94n
PDC
*
Dynamic Stability Control (DSC)
The PDC system does not remove
the driver's personal responsibility
for evaluating the distance between the
vehicle and any obstacles. Even when
sensors are involved, there is a blind
spot in which objects cannot be
detected. This applies especially in
those cases where the system
approaches the physical constraints of
ultrasonic measurement, as occurs with
tow bars and trailer couplings, and in
the vicinity of thin and painted objects.
Certain sources of sound, such as a
loud radio, could drown out the PDC
signal tone.<
Keep the sensors clean and free
of ice or snow in order to ensure
that they continue to operate effectively.
Do not apply high pressure spray to the
sensors for a prolonged period of time.
Maintain an adequate distance of more
than 4 in (10 cm).<
The concept DSC maintains vehicle stability, even in
critical driving situations.
The system optimizes vehicle stability
during acceleration and when starting
from a full stop, as well as optimizing
traction. In addition, it recognizes
unstable vehicle conditions, such as
understeering or oversteering, and, as
far as is possible within the laws of
physics, keeps the car on a steady
course by adapting the RPMs and
brake applications to the individual
wheels.
The system starts up automatically
each time you start the engine.
Indicator lamp
The indicator lamp in the instru-
ment cluster goes out shortly
after you switch on the ignition.
Refer to page 24.
Indicator lamp flashes:
The system is active and governs drive
and braking force.
If the indicator lamp fails to go out after
the engine is started, or comes on
during normal driving and stays on:
The system is either defective or was
switched off with the button: the stabi-
lizing applications described to the left
are no longer available. The vehicle will
remain completely operational,
however, without DSC.
Consult your BMW center to have the
system repaired.
IndexDataTechnologyRepairsCar careControlsOverview
95n
Dynamic Stability Control (DSC)
Hill Descent Control
To deactivate the system Press the button (arrow); the indicator
lamp comes on and stays on.
Traction intervention remains active;
that is, braking intervention will
continue. Refer also to "Four-wheel
drive" on page 197.
In the following exceptional circum-
stances, it may be effective to deacti-
vate the DSC for a short period:
>When rocking the vehicle or starting
off in deep snow or on loose
surfaces.
>On sandy road surfaces.
>On poor surfaces with deep ruts.
>If the wheels "churn" on muddy
surfaces.
>When driving with snow chains. 530us048
As a result of the traction interven-
tion, the brakes may be subjected
to additional loads when the system is
deactivated. For this reason, it is
possible that the braking intervention
will be disabled automatically for a brief
period in order to limit brake tempera-
ture.
To maintain vehicle stability, always
drive with the system switched on when
possible.<
To reactivate the systemPress the button again; the indicator
lamp goes out.
The laws of physics cannot be
repealed, even with DSC. An
appropriate driving style always
remains the responsibility of the driver.
We therefore urge you to avoid using
the additional safety margin of the
system as an excuse for taking risks.
Do not make any modifications to the
DSC system. Service procedures on
the system are to be performed by
authorized technicians only.<
For additional details concerning DSC,
please refer to the chapter describing
"Advanced technology" on page 197.
The concept HDC is a system for driving downhill in
steep terrain. This system reduces
vehicle speed on steep downhill gradi-
ents, thus allowing you to maintain
control of your BMW under these
conditions.
The vehicle moves at slightly more than
walking speed without active interven-
tion from the driver.
You can activate HDC below approx.
20 mph (30 km/h). When driving down
steep hills, the vehicle reduces speed
automatically down to slightly more
than walking speed (approx. 5 mph/
8 km/h) and then maintains this speed
at a constant.
By applications of the brakes or accel-
erator, you can alter this speed in the
range of approx. 3 mph (5 km/h) to
approx. 20 mph (30 km/h).
HDC is deactivated automatically if you
exceed approx. 35 mph (60 km/h).
134n
Break-in proceduresTo ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you
observe the following suggestions: Engine and axle drive Up to 1,200 miles (2,000 km):
Drive at varying engine speeds and
road speeds, but do not exceed
4,500 rpm and the following road
speeds during this initial period:
BMW X5 3.0i: 100 mph (160 km/h)
BMW X5 4.4i: 106 mph (170 km/h)
Obey your local and state maximum
speed limits.
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
Once you have driven 1,200 miles
(2,000 km), engine and vehicle speeds
can gradually be increased.
You should also comply with these
break-in procedures if the engine or
one of the axle drives is replaced later
in the course of the vehicle service life.
TiresDue to technical factors associated
with their manufacture, tires do not
achieve their full traction potential until
an initial break-in period has elapsed.
For this reason, drive with extra care
during the initial 200 miles (300 km).
Obey your local and state maximum
speed limits.
When the vehicle is operated on
wet or slushy roads, a wedge of
water may form between the tire and
the road surface. This phenomenon is
referred to as aquaplaning, or hydro-
planing, and can lead to partial or
complete loss of traction, vehicle
control and braking effectiveness.
