1998 BMW CONVERTIBLE ESP

84
Automatic Stability Control plus
Traction (ASC+T)This system is designed to enhance
operating stability, especially while
accelerating and during cornering.
ASC+T automatically assumes opera-
tion each time you start the engine.
The indicator lamp in the instrument
cluster goes out shortly after you switch
on the ignition.
To deactivate the systemPress the button; the indicator lamp
comes on.To reactivate the systemPress the button again; the indicator
lamp goes out.Indicator lamp flashesThe system is actively regulating drive
torque in response to monitored vehicle
operating conditions.Indicator lamp fails to go out after
the engine is started, or comes on
in the course of normal vehicle
operationThe system has a defect. The vehicle
normally remains operational even with-
out ASC+T. Consult your authorized
BMW Retailer for repair.When ASC+T is switched off, you drive
with a conventional drive system. We
recommend that you deactivate the
system for increased traction
dwhen rocking the vehicle or starting
off in deep snow or on loose surfaces
(refer to "Starting off", page 10 5)
dor when driving with snow chains.
b
But even with ASC+T the laws of
physics can not be suspended. Any
consequences arising from traction loss
due to excessive vehicle speed remain
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.c
For more details, please refer to section
"Advanced Technology" on page 156.
ASC
360de064ASC+T

89
At a glanceControls Car careRepairsTechnicalDataIndex
1 Air ßow directed against windshield
and door windows
2 Air ßow toward upper body
The rotary dial on the right affords
continuous opening or closing of the
air supply, the lever changes the
direction of the air ßow. The rotary dial
on the left tempers the air coming out
(page 92).
3 Front footwell ventilation
Corresponding vent outlets are also
located in the rear footwell.
4 ControlsAutomatic climate control

91
At a glanceControls Car careRepairsTechnicalDataIndex
To defrost windshield and door
windows
Air conditioner Circulated air mode/Automatic
recirculated air control (AUC)
*
Press the button repeatedly to run
through the following control sequence:
dIndicator lamps off: outside air flow
operational.
dLeft-hand indicator lamp on Ð AUC
mode: the system detects pollutants
in the outside air and responds by
deactivating the outside air flow as
required. The system then recircu-
lates the air currently within the vehi-
cle.
dRight-hand indicator lamp on: the
flow of outside air into the vehicle is
permanently blocked. The system
then recirculates the air currently
within the vehicle.a
If the windshields fog over in circu-
lated air mode, switch off the circulated
air mode/Automatic recirculated air
control and increase the air supply. if
necessary.c
Rear window defrosterBMW Convertible: Heated rear-window
blower.
The rear-window blower is always
switched off with the convertible top
down.
When the hardtop
* is in place, press
the rear-window heating button.
Temperature
This program is designed for
rapid removal of ice and con-
densation from the windshield and side
windows.
The air conditioner cools and
dehumidifies incoming air
before reheating it to the selected tem-
perature.
Depending on the weather, the wind-
shield may fog over briefly when the
engine is started.
Switching off the air conditioner at out-
side temperatures below approx. 41 5F
(56) will prevent the windows from
fogging up.
Frequently switching the air condi-
tioner on and off may also promote the
formation of condensation on the win-
dow surfaces.
b
Condensation forms in the air
conditioner system during operation,
which then exits under the vehicle. It is
not unusual for a small puddle to form
there.c
You can respond to unpleas-
ant odors in the outside air
by temporarily excluding the outside air.
The system then recirculates the air
currently within the vehicle.
A
The indicator lamp comes
on to confirm that the rear
defroster is operating.
The defroster switches off automatically
after approx. 15 minutes.
On both the driver's and the
passenger's side you can
adjust the specific temperature. The fig-
ures in the display provide a general
indication of interior temperature. We
recommend 70 5F (226) as a standard
setting for comfortable travel, both with
and without the air conditioner. When
you start the vehicle, the system
ensures that the selected temperature
is achieved as quickly as possible and
maintained at a constant level by the
control.
Automatic climate control

10 0
To ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you
observe the following.
Engine and differentialUp to 1,250 miles (2,000 km):
Drive at different engine speeds and
vehicle speeds, but be careful not to
exceed the following engine speed:
4,500 rpm
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
After 1,250 miles (2,000 km) you can
gradually increase the number of revo-
lutions or the speed.
You should also observe these break-in
procedures if the engine or differential
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. This
means that you should drive with addi-
tional caution for the first 200 miles
(300 km).Brake systemBrake pads and disks attain their opti-
mal wear patterns only after approx.
300 miles (500 km).
EngineDo not allow the engine to warm to its
normal operating temperature by leav-
ing it idling with the vehicle parked.
However, when starting in extremely
cold weather it is a good idea to allow
the engine to run at fast idle for about
30 seconds before getting underway;
this precaution ensures adequate lubri-
cation.
Avoid high engine speeds while the
engine is still cold; this helps avoid pre-
mature wear and reduced service life.
When driving under high engine loads
(acceleration, steep hills), try to keep
the engine running above 1,500 rpm.
We recommend downshifting into a
more suitable range, especially when
driving up extended inclines.
It is a good idea to follow extended
periods of low-speed operation (dense
urban traffic, stop-and-go driving) by
maintaining an engine speed consis-
tently above 3,000 rpm for several
miles. This procedure helps prevent
deposits from accumulating in the
engine.
Break-in procedures Driving notes

