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319 Practical hints
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Front passenger
airbagenabled
See Oper. ManualThe passenger front air bag and
the passenger knee air bag are
activated while driving even
though a child, small individual,
or object below the system’s
weight threshold is on the pas-
senger seat, or the passenger
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 passenger seat for the following:
Switch off the ignition (page 40).
Apply the parking brake (page 55).
Remove child and child restraint from passenger seat.
Make sure that no objects which are applying supplemen-
tal weight onto the seat are present. The system may rec-
ognize such supplemental weight and sense that an
occupant on the passenger seat is of a greater weight
than actually present.
Keep the seat unoccupied, close the passenger door and
switch on the ignition (
page 40).
Monitor the PASSENGER AIR BAG OFF indicator lamp
(
page 70) and the multifunction display in the instrument
cluster (
page 117) for the following:
(Continued on next page)
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321 Practical hints
What to do if ...
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Front passenger
airbagdisabled
See Oper. ManualThe passenger front air bag is
deactivated while driving even
though an adult or someone
larger than a small individual is
occupying the 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 passenger seat for the following:
Switch off the ignition (page 40).
Apply the parking brake (page 55).
Have the passenger vacate the seat and exit the vehicle.
Keep the seat unoccupied, close the passenger door and
switch on the ignition (
page 40).
Monitor the PASSENGER AIR BAG OFF indicator lamp
(
page 70) and the multifunction display in the instrument
cluster (
page 117) for the following:
With the seat unoccupied and the ignition switched on,
the PASSENGER AIR BAG OFF indicator lamp (page 70)
should illuminate and remain illuminated, indicating that
the OCS (
page 67) has deactivated the passenger front
air bag and the passenger knee air bag.
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324 Practical hints
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Tire pressure
monitorreactivatedThe TPMS is using the current pressure
values as the basis for monitoring.
Tire pressuredisplayed only
after driving
a few minutesThe tire inflation pressure is being checked.Drive the vehicle for a few minutes.
Tire pressuredisplayed only
when ignition
is switched onSwitch on the ignition (page 40).
Tire pressure
monitortemporarily
unavailableThe tire inflation pressure monitor is unable
to monitor the tire inflation pressure due to
the presence of several wheel sensors in
the vehicle.
excessive wheel sensor temperatures.
a nearby radio interference source.
unrecognized wheel sensors mounted.
Remove any extra wheel sensors
from the vehicle.
As soon as the causes of the malfunc-
tion have been removed, the TPMS auto-
matically becomes active again.
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. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
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325 Practical hints
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Reactivate
tire pressure
monitorafter correcting
tire pressureThere was a tire inflation pressure warning
message.
The low tire pressure telltale for the TPMS
comes on and you have not reactivated the
system since the last tire inflation pressure
warning message.Reactivate the TPMS after correcting
the tire inflation pressure values
(
page 271).
Tire pressure
monitor
inoperativeDrive to
workshopThe TPMS is malfunctioning. Have the TPMS checked by an
authorized Mercedes-Benz Center.
A wheel without proper sensor was
installed.Have the wheel checked.
Please correct
the tire pressureThe tire inflation pressure is too low in one
or more tires.Check and correct tire inflation
pressure as required (
page 268).
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. Contin-
ued driving with a flat tire will cause exces-
sive heat build-up and possibly a fire.
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327 Practical hints
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Symbol messages
Left displayRight displayPossible cause/
consequencePossible solution
malfunctionThe Airbrake locking mecha-
nism is malfunctioning.Contact an authorized Mercedes-Benz Center
immediately.
#Battery/Alternator
Stop carThe battery is malfunctioning.
The electro-hydraulic brake
system requires electrical
energy and therefore has only
limited operation. Considerably
greater brake pedal force is
required and the pedal travel is
longer. The stopping distance is
increased. If necessary, apply
full pressure to the brake pedal.Stop the vehicle as soon as it is safe to do so. Adjust
driving to be consistent with reduced braking
responsiveness.
Do not drive any further.
Call Roadside Assistance.
Contact an authorized Mercedes-Benz Center
immediately.
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328 Practical hints
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#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
pedal travel is longer. The stop-
ping distance is increased. If
necessary, apply full pressure
to the brake pedal.
Stop the vehicle immediately in a safe location and
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 Center.
If it is in order:
Contact an authorized Mercedes-Benz Center imme-
diately. Adjust driving to be consistent with reduced
braking responsiveness.
Read and observe additional messages in the
multifunction display.
The starter battery has been
charged with a battery charger
or jump started.Contact an authorized Mercedes-Benz Center.
There is a malfunction in the
electronic system.Have the system checked at an authorized
Mercedes-Benz Center immediately.
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TReduced
brake effect
Depress brake
pedal fully!The electro-hydraulic brake
system is in emergency opera-
tion mode. Considerably great-
er brake pedal force is required
and the pedal travel is longer.
The stopping distance is in-
creased. If necessary, apply full
pressure to the brake pedal.
The maximum speed is limited
to 55 mph (90 km/h).Stop the vehicle in a safe location or as soon as it is safe
to do so.
Apply the parking brake (page 55).
Do not drive any further.
Prevent the vehicle from rolling away by blocking the
wheels with wheel chocks or other sizeable objects.
Contact an authorized Mercedes-Benz Center.
or
Call for Roadside Assistance.
Warning!G
Driving while this message is displayed can
result in an accident. Have your brake
system checked immediately.
If the electro-hydraulic brake system enters
its emergency operation mode, the driver
must apply significantly greater brake pedal
pressure and depress the pedal much fur-
ther than normal to obtain braking effect.
If necessary, apply full pressure to the brake
pedal. Brakes are only applied to the front
wheels. Stopping distance is increased!
If there is a malfunction in the
electro-hydraulic brake system, we recom-
mend that the vehicle be transported with
all wheels off the ground using flatbed or ap-
propriate wheel lift/dolly equipment.A tow bar must be used if circumstances do
not permit the use of the recommended
towing methods and the vehicle requires
towing with all four wheels on the ground.
Towing the vehicle with all four wheels on
the ground is only permissible for distances
up to 30 miles (50 km) and at a speed not to
exceed 30 mph (50 km/h). For more infor-
mation, see “Towing the vehicle”
(
page 370).
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330 Practical hints
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consequencePossible solution
;(USA only)
3(Canada only)
Check
brake fluid levelRisk of accident!
There is insufficient brake fluid
in the reservoir.Stop the vehicle in a safe location or as soon as
it is safe to do so.
Do not drive any further.
Contact an authorized Mercedes-Benz Center.
Do not add brake fluid! This will not solve the
problem.
Warning!G
Driving with the message Check brake
fluid level
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.