2008 BMW 335I CONVERTIBLE brakes

Driving
60
Starting the engine
Do not run the engine in closed rooms,
otherwise the inhalation of toxic exhaust
gases can cause unconsciousness and death.
The exhaust gases contain carbon monoxide,
an odorless and colorless, but highly toxic gas.
Never leave an unattended vehicle with the
engine running, otherwise such a vehicle repre-
sents a potential safety hazard.
Before leaving the car with the engine running,
place the transmission in idle or move the
selector lever to position P and forcefully apply
the parking brake to prevent the car from mov-
ing.<
Avoid frequent starting in quick succes-
sion as well as repeated start attempts in
which the engine does not start. Otherwise, the
fuel is not burned or incompletely burned and
there is a danger of overheating and damaging
the catalytic converter.<
Do not wait for the engine to warm up while the
vehicle remains stationary. Start driving right
away, but at moderate engine speeds.
Manual transmission
Remote control in the ignition lock or, with con-
venient access, inside the vehicle, refer to
page36.
1.Depress the brake.
2.Depress the clutch and shift to idle position.
3.Press the start/stop button.
The starter operates automatically for a certain
time, and stops automatically as soon as the
engine has started.
Automatic transmission
Remote control in the ignition lock or, with con-
venient access, inside the vehicle, refer to
page36.
1.Depress the brake.
2.Move the selector lever to position P.
3.Press the start/stop button.
The starter operates automatically for a certain
time, and stops automatically as soon as the
engine has started.
Switching off the engine
Always take the remote control with you
when you leave the vehicle.
When parking, apply the parking brake force-
fully, otherwise the vehicle could begin to roll.<
Manual transmission
1.With the car at a standstill, press the start/
stop button.
2.Shift into first gear or reverse.
3.Forcefully apply the parking brake.
4.Removing the remote control from the igni-
tion lock, refer to page59.
Automatic transmission
1.With the car at a standstill, move the selec-
tor lever to position P.
2.Press the start/stop button.
3.Forcefully apply the parking brake.
4.Removing the remote control from the igni-
tion lock, refer to page59.
Parking brake
The parking brake is primarily intended to pre-
vent the vehicle from rolling while parked; it
brakes the rear wheels.

Driving
66
Cruise control*
The concept
Cruise control is available for use at speeds of
approx. 20 mph or 30 km/h. The car then stores
and maintains the speed that you specify using
the lever on the steering column. In order to
maintain the specified speed, the system
brakes the vehicle when the engine braking
effect is insufficient on downhill gradients.
Do not use cruise control when driving at
constant speed is prevented by adverse
conditions, e.g. winding roads, dense traffic or
poor road conditions due to, e.g., snow, rain, ice
or loose surfaces. Otherwise you could lose
control of the vehicle and cause an accident as a
result.<
Manual transmission
You can shift gears while cruise control is acti-
vated. An indicator lamp notifies you that you
should shift gears when you drive for an
extended period at very high or very low engine
speeds, or the system is deactivated.
One lever for all functions
1Storing and maintaining speed or accelerat-
ing
2Storing and maintaining speed or deceler-
ating
3Deactivating cruise control
4Resuming a speed stored beforehand
Maintaining current speed
Tap the lever, arrow 1, or pull it briefly, arrow 2.
The car's current speed is stored and main-tained. It is displayed on the speedometer and
briefly in the instrument cluster.
On uphill gradients, it may prove impossible to
maintain the set speed if current engine power
output is insufficient. If the engine braking
effect is insufficient on downhill slopes, the sys-
tem will brake the vehicle slightly.
Increasing desired speed
Repeatedly press the lever to the resistance
point or beyond, arrow1, until the desired
speed is reached.
>Each time the lever is pressed to the resis-
tance point, the desired speed is increased
by approx. 1 mph or 1 km/h.
>Each time the lever is pressed beyond the
resistance point, the desired speed is
increased by up to 5 mph or 10 km/h.
The system stores and maintains the speed.
Accelerating using the lever
Accelerating slightly:
Press the lever to the resistance point, arrow 1,
until the desired speed is reached.
Accelerating significantly:
Press the lever beyond the resistance point,
arrow 1, until the desired speed is reached.
The vehicle accelerates without pressure on
the accelerator pedal. The system stores and
maintains the speed.
Decreasing speed
Repeatedly pull the lever to the resistance point
or beyond, arrow 2, until the desired speed is
displayed.
>Each time the lever is pulled to the resis-
tance point, the desired speed is decreased
by approx. 1 mph or 1 km/h.
>Each time the lever is pulled beyond the
resistance point, the desired speed is
reduced by up to 5 mph or 10 km/h until the
minimum speed of 20 mph or 30 km/h is
achieved.
The system stores and maintains the speed.

