ESP BMW Z4 2.5I 2003 User Guide

Technology for safety and driving convenience
52 For more information on the various
systems, refer to the "Technology"
brochure.<
Switching off DSC/Activating DTC
Press the DSC button briefly. The DTC indi-
cator lamp comes on and stays on.
DSC has been switched off; DTC is in ready
mode.
In the following exceptional circumstances,
it may be effective to activate the DTC for a
short period:
>When rocking the vehicle or starting off
in deep snow or on loose surfaces
>When driving on snow-covered grades,
in deep snow, or on a snow-covered
surface that has been packed down
from being driven on
>When driving with snow chains.
The gain in traction is achieved by a reduc-
tion in stabilizing intervention.
Switching off DSC and DTC
Hold the DSC switch down for at least
3 seconds. The DSC indicator lamp stays
lit.
In this case, no interventions to increase
stability and traction for the engine and
brakes are carried out.
To maintain vehicle stability, drive
with the DSC switched on whenever
possible.<
Reactivating DSC and DTC
Press the button again.
The indicator lamp goes out.
The laws of physics cannot be
repealed with DSC. It will always be the driver's responsibility to drive in a man-
ner that matches road conditions. We
therefore urge you to avoid using the addi-
tional safety margin of the system as an
excuse for taking risks. Stabilizing interven-
tion is only performed to a limited degree
when the DTC is activated.
Do not make any modifications to the DSC
system. Allow only authorized technicians
to perform service procedures on the
DSC.<
Dynamic Brake Control DBC
If you step on the brake rapidly, this system
automatically produces 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 applica-
tion. When the brake pedal is released, the
DBC is deactivated.
For more information on the system, refer
to the "Technology" brochure.
Brake Force Display
The Brake Force Display indicates to the
road user behind you how hard you are
braking.
The display has two levels:
>Normal braking:
Brake lamp 1 lights up on both sides of
the vehicle together with the center
brake lamp.

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>Forceful braking and braking with ABS:
Brake lamps 1 and 2 light up on both
vehicle sides together with the center
brake lamp.
Antilock Brake System ABS
The concept
ABS keeps the wheels from locking during
braking, thereby enhancing active driving
safety.
Malfunction
If the yellow indicator lamps for the
Antilock Brake System ABS come
on together with the brake warning
lamp and the indicator lamp for the
Dynamic Stability Control DSC:
The entire ABS and DSC control
system has failed. Continue driving
cautiously and defensively. Avoid
hard brake applications. Please have the
system checked by your BMW center as
soon as possible.
ABS and DSC indicator and warn-
ing lamps for Canadian models.
Braking with ABS
If you are in a situation which requires full
braking, you will exploit the full benefits of
the ABS system if you apply maximum
brake pressure – panic stop.
Pulsation at the brake pedal combines with
sounds from the hydraulic circuits to indi-
cate to the driver that ABS is in its active
mode.
Flat Tire Monitor
The concept
The tire pressure is determined using the
signals of the ABS sensors.
The system provides an alert whenever the
tire pressure of one tire drops relative to
that of another.
Prerequisites
In order for the system to "learn" the cor-
rect tire inflation pressures, please do the
following:
>Check the inflation pressure in all tires
>Compare to the inflation pressure table
– refer to page 72 – and correct if nec-
essary
>Initialize the system.
Check the tire pressures regularly
and correct if necessary. Refer to
page 71.<
Indicator lamp
In the event of a flat tire
The indicator lamp lights up red; in
addition, an acoustic signal is
sounded:
Respond immediately by carefully reducing
vehicle speed to under 50 mph / 80 km/h.
Avoid hard brake applications and steering
maneuvers.
If your vehicle is equipped with
Run Flat tires, note the information on
page 75.<
The Flat Tire Monitor cannot alert you
to severe and sudden tire damage
caused by external factors. Another factor
which the Flat Tire Monitor does not recog-
nize is the even and very gradual pressure
loss that takes place in all tires over an
extended period of time.<

