2009 MERCEDES-BENZ SLR parking brake

290 OperationTires and wheelsThoroughly clean the mounting face of
wheels and brake disks, i.e. the inner side
of the wheels/tires, during each rotation.
Check for and ensure proper tire inflation
pressure.
For information on wheel change, see the
“Practical hints” section (
page 365).
Anti-theft wheel nuts
Your vehicle is equipped with anti-theft
wheel nuts that prevent the theft of your
vehicle’s wheels.
1Anti-theft wheel nut
2Wheel nut key
Removing anti-theft wheel nuts

Unscrew anti-theft wheel nut1 using
wheel nut key2.

Replace anti-theft wheel nut1 with
one of the regular wheel bolts.

Fasten the wheel bolt and tighten it
with a torque wrench to a tightening
torque of 95 lb-ft (130 Nm).
Warning!
G
Have the tightening torque checked after
changing a wheel. Wheels could become
loose if not tightened with a torque of
95 lb-ft (130 Nm).
Only use Genuine Mercedes-Benz wheel
bolts specified for your vehicle’s rims.
Warning!
G
Pull the parking brake lever up as many
notches as possible and move the gear se-
lector lever to park positionP, before loos-
ening the wheel bolts. Otherwise the vehicle
may move and cause an accident and/or
serious personal injury. !
Do not use air tools, such as an impact
wrench, when installing or removing the
anti-theft wheel nuts. An impact wrench can
damage the anti-theft wheel nuts and the wheel
nut key, or cause them to malfunction.
!
Store wheel bolts and anti-theft wheel nuts
not currently in use in a safe place to avoid
damage to the threads.

307 Practical hints
What to do if ...
Problem
Possible cause/consequence
Suggested solutions
3
(Canada only)
;
(USA only)
The red brake warning lamp
comes on while driving and
you hear a warning sound.
You are driving with the parking brake set.

Release the parking brake (
page 49).
3
(Canada only)
;
(USA only)
The red brake warning lamp
comes on while the engine is
running and you hear a
warning sound.
Risk of accident!

There is a malfunction in the
electro-hydraulic brake system.


There is insufficient brake fluid in the
reservoir.

Carefully stop the vehicle in a safe location
or as soon as it is safe to do so and contact
an authorized Mercedes-Benz Center. Do
not add brake fluid! This will not solve the
problem.

Read and observe messages in the
multifunction display (
page 319).
Warning!
G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Do not add
brake fluid before checking the brake
system.
Overfilling the brake fluid reservoir can re-
sult 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.

308 Practical hintsWhat to do if ...Problem
Possible cause/consequence
Suggested solutions
ú
(USA only)
±
(Canada only)
The yellow engine malfunc-
tion indicator lamp comes on
while the engine is running.
There is a malfunction in:

The fuel injection system


The ignition system


The emission control system


Systems which effect emissions
Such malfunctions may result in excessive
emissions values and may switch the
engine to its limp-home (emergency
operation) mode.

Have the vehicle checked as soon as possi-
ble by an authorized Mercedes-Benz Center.
An on-board diagnostic connector is used by
the service station to link the vehicle to the
shop diagnostics system. It allows the accu-
rate identification 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.
i
Some states may by law require you to visit
a workshop as soon as the engine malfunction
indicator lamp comes on. Check local require-
ments.

324 Practical hintsWhat to do if ...Left display
Right display
Possible cause/consequence
Possible solution
Front Passeng.
Airbag
Enabled
See Oper. Manual
The 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)

326 Practical hintsWhat to do if ...Left display
Right display
Possible cause/consequence
Possible solution
Front Passeng.
Airbag
Disabled
See Oper. Manual
The 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.
(Continued on next page)

334 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
T
Reduced
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 373).

336 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
;
(USA only)
3
(Canada only)
Reduced
Brake Effect
Service
Required
The electro-hydraulic
brake system is in emer-
gency operation mode.
Considerably greater
brake pedal force is
required and the pedal
travel is longer. The stop-
ping distance is in-
creased. If necessary,
apply full pressure to the
brake pedal.

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.
Increased
Stopping Distance
Service
Required
Warning!
G
Driving while these messages are 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 373).

339 Practical hints
What to do if ...
Left display
Right display
Possible cause/
consequence
Possible solution
;
(USA only)
3
(Canada only)
Brake
Service
Required
There are malfunctions, but the
electro-hydraulic brake system
is operating normally.

Contact an authorized Mercedes-Benz Center
immediately.
Release
Parking Brake
You are driving with the parking
brake set.

Release the parking brake (
page 49).
2
Brake Wear
The brake pads have reached
their wear limit.

Have the brake pads replaced as soon as pos-
sible.
!
Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.
Excessive load on the brake system causes in-
creased wear of brake pads and brake disks. If
the brake pads have to be replaced multiple
times within one maintenance service interval,
the brake disks must be checked. Observe the
information given in the Maintenance Booklet
and contact an authorized Mercedes-Benz
Center.
Warning!
G
Have brake pad replacement and other work
on the electro-hydraulic brake system car-
ried out by qualified technicians only. Con-
tact your Mercedes-Benz Center for further
information. The electro-hydraulic brake
system must be deactivated prior to working
on the system. High pressure is intermit-
tently 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 passenger door is opened, when
the SmartKey in the starter switch is turned
to position1, when the brake pedal is
depressed or when the parking brake is
released.
Failure to deactivate the system prior to
maintenance will cause brake pistons to
extend and brake fluid to leak, which may
result in injuries (contusions and acid
burns), see “Electro-hydraulic brake sys-
tem” (
page 87).