2008 MERCEDES-BENZ ML550 parking brake

403 Practical hints
What to do if …
ProblemPossible cause/consequenceSuggested solution
?(USA only)
±(Canada only)
The yellow engine malfunc-
tion 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 opera-
tion) mode.
Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics
system. It allows the accurate identi-
fication 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.
iSome states may by law require you to visit
a workshop as soon as the engine malfunction
indicator lamp comes on. Check local require-
ments.

416 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ABSUnavailable
See Operator’s ManualThe self-diagnosis has not yet been
completed yet.The display will clear after driving a
short distance at a vehicle speed of
above 12 mph (20 km/h).
Cruise Control And
SPEEDTRONICInoperativeThe cruise control is malfunctioning.Have cruise control checked by an
authorized Mercedes-Benz Light
Truck Center.
Cruise Control––– MPHYou have attempted to set a speed
while driving below 20 mph
(30 km/h).Accelerate to a speed exceeding
20 mph (30 km/h) and set the
speed (
page 244).
The ESP® is switched off.Switch on the ESP® (page 100).
The automatic transmission is set to
positionP, R, orN.Set the automatic transmission to
positionD (
page 185).
The vehicle is secured with the
parking brake.Release the parking brake
(
page 57).

417 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
Depress brake
to shift out of P.You have tried to shift the automatic
transmission into positionD,R orN
using the gear selector lever without
depressing the brake pedal.Depress the brake pedal.
Door Open
Vehicle Not In ParkYou have opened the driver’s door
and the automatic transmission is
still in positionD,R orN.Before you leave the vehicle, make sure
that the automatic transmission is set to
positionP and that the parking brake is
engaged.
Drive to workshop
without
shifting gears.The automatic transmission cannot
be shifted out of the set position be-
cause of a malfunction.If the automatic transmission is set to
positionD:
Without changing the automatic transmis-
sion from positionD, drive to an authorized
Mercedes-Benz Light Truck Center.
If the automatic transmission is set to
positionN,R orP:
Do not drive.
Contact an authorized Mercedes-Benz Light
Truck Center.

420 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
PShift to P or N
to start engine.You have attempted to start the
engine with the KEYLESS-GO*
start/stop button while the auto-
matic transmission was set to
positionR orD.Set the automatic transmission to
positionP orN.
Make sure the brake pedal is depressed
when attempting to start the engine with
the KEYLESS-GO* start/stop button.
Only shift to P
when vehicle
is at a standstill.You have tried to shift the automatic
transmission into positionP using
the gear selector lever although the
vehicle is still in motion.Stop the vehicle.
Apply the parking brake (page 65).
SRSRestraint Sys. Malfunction
Service RequiredThe system is malfunctioning.Drive with added caution to the nearest
authorized Mercedes-Benz Light Truck
Center.
Warning!G
In the event a malfunction of the SRS is indi-
cated as outlined above, the SRS may not be
operational. For your safety, we strongly
recommend that you contact an authorized
Mercedes-Benz Light Truck Center immedi-
ately to have the system checked; otherwise
the SRS may not be activated when needed
in an accident, which could result in serious
or fatal injury, or it might deploy unexpect-
edly and unnecessarily which could also re-
sult in injury.

421 Practical hints
What to do if …
Display messagePossible
cause/consequencePossible solution
Front Passenger Airbag
Enabled
See Operator’s 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 passenger seat is
empty. Objects on the seat or
forces acting on the seat may
make the system sense sup-
plemental weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Apply the parking brake (page 65).
Switch off the ignition (page 40).
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 empty.
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 recog-
nize 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 40).
(Continued on next page)

423 Practical hints
What to do if …
Display messagePossible cause/conse-
quencePossible solution
Front Passenger Airbag
Disabled
See Operator’s ManualFront passenger front air bag is
deactivated while driving even
though an adult or someone
larger than a small individual is
occupying the front passenger
seat. Forces acting on the seat
may make the system sense a
decrease in weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Apply the parking brake (page 65).
Switch off the ignition (page 40).
Have the front passenger vacate the seat and exit the vehicle.
Adjust the seat in a height position (page 44).
Make sure that no objects which apply forces to the seat are present
(e.g. objects such as books, briefcases etc. lodged underneath, behind
or around the seat). Such forces may cause the system to sense that
an occupant of a lesser weight than actually present is on the front
passenger seat.
Keep the seat unoccupied, close the front passenger door and switch
on the ignition (
page 40).
(Continued on next page)

427 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
ò Replace air filter.The air filter is clogged.Have the air filter checked by an authorized
Mercedes-Benz Light Truck Center.
#The battery is no longer charging.
Possible causes:

alternator malfunctioning

broken poly-V-belt
Do not forget that the brake system
requires electrical energy and may be
operating with restricted capability.
Considerably greater brake pedal
force is required and the stopping dis-
tance is increased.
Stop the vehicle in a safe location or as soon as
it is safe to do so.
Apply the parking brake (page 65).
 Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the engine
will overheat due to an inoperative water pump
which may result in damage to the engine.
Contact an authorized Mercedes-Benz Light
Truck Center.
If it is intact:
Drive immediately to the nearest authorized
Mercedes-Benz Light Truck Center. Adjust
driving to be consistent with reduced braking
responsiveness.

428 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
#Battery / Alternator
Stop VehicleThe battery is defective.Stop the vehicle in a safe location or as
soon as it is safe to do so.
Apply the parking brake (page 65).
Do not continue to drive.
Contact an authorized Mercedes-Benz
Light Truck Center.
{InoperativeDownhill Speed Regulation is
malfunctioning.Have the Downhill Speed Regulation
checked by an authorized Mercedes-Benz
Light Truck Center.
2Brake WearThe brake pads have reached
their wear limit.Have the brake pads replaced as soon as
possible.
!Brake pad thickness must be visually in-
spected by a qualified technician at the intervals
specified in the Maintenance Booklet.