Driving
68 the distance to be maintained from the vehicle
in front in four stages. For safety reasons, the
distance is speed-dependent. Based on your
selected distance setting, the system automat-
ically decreases the throttle setting and lightly
applies the brakes if necessary. The vehicle
brake lamps will automatically illuminate to sig-
nal a following driver to take action. In addition,
it may be necessary for the vehicle or the driver
to downshift, depending on the kind of trans-
mission your vehicle is equipped with, to main-
tain the distance setting selected. If the vehicle
ahead speeds up or when the lane ahead
becomes clear, your vehicle will accelerate to
the speed you have selected by increasing the
throttle setting and shifting gears automatically
or by the driver as needed. Your selected speed
will be held when driving downhill, too.
Since this active cruise control system is a new
technology and operates differently from con-
ventional cruise control systems which you may
be accustomed to, you are strongly urged to
read all of the pages relating to this system
before use. Pay special attention to the System
limitations section beginning on page71.
Braking sensation
>If you step on the brake pedal while the sys-
tem is braking, pedal sensation will be
slightly different from the usual.
>Possible noises during automatic braking
are normal.
Manual transmission
You can shift gears while cruise control is acti-
vated. An indicator lamp notifies you that you
should shift gears when you drive for an
extended period at very high or very low engine
speeds, or the system is deactivated.
Range of applications
The minimum desired speed is 20 mph or
30 km/h, the maximum desired speed is
110mph or 180km/h.
As with conventional cruise control sys-
tems, active cruise control in no way
diminishes or substitutes for the driver’s own personal responsibility, alertness and aware-
ness in adjusting speed, braking or otherwise
controlling the vehicle. The driver should
decide when to use the system on the basis of
road, traffic, visibility, and weather conditions.
Active cruise control is intended for use on
highway-type roadways where traffic is moving
relatively smoothly. Do not use this system in
city driving; heavy traffic such as during rush
hour; on curvy, winding roads, slippery roads or
roads with sharp curves such as highway off-
ramps; during inclement weather such as snow,
strong rain or fog; or when entering inter-
changes, service/parking areas or toll booths.
It is also important to regulate your vehicle's
speed and distance setting within applicable
legal limits. Always be ready to take action or
apply the brakes if necessary, especially when
the system is actively following a vehicle in front
of you. Otherwise driving situations could result
that pose the risk of accidents.<
One lever for all functions
1Store and increase desired speed
2Store and decrease desired speed
3Deactivate system, refer to page70
4Resume stored desired speed and dis-
tance, refer to page70
5Select distance to vehicle driving ahead,
refer to page69
Storing current speed
Briefly press the lever, arrow 1, or briefly pull it,
arrow 2, at a driving speed of more than approx.
20 mph or 30 km/h.

Controls
71Reference
At a glance
Driving tips
Communications
Navigation
Entertainment
Mobility
are currently not met. Calling up Check Control
messages, refer to page84.<
Warning lamps
The indicator2 flashes in red; a
signal sounds.
The system indicates that you
must brake and/or maneuver the
vehicle yourself. Active cruise con-
trol cannot automatically restore the distance to
the vehicle ahead.
This indicator does not release you from your
responsibility to adapt your desired speed and
driving style to prevailing driving conditions.
The indicator 2 flashes in yellow.
The prerequisites for operating
active cruise control are not met,
e.g. as a result of ABS or DSC
interventions. Active cruise control
is deactivated. You can reactivate the system, if
desired, by tapping or pulling the lever when
road and traffic conditions permit. It is not pos-
sible to resume a stored speed.
Radar sensor
The sensor's ability to detect vehicles ahead
may be restricted as a result of heavy rain, dirt,
snow or ice. If necessary, clean the radar sensor
located in the front bumper, see arrow. Be sure
to use particular care when removing any layers
of snow or ice from the sensor.
When the radar sensor is not properly posi-
tioned, active cruise control cannot be activated
at all.
Malfunction
The warning lamp comes on when
the system has failed. A message
appears on the Control Display. You
can find more information starting on page83.
System limitations
Always remember that the range and abil-
ity of the system does have physical limi-
tations. It will not apply the brakes or decelerate
your vehicle when there is a slow-moving vehi-
cle, stopped vehicle or stationary object ahead
of you, as for example, at a traffic light or a
parked vehicle. Also, the system does not react
to oncoming traffic, pedestrians or other types
of potential traffic such as a rider on horseback.
It is also possible that the system may not detect smaller moving objects such as motor-
cycles or bicycles. Be especially alert when
encountering any of these situations as the sys-
tem will neither automatically brake, nor provide
a warning to you. Also, be aware that every
decrease in the distance setting allows your
vehicle to come closer to a vehicle in front of
you and requires a heightened amount of alert-
ness.<