Reduce your speed on wet roads.<
Brake systemApprox. 300 miles (500 km) must
elapse before the brake pads and discs
achieve the optimal pad-surface and
wear patterns required for trouble-free
operation and long service life later on.
To break in the separate parking brake
drums, apply the parking brake lightly
when coasting to a standstill (at a traffic
signal, for instance), provided that
traffic conditions allow you to do so.
To avoid corrosion, repeat this proce-
dure from time to time.
The brake lamps do not light up
when the parking brake is applied.
Vacuum for the brake system servo unit
on your BMW is available only when the
engine is running. When you move the
vehicle with the engine shut off – when
towing, for instance – substantially
higher levels of pedal force will be
required to brake the vehicle.<
IndexDataTechnologyRepairsCar careControlsOverview
137n
Catalytic converter Antilock Brake System (ABS)
Be sure to comply with the
instructions above to prevent
unburned fuel from reaching the cata-
lytic converter. Otherwise, the catalytic
converter could respond by over-
heating, leading to serious damage.
Extreme temperatures occur at the
catalytic converter on this and every
catalyst-equipped vehicle. Heat shields
are installed adjacent to some sections
of the exhaust system. Never remove
these shields; do not apply under-
coating to their surfaces. When driving,
standing at idle, and parking the
vehicle, take care to avoid contact
between the exhaust system and flam-
mable materials (grass, hay, leaves,
etc.). Such contact could lead to a fire,
resulting in serious personal injury and
property damage.<
The concept ABS enhances active safety by helping
to prevent the wheels from locking
under braking. This is because: locked
wheels are dangerous. When the front
wheels slide, the driver loses steering
control over the vehicle. Traction loss at
the rear wheels can cause the rear end
to break into an uncontrolled skid.
With ABS, you will achieve the shortest-
possible braking distances under all
given conditions (braking while driving
straight ahead or in curves, different
road surfaces).
ABS is designed to meet two essential
requirements during every brake appli-
cation:
>To help provide vehicle stability.
>To help retain steering and maneu-
vering capability on all types of road
surfaces (asphalt, cement, dirt, wet
surfaces, snow and ice).
Braking with ABS The system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). The ABS is inactive
again whenever the vehicle's speed
drops back below approx. 4 mph
(6 km/h).
To shorten the braking distance — espe-
cially on steep, poor road surfaces when
driving slowly straight ahead — the
system allows one or both front wheels
to lock for a short time. Nevertheless,
the vehicle still retains steering
response since this "poor road logic" is
deactivated again automatically as you
steer.
If you are in a situation that requires full
braking, you will exploit the full benefits
of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering
responsiveness, you can avoid possible
obstacles with a minimum of steering
effort, despite the full brake application.
The ABS system's closed-loop control
circuit cycles in fractions of a second.
A pulsation at the brake pedal, together
with the sounds associated with the
hydraulic controls, tells you that the
brake system is within its maximum
limit range and reminds you that you
138n
Antilock Brake System (ABS)should adapt road speed to the road
conditions.
On road surfaces that have a loose
surface layer on a firm base with good
traction (on gravel, deep sand or snow,
for example), braking distances may be
longer than with locked wheels.This is
also true if snow chains are mounted.
However, ABS continues to provide
enhanced vehicle stability and steering
response under these conditions. Information for your safety Not even ABS can suspend the laws of
physics. ABS alone cannot prevent
accidents when the brakes are applied
without an adequate safety distance
between vehicles, if the vehicle is
driven with excessive speed, or if aqua-
planing occurs. Responsibility for these
types of situations remains in the hands
(and at the feet) of the driver. You
should never allow the added safety of
ABS to lull you into a false sense of
security, or mislead you into taking
increased risks that could affect your
own safety and that of others.
Do not make any modifications to
the ABS system.
Service procedures on ABS are to be
performed by authorized technicians
only.<
Cornering Brake Control (CBC) CBC is an advanced engineering
design of the ABS. When braking
during cornering with high lateral accel-
eration, or when braking during a lane
change, vehicle stability is further
improved and the steering response is
enhanced. Electronic Brake Force
Distribution (EBV) EBV governs brake application pres-
sure at the rear wheels to achieve
stable brake response.
If the EBV fails (refer to the next
page), avoid full or "panic" brake
applications. Full or panic brake appli-
cations can result in overbraking at the
rear axle, and braking stability is no
longer ensured.<
Dynamic Brake Control (DBC)
If you apply the brakes rapidly, this
system automatically produces the
maximum braking force boost and thus
helps to achieve the shortest possible
braking distance during "panic stops."
All of the benefits of the ABS system
are exploited under these circum-
stances.
Do not reduce the pressure on the
brake pedal for the duration of the
brake application. When the brake
pedal is released, the DBC is deacti-
vated.
In the event of a malfunction,
the yellow warning lamp comes
on. Have the system checked
and repaired at your BMW
center as soon as possible.
Refer to the "Information for your
safety" covering the ABS system.
