air condition BMW 740I 1998 User Guide

92n
ASC+T/DSC
*
Automatic Stability Control plus
Traction (ASC+T)/Dynamic
Stability Control (DSC)
*
These systems help provide additional
dynamic stability, particularly when ac-
celerating and cornering.
The DSC system enhances the benefits
of the ASC+T. In addition to optimizing
vehicle stability and traction when ac-
celerating or starting from a standstill,
another benefit is realized in cornering
stability. Of course, this is subject to the
limits imposed by the laws of physics.
The system activates automatically
each time you start the engine.380de621
Indicator lamp
The indicator light in the instru-
ment cluster goes out shortly af-
ter you switch on the ignition.
Refer to page 21.
Indicator lamp flashes:
The system is actively regulating drive
torque in response to monitored vehicle
operating conditions.
If the indicator lamp fails to go out after
the engine is started, or if it comes on
during normal driving:
If the system has not been deactivated,
there is a system malfunction. The vehi-
cle remains operational, but without
ASC+T/DSC. Consult your authorized
BMW center for repair.
To deactivate the systemPress the button. The indicator lamp
will come on.
Depending on equipment options, the
button is marked with ASC or DSC.
With deactivated ASC+T/DSC you are
driving with conventional, unregulated
torque transfer.
We recommend that you deactivate the
system for increased traction:
>When rocking the vehicle or starting
off in deep snow or on loose surfaces
>or when driving with snow chains.
Refer also to page 129.To reactivate the systemPress the button again; the indicator
lamp goes out.
The laws of physics cannot be re-
pealed, even with ASC+T/DSC.
Any consequences arising from traction
loss due to excessive vehicle speed re-
main the responsibility of the driver. For
this reason, do not take risks, using the
additional safety margin provided by the
system as an excuse.<
For additional details concerning
ASC+T/DSC, please refer to the chap-
ter describing "Advanced technology"
on page 185.

93n
RepairsIndexOverview Controls Car care Technology Data
Electronic Damper Control (EDC)
*
The system automatically ensures
damping of the running gear on de-
mand and thus increases comfort and
driving safety.Automatic adaptationAutomatic adaptation is activated after
every engine start. It can be maintained
throughout the entire vehicle speed
range and for all load conditions. If op-
erating parameters (road-surface qual-
ity, driving conditions such as steering,
braking, others) change, the damping
system adapts automatically to the new
factors in fractions of a second.380de620
Sport programWith the ignition key in position 2, press
the EDC button (arrow). The indicator
lamp next to the S comes on.
The Sport program should be invoked
when you wish to have strictly perfor-
mance-oriented tuning of the running
gear under all operating conditions.
To switch to automatic adaptation:
Press the button again; the indicator
lamp goes out.

95n
RepairsIndexOverview Controls Car care Technology Data
Tire Pressure Control (RDC)
*
Flat tireIf there is a tire failure with a loss of air
pressure, the message "TIRE DEFECT"
appears in the Check Control. In addi-
tion, a gong sounds.
If this occurs, reduce vehicle speed im-
mediately and stop the vehicle. Avoid
hard brake applications. Do not over-
steer. Replace the wheel and flat tire.
The spare tire which is available in
your vehicle as standard equip-
ment is equipped with the electronics
required for RDC and, following activa-
tion of the system, is also monitored af-
ter it is mounted.<
The RDC cannot alert you to se-
vere and sudden tire damage
caused by external factors.<
Have the tires changed by your
authorized BMW center.
Your authorized BMW center has been
trained to work with the RDC system
and is equipped with the necessary
special tools to do so.<
System interferenceUnder certain local conditions, the RDC
may malfunction for brief periods be-
cause of interference from outside sys-
tems or electronic devices which have
the same radio frequency.
During the period of the malfunction,
the message "TIRE CONTROL INAC-
TIVE" appears in the Check Control.
You will also see the same message
>in the event of a system fault
>if a wheel is mounted without the
RDC electronics
>if, in addition to the spare tire, addi-
tional wheels with RDC electronics
are on board.
Please contact your authorized BMW
center for additional information.

101n
RepairsIndexOverview Controls Car care Technology Data
Automatic climate control1 Air flow directed against windshield
and door windows
2 Air flow toward the upper body
The rotary dials allow infinitely-vari-
able regulation of the air supply,
changes in the air-flow direction,
and temperature regulation.
(Change air-flow direction in the
rear passenger area with the levers
in the center of the vent). In the
closed position, air flows out at the
upper center of the instrument
panel only104
3 Front footwell ventilation
There are corresponding air vents in
the rear footwell as well
4 Automatic air distribution –
left-hand side102
5 Individual air distribution –
left-hand side102
6 Temperature control –
left-hand side103
7 Temperature and air flow display,
left- and right-hand
sides103,104
8 Temperature control –
right-hand side103
9 Residual heat mode104
10 Individual air distribution –
right-hand side10211 Automatic air distribution –
right-hand side102
12 Air supply – right-hand side104
13 Recirculated-air mode/Automatic
recirculated-air control (AUC)103
14 Air conditioner103
15 Rear window defroster70, 103
16 Defrosting the windows and remove
condensation103
17 Air grill for interior temperature sen-
sor - please keep clear and unob-
structed
18 Air supply – left-hand side104