Controlling the climate for pleasant driving
58
Tips for pleasant driving
Use the automatic system – switch on with
AUTO button 6. Select the desired interior
temperature.
Detailed setting options are described for
you below.
Automatic air distribution and
supply
The AUTO program assumes the
adjustment of the air distribution
and air supply for you and in addi-
tion adapts the temperature to
external influences – summer, winter – to
meet preferences you can specify.
Individual air distribution
You can also direct air flow onto
the windows , toward the
upper body and into the foot-
well as you require. The arrow
lights up. The automatic air supply remains
unchanged. All intermediate settings are
possible. By pressing the AUTO button,
you can reactivate the air distribution.
Temperature
The interior temperature that
appears on the display panel is a
general figure intended for refer-
ence purposes. When you start
the vehicle, the system ensures that the
selected temperature is reached as quickly
as possible. It then maintains this tempera-
ture, regardless of the season.
Air supply/blower
You can set the blower through
an infinitely variable range of
speeds. This shuts off the auto-
matic air supply. The arrow lights
up. The automatic air distribution remains
unchanged. You can reactivate the auto-
matic air supply by pressing the AUTO but-
ton.
When you turn the rotary control toward
zero: the blower, heating and air condi-
tioner are switched off, and the air supply is stopped. You can reactivate the system by
turning the control toward the right again.
To defrost windows and remove
condensation
This program quickly removes ice
and condensation from the wind-
shield and the side windows.
Maximum cooling
This program gives you maximum
cooling within a short period of
time.
The temperature is set to the lowest possi-
ble value. The system switches into the
recirculated air mode and air flows at max-
imum blower speed from the air outlets
only. Therefore, the air outlets must always
be open when you select this program.
Air conditioning
The air is cooled and dehumidi-
fied and – depending on the tem-
perature setting – rewarmed.
Depending on the weather, the
windshield may fog over briefly when the
engine is started.
The air conditioning system is automati-
cally switched on when you use the AUTO
program.
Condensation forms during operation
of the air conditioning system, which
then exits under the vehicle. Traces of con-
densed water on the ground underneath
the vehicle are thus normal.<
Outside air/Automatic recirculated
air control AUC/recirculated air
mode
You can respond to unpleasant
external odors or pollutants by
temporarily stopping the flow of
outside air. The system then
recirculates the air currently within the
vehicle.
By repeatedly pressing the button, you can
select one of three different operating
modes.

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>Indicator lamps off: outside air flows
into the vehicle
>Left-hand indicator lamp on – AUC
mode: the system detects pollutants in
the outside air and responds by deacti-
vating the outside airflow as required.
The system then recirculates the air
currently within the vehicle. Depending
on air quality requirements, the system
automatically switches between out-
side air supply and recirculation of the
air already within the vehicle
>Right-hand indicator lamp on: the flow
of outside air is permanently blocked.
The system recirculates the air already
within the vehicle.
If the windows fog over in the recir-
culated air mode, switch this mode
off and increase the air supply as re-
quired.<
Rear window defroster
The indicator lamp lights up when
the rear window defroster is
active. The rear window defroster
switches off automatically.
Ventilation
You can adjust the blower controls for the
upper body area to obtain the optimum air-
flow rates and directions for your personal
requirements:
1Rotary dials for opening and closing the
vents at any setting desired
2Lever for adjusting airflow direction
Microfilter/activated-charcoal filter
The built-in microfilter removes dust and
pollen from the incoming air. The activated-
charcoal filter provides additional protec-
tion by filtering gaseous pollutants from the
outside air. Your BMW center will replace
this combined filter as a standard part of
your scheduled maintenance. A substantial
reduction in airflow indicates that the filter
needs to be replaced earlier.

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Driving notes
Parking the vehicle
Condensation forms in the air conditioner
system during operation, which then exits
under the vehicle. Traces of condensed
water on the ground underneath the vehi-
cle are thus normal.
Brakes
Do not drive with your foot resting on
the brake pedal. Even light but con-
sistent pedal pressure can lead to high
temperatures, brake wear and possibly
even brake failure.
Hydroplaning
When driving on wet or slushy roads,
reduce vehicle speed. If you do not, a
wedge of water may form between the tires
and the road surface. This phenomenon
can lead to partial or complete loss of trac-
tion, vehicle control and braking effective-
ness.<
Driving through water
Do not drive through water on the
road if it is deeper than 1 ft / 30 cm,
and then only at walking speed. Otherwise,
the vehicle's engine, the electrical systems
and the transmission may be damaged.<
High temperatures
High temperatures occur with every
vehicle equipped with a catalytic con-
verter. 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 hot
exhaust system and flammable materials –
e.g. hay, leaves, grass, etc. Such contact
could lead to a fire, resulting in serious per-
sonal injury and property damage.<
Brake system
The brake warning lamp lights up
although the parking brake is not
engaged: check the brake fluid
level. It is very important that you follow the
instructions on page 81 before driving on.
Disc brakes
Corrosion
Limited vehicle use, extended periods with
the vehicle parked or in storage, and oper-
ating conditions in which braking is
restricted to gentle, low-pressure applica-
tions will all increase the tendency for cor-
rosion to form on the rotors and contamina-
tion to accumulate on the brake pads. This
occurs because the minimal pressure
which must be exerted by the pads to clean
the rotors by brake applications is not
reached.
If the brake rotors are corroded, they will
tend to respond to braking with a pulsating
effect which even extended application will
fail to cure.
Wet roads
When driving in heavy rain and on wet
roads, it is useful to apply light pressure
to the brake pedal every few miles. Watch
traffic conditions to ensure that this maneu-
ver does not endanger other road users.
The heat generated in this process helps
dry the pads and rotors to ensure that your
brake system will respond with undimin-
ished efficiency when you need it.
Inclines
Extended or steep mountain descents
should be driven in the gear or drive posi-
tion in which only minimal periodic brake
application is required. This helps avoid
placing excessive loads on the brake sys-
tem. Observe the maximum allowable
engine speed when doing so; refer to
page 47.
Do not coast with the clutch
depressed or with the transmission or
selector lever in Neutral. Do not coast with

