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368 Practical hints
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Front Passeng.
AirbagEnabled
See Oper. ManualThe 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 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 63).
Remove child and child restraint from passenger seat.
Make sure that no objects which are applying supple-
mental weight onto the seat are present. The system
may recognize 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 5/indicator lamp (
page 78) and the
multifunction display in the instrument cluster (
page 143)
for the following:
(Continued on next page)
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370 Practical hints
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Left display Right display Possible cause/consequencePossible solution
Front Passeng.
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 63).
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 5/indicator lamp (
page 78) and the
multifunction display in the instrument cluster (
page 143)
for the following:
(Continued on next page)
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375 Practical hints
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Tire Pressure Monitor
Wheel Sensor MissingVehicles with Advanced TPMS*:
One or more wheels without
appropriate wheel sensors
mounted (e.g. spare wheel).
The respective tire is indicated by
--- instead of the tire inflation
pressure in the multifunction
display.
Have the Advanced TPMS* checked by an
authorized Mercedes-Benz Center.
Have appropriate wheel sensors installed
by an authorized Mercedes-Benz Center.
Tire Pressure MonitorCurrently
UnavailableThe TPMS or Advanced TPMS* is
unable to monitor the tire pres-
sure due to a nearby radio interfer-
ence source.As soon as the causes for the malfunction
are no longer present, the TPMS or
Advanced TPMS* automatically becomes
active again after a few minutes driving.
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.
Warning!G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
Page 377 of 489
376 Practical hints
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Symbol messages
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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 capa-
bility. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.
Stop the vehicle immediately in a safe loca-
tion 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 immediately. Adjust driving to be
consistent with reduced braking respon-
siveness.
There is a malfunction in the elec-
tronic system.Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
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# Battery/
Alternator
Stop CarThe battery is malfunctioning.
The electro-hydraulic brake system
requires electrical energy and
therefore has only limited opera-
tion. Considerably greater brake
pedal force is required and the stop-
ping distance is increased.Stop the vehicle in a safe location.
Adjust driving to be consistent with reduced
braking responsiveness.
Contact an authorized Mercedes-Benz
Center.
USA only:
;
Canada only:
3
Reduced
Brake Effect
Start EngineThe battery has insufficient voltage
and cannot supply sufficient power
to the electro-hydraulic brake sys-
tem.Start the engine.
The message disappears when sufficient
voltage is available.
Warning!G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and lead to death. Do not
run the engine in confined areas (such as a
garage) which are not properly ventilated.
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TReduced
Brake Effect
Depress brake
pedal fully.The electro-hydraulic brake system
is in emergency operation mode.
Considerably greater brake pedal
force is required and the brake
pedal travel is longer. The stopping
distance is increased.
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 63).
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 (
page 253).
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
further 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 434).
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USA only:
;
Canada only:
3
Reduced
Brake Effect
Service
RequiredThe electro-hydraulic brake system
is in emergency operation mode.
Considerably greater brake pedal
force is required and the brake
pedal travel is longer. The stopping
distance is increased.Stop the vehicle in a safe location or as soon
as it is safe to do so.
Apply the parking brake (page 63).
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 (
page 253).
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
further 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 434).
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380 Practical hints
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2 Brake WearThe brake pads have reached their
wear limit.Have the brake pads replaced as soon as pos-
sible.
Warning!G
Have brake pad replacement and other work
on the electro-hydraulic brake system
carried out by qualified technicians only.
Contact an authorized Mercedes-Benz
Center for further information.
The electro-hydraulic brake system must be
deactivated prior to working on the system.
High pressure is intermittently built up in the
system as part of its automatic self-test.
In addition, the system is automatically
activated when the vehicle is unlocked by
remote control, when the driver or passen-
ger door is opened, when the SmartKey in
the starter switch is turned to position1 or
the KEYLESS-GO* start/stop button is
pressed once, when the brake pedal
is depressed or when the parking brake is
released. Failure to deactivate the system
prior to maintenance will cause brake pis-
tons to extend and brake fluid to leak, which
may result in injuries (contusions and acid
burns). Extended brake pistons may also
cause injury.!Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.