Driving
72 Active cruise control is not and must not
be used as a collision avoidance/warning
system.<
If while your vehicle is actively following a vehi-
cle in front of you and the vehicle ahead speeds
up or the lane ahead becomes clear, then your
vehicle will accelerate to the speed you have
selected. Be aware that changing to a clear,
unobstructed lane will also result in your vehicle
accelerating.
Be certain to deactivate the system when
you pull into an exit lane for a highway off-
ramp.<
Also, vehicles traveling in a staggered manner
on a highway may cause a delay in the system's
reaction to a vehicle in front of you or may cause
the system to react to a vehicle actually in the
lane next to you. Always be ready to take action
or apply the brakes if necessary.
While active cruise control is capable of
braking your vehicle automatically when
you approach a slower vehicle ahead, it is
important to be aware that the ability of the sys-
tem to apply the brakes is also limited, e.g.
when you reduce your desired speed sharply.
The system cannot stop your vehicle. It uses
only a portion of braking system capacity and
does not utilize the full capacity of the vehicle
braking system. Therefore, the system cannot
decrease your speed for large differences in
speed between your vehicle and the vehicle
ahead. Examples: when you approach a vehicle
traveling at a much lower speed than your own
speed such as approaching a toll booth or when
a much slower vehicle cuts in front of you at
close range.<
Active cruise control can only decelerate the
vehicle to approx. 20 mph or 30 km/h.
Swerving vehicles
When a vehicle moves from an adjacent lane
into your lane, active cruise control will not rec-
ognize this vehicle until it is fully in your lane
ahead of your vehicle.
When a vehicle ahead suddenly swerves
into your lane, the system may not be able
to maintain the selected distance automatically.
This also applies to great differences in speed
between you and vehicles ahead, e.g. when
quickly approaching a truck. There is a risk of
collision. Once the system has established that
a vehicle is indeed in front of you, it will indicate
that you must brake and/or maneuver the vehi-
cle yourself. Take action yourself, otherwise
there is a risk of an accident.<
Behavior in curves
Because of the limited range of the system, it is
possible that in curves or on the peaks and val-
leys of hilly roads, a vehicle ahead may be rec-
ognized late, or not at all. Therefore, it is up to
the driver to select a speed that is prudent in
view of the curves and terrain of the roadway.

Controls
89Reference
At a glance
Driving tips
Communications
Navigation
Entertainment
Mobility
until "PDC" is selected and press the con-
troller.
6.Select "PDC display on" and press the con-
troller.
The PDC screen is activated.
The display is shown on the Control Display as
soon as PDC is activated.
System limitations
Even with PDC, final responsibility for
estimating the distance between the
vehicle and any obstructions always remains
with the driver. Even when sensors are pro-
vided, there is a blind spot in which objects can
no longer be detected. The system is also sub-
ject to the physical limits that apply to all forms
of ultrasonic measurement, such as those
encountered with trailer towbars and hitches,
thin or wedge-shaped objects, etc. Low objects
that have already been displayed, e. g. curbs,
can disappear again from the detection area of
the sensors before or after a continuous tone
sounds. Higher, protruding objects, e.g. ledges,
cannot be detected. Therefore, always drive
cautiously, otherwise there is a risk of personal
injury or property damage.
Loud sound sources outside or inside the car
can drown out the PDC signal.<
Driving stability control
systems
Your BMW has a number of systems that help
to maintain the vehicle's stability even in
adverse driving conditions.
ABS Antilock Brake System
ABS prevents locking of the wheels during
braking. Safe steering response is maintained
even during full braking. Active safety is thus
increased.
The ABS is operational every time you start the
engine. Braking safely, refer to page126.
Electronic brake-force distribution
The system controls the brake pressure in the
rear wheels to ensure stable braking behavior.
DBC Dynamic Brake Control
When you apply the brakes rapidly, this system
automatically produces the maximum braking
force boost and thus helps to achieve the short-
est possible braking distance during full brak-
ing. This system exploits all of the benefits pro-
vided by ABS.
Do not reduce the pressure on the brake for the
duration of the full braking application.
DSC Dynamic Stability Control
DSC prevents the driving wheels from losing
traction when you pull away from rest or accel-
erate. The system also recognizes unstable
driving conditions, for example if the rear of the
car is about to swerve or if momentum is acting
at an angle past the front wheels. In these
cases, DSC helps the vehicle maintain a safe
course within physical limits by reducing engine
output and through braking actions at the indi-
vidual wheels.
The laws of physics cannot be repealed,
even with DSC. An appropriate driving
style always remains the responsibility of the
driver. Therefore, do not reduce the additional
safety margin again by taking risks, as this could
result in an accident.<