102n
Automatic climate controlTips for pleasant drivingUse the automatic system, i.e., press
AUTO button 4. Select an interior tem-
perature that is comfortable for you -
we recommend 707 (226) as a com-
fortable setting. When the outside tem-
perature is above 427 (56), you can
also use the air conditioning system 14.
This will dry the air and prevent window
fogging, for example if people are wear-
ing damp clothes in the vehicle. Set the
outlets 2 so that the air flows past you
and does not flow directly at you. Set
the rotary dial between the air outlets 2
for the upper body to a medium posi-
tion, since air that is somewhat cooler
promotes driving without fatigue.
The following description will guide you
through additional individual settings.
You can make the settings of your
vehicle in such a manner that,
when you unlock the car with your per-
sonalized remote control, your own per-
sonalized setting of the automatic cli-
mate control is initiated.<
Automatic air distribution
The AUTO program as-
sumes the adjustment of
the air distribution and the air supply for
you and in addition adapts the tempera-
ture to external influences (summer,
winter) to meet preferences you can
specify. This program maintains a com-
fortable in-car climate regardless of the
season. Select an interior temperature
that is comfortable for you - we recom-
mend 707 (226) as a comfortable
setting.
The temperature setting and the word
"AUTO" for the air flow appear in the
display 7 (refer to the overview on
page 100). Open the ventilation outlet
for the upper body area. Switch on the
air conditioner in warm weather. The
maximum cooling capacity is achieved
when you set the rotary dial 3 (refer to
page 104) to cold.
Individual air distribution
You can cancel the AUTO
program by selecting spe-
cific distribution patterns to
suit your own individual re-
quirements. You can direct
air to flow onto the windows , toward
the upper body , and into the footwell
.
To defrost windshield and door
windows
This program quickly removes
ice and condensation from the
windshield and the side windows.
Air conditioner
The air is cooled and dehumidi-
fied and - depending on the tem-
perature setting - warmed again when
the air conditioner system is switched
on.
Depending on the weather, the wind-
shield may fog over briefly when the en-
gine is started.
At outside temperatures below approx.
427 (56), switch off the air condi-
tioner. This will help to prevent the win-
dows from fogging up.
If the windows fog over immediately af-
ter the air conditioner is switched off,
switch it back on.
Condensation forms in the air con-
ditioner system during operation,
which then exits under the vehicle.
Traces of condensed water of this kind
are thus normal.<

103n
RepairsIndexOverview Controls Car care Technology Data
Automatic climate controlAutomatic recirculated-air control
(AUC)
You can respond to unpleasant
external odors by temporarily
stopping the flow of outside air. The
system then recirculates the air cur-
rently within the vehicle. Press the but-
ton repeatedly to run through the fol-
lowing control sequence:
>Indicator lamps off: Fresh air flows
into the vehicle
>Left-hand indicator lamp on – AUC
mode: The system detects pollutants
in the outside air and responds by
deactivating the outside air flow when
required. The system then recircu-
lates the air currently within the vehi-
cle
>Right-hand indicator lamp on: The
flow of external air into the vehicle is
permanently blocked. The system
then recirculates the air currently
within the vehicle.
If you have a multi-function steering
wheel with the AUC button (refer to
page 23), you can also switch between
"OFF" and AUC from there.
If the windows fog over in the re-
circulated-air mode, switch this
mode off and increase the air supply as
required.<
Rear window defroster
When the rear window defroster
is activated, the indicator lamp
comes on. The rear window defroster
switches off automatically.
Temperature
You can make individual
temperature settings on the
driver's side and the front passenger
side. Your settings will be shown in the
display 7. The displayed temperatures
are reference values for the interior
temperature. We recommend 707
(226) as a comfortable setting,
whether the air conditioner is operating
or not. When you start the vehicle, the
system ensures that the selected tem-
perature is achieved as quickly as pos-
sible. It then maintains this tempera-
ture, regardless of the season.
You can set uncontrolled heater
output at up to 907 (326). Full
cooling output is available from the air
conditioner down to 607 (166).<

Air supply
In the "AUTO" program, the
air flow is controlled auto-
matically. AUTO will appear in the dis-
play, refer to the overview on page 100.
Use "+" and "–" to vary the air flow.
When your setting is displayed by bars,
the automatic air flow is switched off.
Automatic air distribution maintains its
setting. You can reactivate the auto-
matic air flow by pressing the "AUTO"
button.
When you press "– " during operation at
minimum blower speed all displays are
canceled: The fan, heating and air con-
ditioner are switched off. The outside
air supply is closed. By pressing any
button of the automatic climate control
(except the "REST" button 9), you can
switch the system back on.