This information also applies in general
for DBC.<
142n
Winter operation Rubber seals and components In order to prevent the weather-strip-
ping from freezing, apply BMW rubber
treatment or silicone spray to the seals
on the doors, hood and liftgate/tailgate.
A full range of car care products is
available from your BMW center.< Snow chains Mount BMW snow chains
* only on tire
size 235/65 R 17. Always mount chains
in pairs and on the rear wheels only.
Read and comply with the chain manu-
facturer's safety precautions. Do not
exceed a maximum speed of 30 mph
(50 km/h).
Starting offWhen starting in deep snow or
"rocking" the vehicle free, it may be
advisable to deactivate the DSC system
briefly. Refer to page 94.
Driving on low-traction road
surfaces Use smooth, gentle pressure to control
the accelerator pedal. Avoid excessive
engine speeds and shift to the next
higher gear at an early point. Also shift
to the next lower gear at an early point
when approaching grades or slopes.
Maintain an adequate distance
between yourself and the car ahead. BrakingWinter road conditions substantially
reduce the amount of traction available
between the tires and the road surface.
The resulting increases in braking
distance are considerable and should
be kept in mind at all times.
ABS is intended to prevent the wheels
from locking during brake applications,
thus helping to maintain vehicle stability
and steering response. If the ABS does not respond in a critical
braking situation and the wheels lock:
Reduce the pressure on the brake
pedal until the wheels just start to roll
again while still maintaining enough
force to continue braking. Following
that, increase pedal pressure again.
Reduce the pressure as the wheels
lock, then reapply pressure. Repeat this
braking sequence.
This type of staggered braking will
reduce the braking distance, and the
vehicle still remains responsive to
steering.
You can then attempt to steer around
hazards after you have reduced pres-
sure on the brake pedal.
Do not shift down on slick road
surfaces if you want to decelerate.
Doing so could cause the wheels to
lose traction and skid, thus resulting in
the loss of vehicle control.<
Depress the clutch during hard
braking on road surfaces that
provide only poor or uneven traction.<
146n
Tire replacement To maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer. BMW tests and approves
wheel/tire combinations. Refer to
page 148. DOT Quality GradesTreadwear
Traction AA A B C
Temperature A B C
All passenger car tires must
conform to Federal Safety
Requirements in addition to these
grades.< TreadwearThe treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would
wear one and one-half (1g) times as
well on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.
TractionThe traction grades, from highest to
lowest, are AA, A, B, and C.
Those grades represent the tire's ability
to stop on wet pavement as measured
under controlled conditions on speci-
fied government test surfaces of
asphalt and concrete. A tire marked C
may have poor traction performance.
The traction grade assigned to
this tire is based on straight-
ahead braking traction tests, and does
not include acceleration, cornering,
aquaplaning, or peak traction charac-
teristics.< TemperatureThe temperature grades are A (the
highest), B, and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause
the material of the tire to degenerate
and reduce tire life, and excessive
temperature can lead to a sudden flat
tire. The grade C corresponds to a level
of performance which all passenger car
tires must meet under the Federal
Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels
of performance on the laboratory test
wheel than the minimum required by
law.
The temperature grade for this tire
is established for a tire that is
properly inflated and not overloaded.
Excessive speed, underinflation, or
excessive loading, either separately or
in combination, can cause heat buildup
and possible a flat tire.< Uniform Tire Quality Grading Quality grades can be found where
applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA
Temperature A
Do not use retreaded tires, since
driving safety may be impaired by
their use. This is due to the possible
variations in casing structures and, in
some cases, to their extreme age,
which can lead to a decrease in their
durability.<
IndexDataTechnologyRepairsCar careControlsOverview
149n
Special features of winter tires Snow chains
*
Choosing the right tireBMW recommends winter tires (M+S
radial tires) for operation under inclem-
ent winter driving conditions. While
so-called all-season tires (M+S desig-
nation) provide better winter traction
than summer tires with the load ratings
H, V, W, Y and ZR, they generally do
not achieve the performance of winter
tires.
In the interests of safe tracking and
steering response, install radial tires
made by the same manufacturer and
with the same tread configuration on all
four wheels if you elect to mount winter
tires.
Do not exceed specified
maximum speeds
Never exceed the maximum speed
for which the tires are rated.
Unprofessional attempts by laymen to
service tires can lead to damage and
accidents.
Have this work performed by skilled
professionals only. Your BMW center
will be glad to assist you with both their
expertise and the proper equipment for
your vehicle.<
Tire condition, tire pressureWinter tires display a perceptible loss in
their ability to cope with winter driving
conditions once the tread wears to
below 0.16 in (4 mm), and should thus
be replaced.
Comply with the specified tire inflation
pressures — and be sure to have the
wheel and tire assemblies balanced
every time you change the tires.
The use of narrow-link BMW snow
chains is approved only in pairs on the
rear wheels and only with tire size
235/65 R 17. Comply with all manufac-
turer's safety precautions when
mounting the chains.