Things to remember when driving
124
Things to remember when driving
Break-in period
Moving parts need breaking-in time to adjust to
each other. Please follow the instructions below
in order to achieve the optimal service life and
economy of operation for your vehicle.
Engine and differential
Always obey all official speed limits.
Up to 1,200 miles/2,000 km
Drive at varying engine and road speeds, but do
not exceed an engine speed of 4500 rpm or a
road speed of 100 mph/160 km/h.
Avoid full-throttle operation and use of the
transmission's kick-down mode.
After driving 1,200 miles/2,000 km
Engine and vehicle speeds can be gradually
increased.
Tires
Due to technical factors associated with their
manufacture, tires do not achieve their full trac-
tion potential until after an initial break-in
period. Therefore, drive cautiously during the
first 200 miles/300 km.
Brake system
Brakes require an initial break-in period of
approx. 300 miles/500 km to achieve optimized
contact and wear patterns between brake pads
and rotors. Drive cautiously during this break-in
period.
Clutch
The function of the clutch reaches its optimal
level only after a distance driven of approx.
300 miles/500 km. During this break-in period,
engage the clutch gently.
Following part replacement
The same break-in procedures should be
observed if any of the components mentioned
above have to be renewed in the course of the
vehicle's operating life.
Saving fuel
The fuel consumption of your vehicle depends
on several factors. You can lower fuel consump-
tion and the environmental impact by taking
certain measures, adjusting your driving style
and having the vehicle serviced regularly.
Remove any unneeded cargo
Additional weight increases fuel consumption.
Remove any mounted parts after you
have finished using them
Remove unneeded additional mirrors, the roof
rack and the rear luggage rack after use.
Mounted parts affect the vehicle's aerodynam-
ics and increase fuel consumption.
Close the windows and glass roof
An open glass roof or window causes higher air
resistance and thus increases fuel consump-
tion.
Check tire inflation pressure regularly
Check the tire inflation pressure at least twice a
month and before embarking on a long journey,
and correct it if necessary.
Low tire inflation pressure causes higher rolling
resistance and thus increases fuel consumption
and tire wear.
Set off immediately
Do not let the engine warm up while the car is
still standing, but set off immediately at moder-
ate engine speed. This is the fastest way for the
cold engine to reach its operating temperature.

Things to remember when driving
126 The risk of hydroplaning increases with declin-
ing tread depth on the tires, refer also to Mini-
mum tread depth on page221.
Driving through water
Drive through water on the road only if it is
not deeper than 1 ft/30 cm, and then only
at walking speed at the most. Otherwise, the
vehicle's engine, the electrical systems and the
transmission may be damaged.<
Use the parking brake on inclines
On inclines, do not hold the vehicle for a
lengthy period using the clutch; use the
parking brake instead. Otherwise greater clutch
wear will result.<
For more information about the drive-off assis-
tant, refer to page91.
Braking safely
Your BMW is equipped with ABS as a standard
feature. Applying the brakes fully is the most
effective way of braking in situations in which
this is necessary. Since the vehicle maintains
steering responsiveness, you can still avoid
possible obstacles with a minimum of steering
effort.
Pulsation of the brake pedal, combined with
sounds from the hydraulic circuits, indicate that
ABS is in its active mode.
Driving in wet conditions
When roads are wet or there is heavy rain,
briefly exert gentle pressure on the brake pedal
every few miles. Monitor traffic conditions to
ensure that this maneuver does not endanger
other road users. The heat generated in this
process helps dry the pads and rotors to ensure
that full braking efficiency will then be available
when you need it.
Hills
To prevent overheating and the resulting
reduced efficiency of the brake system,
drive long or steep downhill gradients in the
gear in which the least braking is required. Even
light but consistent brake pressure can lead to high temperatures, brake wear and possibly
even brake failure.<
You can increase the engine's braking effect by
shifting down, all the way to first gear if neces-
sary. This strategy helps you avoid placing
excessive loads on the brake system. Down-
shifting in manual mode of the automatic trans-
mission, refer to page62.
Never drive with the clutch held down,
with the transmission in idle or with the
engine switched off; otherwise, engine braking
action will not be present or there will be no
power assistance to the brakes or steering.
Never allow floor mats, carpets or any other
objects to protrude into the area around the
pedals, otherwise pedal function could be
impaired.<
Corrosion on brake rotors
When the vehicle is driven only occasionally,
during extended periods when the vehicle is not
used at all, and in operating conditions where
brake applications are less frequent, there is an
increased tendency for corrosion to form on
rotors, while contaminants accumulate on the
brake pads. This occurs because the minimum
pressure which must be exerted by the pads
during brake applications to clean the rotors is
not reached.
Should corrosion form on the brake rotors, the
brakes will tend to respond with a pulsating
effect that even extended application will fail to
cure.
When the vehicle is parked
Condensation forms while the automatic cli-
mate control is in operation, and then exits
under the vehicle. Traces of condensed water
under the vehicle are therefore normal.
Before driving into a car wash
For general information about taking care of
your BMW, refer to the Caring for your vehicle
brochure.