85 Safety and Security
Driving safety systems
SBC brake system
The SBC brake system combines a hydrau-
lic brake circuit with electronically con-
trolled brake servo assistance. You have
increased braking safety and improved
braking comfort.Warning!
G
Never ignore a brake malfunction indicated
in the speedometer display, for example by
the;(USA only) or3(Canada only)
indicator lamp. Refer to the “Practical hints”
section (
page 326). Also read and ob-
serve the messages in the instrument clus-
ter multifunction display (
page 347).
Warning!
G
The SBC brake system requires electrical
power to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 326)
comes on and warning messages
(
page 347) appear in the multifunction
display while driving. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is in-
creased!
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate 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 408).
256 OperationDriving instructionsPower assistance
Brakes
Warning!
G
The brake system requires electrical energy
for operation.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. In such a case, the
red brake warning lamp (
page 326) and
warning messages (
page 335) in the in-
strument cluster come on while driving. To
brake, the driver must then apply signifi-
cantly greater brake pedal pressure and de-
press the pedal much further to obtain the
expected 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 malfunc-
tion in the SBC 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 408).
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
261 Operation
Driving instructions
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.Mercedes-Benz recommends M+S rated
radial-ply tires with a minimum tread depth
of approximately
1/6in (4 mm) on all four
wheels for the winter season to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance as compared with sum-
mer tires. Stopping distance, however, is
still considerably greater than when the
road is not covered with snow or ice. Exer-
cise appropriate caution.
Tire speed rating
Regardless of the tire speed rating, local
speed limits should be obeyed. Use pru-
dent driving speeds appropriate to prevail-
ing conditions.
Warning!
G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
!Avoid spinning of a drive wheel. This
may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Even when permitted by law, never operate
a vehicle at speeds greater than the maxi-
mum speed rating of the tires.
Exceeding the maximum speed for which
tires are rated can lead to sudden tire fail-
ure, causing loss of vehicle control and pos-
sibly resulting in an accident and/or
personal injury and possible death, for you
and for others.
290 OperationTires and wheelsChecking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least three hours or
driven less than one mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than three hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise, the tire will be
underinflated.Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:
Remove the cap from the valve on one
tire.
Firmly press a tire gauge onto the
valve.
Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
placard on the driver’s door B-pillar
(page 288). If necessary, add air to
achieve the recommended tire inflation
pressure.
Install the valve cap.
Repeat this procedure for each tire.
Checking tire inflation pressure
electronically
The tire inflation pressure monitor only
functions on wheels that are equipped with
the proper electronic sensors. It monitors
the tire inflation pressure, as selected by
the driver, in all four tires. A warning is
issued to alert you to a decrease in tire
inflation pressure in one or more of the
tires.
You can call up the tire inflation pressure
monitoring display using the control
system (
page 156).
iIf you have overfilled the tire, release
tire inflation pressure by pushing the
metal stem of the valve with e.g. a tip of
a pen. Then recheck the tire inflation
pressure with the tire gauge.
293 Operation
Tires and wheels
Reactivating the tire inflation pressure
monitor
The tire inflation pressure monitor must be
reactivated in the following situations:
If you have changed the tire inflation
pressure
If you have replaced the wheels or tires
If you have installed new wheels or
tires
Using the tire placard on the driver’s
door B-pillar or, if available, the inside
of the fuel filler flap, make sure the tire
inflation pressure of all four tires is cor-
rect.
Press button j or k repeatedly
until you see the current tire inflation
pressures for each tire appear in the
multifunction display or the following
message appears in the multifunction
display:Tire pressure
displayed only
after driving
a few minutes
Press the reset button on the instru-
ment cluster (
page 24).
The following message will appear in
the multifunction display:
Monitor current
tire pressure?
Press the æ button.
The following message will appear in
the multifunction display:Tire pres. monitor
reactivated
The tire inflation pressure monitor will
now monitor the tire inflation pressure
values of all four tires.
The following message will appear in
the multifunction display field:
Tire pressure
displayed only
after driving
a few minutesThis display appears until the individual
tire inflation pressure values are
matched with the tires. The individual
values are then displayed
(page 291).
iIf you are transporting a deflated tire in
the vehicle, do not activate the tire
inflation pressure monitor until
the deflated tire is no longer in the
vehicle
you have inflated the tire to the
correct tire inflation pressure
348 Practical hintsWhat to do if …Left display
Right display
Possible cause
Possible solution
USA only:;Canada only:3
Reduced
brake effect
Visit
workshop
The SBC brake system is in emer-
gency operation mode. Consider-
able brake pedal force is required
and the stopping distance is in-
creased.
Continue driving with added caution.
Adjust driving to be consistent with reduced
braking responsiveness.
Visit an authorized Mercedes-Benz Center im-
mediately. Adjust driving to be consistent
with reduced braking responsiveness.
Warning!
G
Driving while these messages are displayed
can result in an accident. Have your brake
system checked immediately.
If there is a malfunction in the SBC brake
system, we recommend that the vehicle be
transported with all wheels off the ground
using flatbed or appropriate 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 408).
If the SBC brake system enters its emergen-
cy 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!