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Wheels and tires
Tire inflation pressure
Information for your safety
The factory-approved Run Flat tires are
matched to the vehicle and have been
selected to provide optimum safety and
driving comfort.
It is not merely the tire's service life, but
also driving comfort and – above all else –
driving safety that depend on the condition
of the tires and the maintenance of the
specified tire pressure.
Incorrect tire inflation pressure is a fre-
quent cause of tire damage. It also signifi-
cantly influences the roadholding ability of
your BMW.
Check tire inflation pressures regu-
larly – at least every two weeks and
before every extended journey. If this is not
done, incorrect tire pressures can cause
driving instability or tire damage, ultimately
resulting in accidents.<
Checking tire pressures
The specified inflation pressures are pro-
vided on a sticker attached to the B-pillar
and are visible when the driver's door is
open.
All pressures are specified in the units usu-
ally used in your country – psi and kilopas-
cal – for tires at ambient temperatures; also
refer to the following tire inflation pressure
table.
Reinitialize the Flat Tire Monitor after
correcting the tire inflation pressure.
Refer to page 53.
Comply with tire approval
specifications
The inflation pressures in the table apply to
BMW-approved tire sizes and tire brands.
Your BMW center will be glad to supply this
information. Other tire brands may require
a higher inflation pressure, which may
impair handling and vehicle response.

Wheels and tires
72
Z4 roadster 2.5i
Z4 roadster 3.0i
TiresPressure specifications in psi/kPa
Tires
All pressure specifications in the table are
indicated in psi/kilopascal with cold tires –
cold = ambient temperature
225/50 R 16
225/45 R 17 30/210 33/230
225/40 R 18 30/210 –
245/40 R 17
255/35 R 18 –33/230
All winter tires 30/210 33/230
TiresPressure specifications in psi/kPa
Tires
All pressure specifications in the table are
indicated in psi/kilopascal with cold tires –
cold = ambient temperature
225/45 R 17 33/230 36/250
225/40 R 18 33/230 –
245/40 R 17
255/35 R 18 –36/250
All winter tires 33/230 36/250

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Tire condition
Tire tread – Tire damage
Inspect your tires frequently for tread wear,
signs of damage and for foreign objects
lodged in the tread. Check the tread depth.
Tread depth should not be allowed to go
below
1/8 in / 3 mm, even though in
Europe, for example, the legally specified
minimum tread depth is only
1/16 in /
1.6 mm.
Tread wear indicators in the tread-groove
base – see arrow – are distributed around
the wheel circumference and are labeled
on the tire sidewall as TWI – Tread Wear
Indicator. At a tread depth of
1/16 in /
1.6 mm, the indicators signal that the
legally permissible wear limit has been
reached.
Avoid overloading the vehicle so that
the permitted load on the tires is not
exceeded. Overloading can cause over-
heating and damage inside the tires.
The ultimate result can assume the form of
a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate tire
failure or some other vehicle malfunction.
This type of problem can be caused by
contact with curbs, etc. This is also true for
irregularities in the vehicle's handling char-
acteristics, such as a pronounced ten-
dency to pull to the left or right. Should this
occur, respond by immediately reducing
your speed. Proceed carefully to the near-
est BMW center or professional tire center,
or have the vehicle towed there to have it
and its wheels or tires inspected.
Tire damage – up to and including sudden and complete air loss – can pose an
extreme hazard for both vehicle occupants
and other road users.<
Tire replacement
To maintain good handling and vehicle
response, use tires of a single tread config-
uration from a single manufacturer.
BMW advises against using retreaded
tires as this could negatively affect
driving safety. This is due to possible varia-
tions in casing structures and, in some
cases, to their extreme age, factors which
can lead to a decrease in their durability.<
Tire age
The date on which the tire was manufac-
tured is indicated by the code on the side-
wall:
DOT … 3602 indicates that the tire was
manufactured in week 36 of the year 2002.
BMW recommends the replacement of all
tires every 6 years at the latest, even if a tire
usage of 10 years is possible.
Run Flat tires
When replacing tires, always use
Run Flat tires since a spare wheel is
not provided to replace a flat tire.
Run Flat tires are labeled on the sidewall
with a circular symbol containing the letters
RSC. Refer to page 75.<
DOT quality grades
Tread wear
Traction AA A B C
Temperature A B C
All passenger car tires must conform
to Federal Safety Requirements in
addition to these grades.<
Tread wear
The tread wear grade is a comparative rat-
ing based on the wear rate of the tire when
tested under controlled conditions on a
specified government test course.
For example, a tire graded 150 would wear

