
® Brake* are also
not available.
When the voltage is above this value again, the
ABS, ESP® and PRE-SAFE® are operational again
and the message in the multifunction display
should disappear.
If the message in the multifunction display does
not disappear:
Have the generator (alternator) and the bat-
tery checked.