105n
RepairsIndexOverview Controls Car care Technology Data
Automatic climate control Rear passenger-area air conditioning
*
Microfilter, activated-charcoal
filterThe microfilter removes dust and pollen
from the incoming air. The activated-
charcoal filter provides additional pro-
tection by filtering gaseous pollutants
from the outside air. Your BMW center
replaces the filter assemblies as a stan-
dard part of your scheduled mainte-
nance. A substantial reduction in air
flow indicates that the filter needs to be
replaced early.
1 Display for temperature and air
supply
2 Temperature/
Switching the system on
3 Air supply/
Switching the system on
380de636
2 TemperatureThe rear passengers can adjust the
temperature for the ventilation outlets
which are positioned above this as de-
sired. The figures in the display provide
a general indication of interior tempera-
ture. We recommend 707 (226) as a
comfortable setting, whether the air
conditioner is operating or not. When
you start the vehicle, the system en-
sures that the selected temperature is
achieved as quickly as possible. It then
maintains this temperature, regardless
of the season.3 Air supplyWhen you press "–" in the lowest
blower speed, all of the displays are
canceled: This setting deactivates the
blower and shuts off the air supply. You
can then switch the rear air conditioner
back on by pressing the button again.
The air flow in the rear will vary accord-
ing to the settings selected at the front.

Overview
Controls and features
Operation, care
and maintenance
Owner service procedures
Technical data
Index Advanced technology
121n
RepairsIndexOverview Controls Car care Technology Data
Special operating instructions:
Break-in procedure122
Driving notes123
Catalytic converter124
Antilock Brake System
(ABS)125
Disc brakes126
Brake system128
Winter operation128
Power steering130
Level control system130
Cellular phone131
Radio reception131
Wheels and tires:
Tire inflation pressure132
Tire condition132
Tire replacement133
Tire rotation133
Wheel and tire
combinations134
Winter tires135
Snow chains135
Approved wheel and tire
specifications136Under the hood:
Hood137
Engine compartment138
Washer fluids142
Washer nozzles142
Engine oil143
Coolant146
Brake fluid147
Oil for power steering/
Level control system148
Vehicle Identification
Number148
Care and maintenance:
The BMW Maintenance
System149
Caring for your car150
Airbags156
Vehicle storage156
Laws and regulations:
Technical modifications to the
vehicle157
OBD connector158

125n
RepairsIndexOverview Controls Car care Technology Data
Antilock Brake System (ABS)The conceptABS enhances active safety by helping
to prevent the wheels from locking dur-
ing brake applications. The reason:
Locked wheels are dangerous. When
the front wheels slide, the driver loses
steering control over the vehicle. Trac-
tion loss at the rear wheels can cause
the rear end to break into an uncon-
trolled skid.
The system can achieve the shortest
braking distances possible under most
conditions (on straights and in curves,
on asphalt, ice, wet road surfaces, etc.).
ABS is designed to meet two essential
requirements during every brake appli-
cation:
>To help provide vehicle stability
>To help maintain steering control and
maneuverability – on all types of road
surfaces (asphalt, concrete, mud, wet
pavement, snow, ice).
Braking with ABSThe system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). The ABS is deactivated
whenever the vehicle's speed drops
back below approx. 4 mph (6 km/h). This
means that the wheels can lock in the fi-
nal phase of a panic stop – a factor of no
significance in actual use.
If you are in a situation which requires
full braking, you will exploit the full bene-
fits of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering ef-
fort, despite the full brake application.
The ABS system closed-loop control cir-
cuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation – a
result of the control function cycles – in-
dicates to the driver that vehicle speed
should be reduced to adapt to road sur-
face conditions when there is reduced
traction and grip between tires and road
surface (slippery road surface).
Always depress the brake pedal with
constant pressure. Keep the brake pedal
down. Do not pump the brakes.In driving conditions where there is a
loose upper surface together with a
subsurface which provides better trac-
tion (on gravel or snow, for instance), or
with snow chains, the braking distance
may also be longer than when the
wheels are locked. However, ABS con-
tinues to provide enhanced vehicle sta-
bility and steering response under
these conditions.
Information for your safetyNot even ABS can suspend the laws of
physics. ABS alone cannot prevent ac-
cidents when the brakes are applied
without an adequate safety interval be-
tween vehicles, if the car is driven at an
excessive rate of speed in curves, or if
aquaplaning 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 se-
curity, or mislead you into taking in-
creased 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.<

126n
Antilock Brake System (ABS) Disc brakesIn the event of a fault
If the ABS warning lamp in the
instrument cluster comes on, re-
fer to page 21. The brake sys-
tem then reverts to conventional
operation as on vehicles without
ABS. However, have the brake
system checked by your BMW center
as soon as possible. To prevent unde-
tected defects and cumulative faults
from adversely affecting the brake sys-
tem, refer any problems to your autho-
rized BMW center at the earliest oppor-
tunity.
Disc brakes furnish optimum decelera-
tion and braking control and greater
fade resistance under heavy use.
When the vehicle is driven only occa-
sionally, during extended periods when
the vehicle is not used at all, and in op-
erating conditions where brake applica-
tions are less frequent, there is an in-
creased tendency for corrosion of the
rotors and accumulation of contamina-
tion on the brake pads. This occurs be-
cause the minimal pressure which must
be exerted by the pads to clean the ro-
tors 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.
We recommend the use of original
BMW brake pads and compo-
nents, otherwise driving safety can be
impaired.<