Wheels and tires
74 one and one-half (1 γ) times as well on the
government course as a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm due to variations in driving habits,
service practices and differences in road
characteristics and climate.
Traction
The 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 specified govern-
ment 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 brak-
ing traction tests, and does not include
acceleration, cornering, hydroplaning, or
peak traction characteristics.<
Temperature
The 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 conditions 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 sudden tire failure. 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 repre-
sent 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, under-inflation, or excessive load-
ing, either separately or in combination,
can cause heat buildup and possible tire
failure.<
Uniform Tire Quality Grading
Quality grades can be found where appli-
cable on the tire sidewall between tread
shoulder and maximum section width. For
example:
Tread wear 200 Traction AA
Temperature A
Wheel and tire combina-
tions
The right choice
Use wheels and tires approved by
BMW for your particular vehicle. Vari-
ations in factors such as manufacturing tol-
erances mean that even wheels and tires
with identical official size ratings could
actually have dimensions different from the
approved units. These differences could
lead to body contact, and with it the risk of
severe accidents. If non-approved wheels
and tires are used, BMW cannot evaluate
their suitability, and therefore cannot be
held liable for driving safety.<
BMW tests certain tire brands for each tire
size, classifies them as road-safe and
approves them. Consult your BMW center
for more information. Observe any country-
specific regulations, e.g. on making a cor-
responding entry in the vehicle documents.
The correct wheel and tire combina-
tion affects different systems such as
ABS, DSC, DTC and DBC. The function of
these systems is impaired if improper
wheel and tire combinations are used.
For this reason, use tires of the same brand
and tread configuration. In the event of a
flat tire, for example, remount the approved
wheel and tire combination as soon as pos-
sible.<

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Run Flat tires
Run Flat tires are labeled on the sidewall
with a circular symbol containing the letters
RSC.
Run Flat tires consist of self-supporting
tires and special rims. The tire reinforce-
ment ensures that the tire retains some
residual safety in the event of pressure
drop and driving remains possible to a
restricted degree.
Because the sides of the Run Flat
tires are reinforced, a drop in inflation
pressure usually cannot be detected from
the outside.<
Flat tire
The red warning lamp in the instru-
ment cluster lights up when a tire
has failed. In addition, an acoustic
signal is heard. Refer to pages 14, 53.
1.Reduce vehicle speed carefully to
under 50 mph / 80 km/h. Avoid hard
brake applications and steering maneu-
vers
2.Do not exceed 50 mph / 80 km/h again
3.Find out which tire has been damaged;
to do so, check the tire inflation pres-
sure of all four tires at the earliest
opportunity. Refer to page 71
4.Correct the tire inflation pressure if you
wish to continue driving and if it is safe
to do so. Refer to the following section
5.Have the damaged tires changed by
your BMW center.
BMW recommends that you consult
your BMW center if you wish to replace the tires of your BMW, or change
from summer to winter tires or vice versa.
Your BMW center knows how to work with
Run Flat tires and is equipped with the nec-
essary special tools.<
For safety reasons, do not have Run
Flat tires repaired.
When replacing tires or changing from
summer to winter tires – or vice versa – use
Run Flat tires only since a spare tire will not
be available in the event of a flat tire.<
Driving with a damaged tire
When using Run Flat tires, you can con-
tinue driving cautiously at a maximum
speed of 50 mph / 80 km/h, depending on
the cargo load and the extent of tire dam-
age.
You can estimate the distance you can
continue driving on the basis of the follow-
ing values:
>Tire inflation pressure of 0 psi / 0 kPa:
approx. 100 miles / 150 km
>Tire inflation pressure of 7 – 15 psi
50 – 100 kPa:
approx. 300 miles / 500 km
>Tire inflation pressure greater than
15 psi / 100 kPa:
approx. 600 miles / 1,000 km.
Drive cautiously and do not exceed a
speed of 50 mph / 80 km/h. In the
event of pressure loss, changes in handling
characteristics – such as reduced stability
when braking, increased stopping dis-
tance, and altered steering response – may
occur.<