10 2
The catalytic converter reduces harmful
exhaust emissions.
It is designed for use with unleaded fuel
only.
Even minute quantities of lead would be
enough to permanently damage both
the catalytic converter and the system's
oxygen sensor.
To ensure efficient, trouble-free engine
operation and avoid potential damage:
dAlways have your car serviced in
accordance with maintenance
instructions.
dNever continue driving until the fuel
tank is empty.
dRespond to engine miss by switching
off the engine at once.
dNever tow-start the car unless the
engine is cold, or else unburned fuel
may reach the catalytic converter.
Better yet: use jumper cables!
dAvoid other situations in which the
fuel would not be (completely)
burned, for instance:
Frequent, extended, or repeated
starting attempts during which the
engine fails to start. (Switching off
and restarting a healthy engine
causes no damage).
Never let the engine run with any of
the spark-plug cables disconnected.
a
Always observe the above points
to prevent unburned mixture from
entering the catalytic converter. This
could result in overheating, leading to
serious damage.
High temperatures occur on all vehicles
equipped with a catalytic converter.
Heat shields are installed adjacent to
some sections of the exhaust system.
Never remove these shields; do not
apply undercoating to their surfaces.
When driving, standing at idle or park-
ing the vehicle, take care to avoid con-
tact between the exhaust system and
flammable materials (e.g., grass, hay,
leaves, etc.). Such contact could lead to
a fire, resulting in personal injury and
property damage.c
Traveling abroadAlways make sure that unleaded fuel
meeting your engineÕs octane require-
ments will be available when planning
trips outside the country. The use of
fuel failing to meet the official octane
requirements could result in engine
damage.
If you are considering traveling to a
country in which unleaded fuel is not
readily available, please remember that
leaded fuel will destroy the lambda oxy-
gen sensor and the catalytic converter
on your BMW. After operation on
leaded fuel, your vehicle will no longer
meet American and Canadian exhaust
emission standards, and there will also
be a loss of fuel economy. Upon your
return to the US or Canada, you will be
expected to comply with legal ordi-
nances requiring that you replace both
the oxygen sensor and the catalytic
converter, and to have the fuel system
flushed to remove any traces of leaded
fuel.
Catalytic converter

10 3
At a glanceControlsCar careRepairsTechnicalDataIndex
ABS enhances active safety by helping
to prevent the wheels from locking under
braking. 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
uncontrolled oversteer.
ABS is designed to meet two essential
requirements during every application:
dto help provide vehicle stability on all
types of road surface (asphalt,
cement, dirt, moisture, snow and ice).
dto help to retain steering and maneu-
vering capability under the same con-
ditions.
However, certain important consider-
ations must be borne in mind in connec-
tion with these requirements:
Not even ABS can suspend the normal
laws of physics. ABS alone can not pre-
vent accidents when the brakes are
applied without an adequate safety
interval between vehicles, when the car
reaches excessive rates of lateral accel-
eration in curves, or if aquaplaning
occurs. Responsibility for these types of
situations remains in the hands (and 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.
Driving with ABSThe yellow ABS warning in the instru-
ment panel goes out as soon as the
engine is started.
The system becomes operative once the
vehicle exceeds a speed of 5 mph
(8 km/h). The ABS is deactivated when-
ever the vehicle's speed drops below
approx. 2 mph (3 km/h). This means that
the wheels can lock in the Þnal phase of
a braking action - a factor of no signiÞ-
cance in actual practice.
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 car is within its maximum braking
range. In addition, the audible pulsation
that accompanies the control operation
calls your attention to the reduced trac-
tion between tires and road surface
(marginal adhesion), and reminds you
that the vehicle's speed should be
reduced to adapt to road conditions.On road surfaces featuring a loose top
layer on a Þrmer substratum, e.g., on
gravel or snow, the braking distances
with ABS may be longer than with the
wheels locked. However, ABS continues
to provide enhanced vehicle and steer-
ing control under these conditions.
a
To ensure that the system remains
completely operational, never modify the
ABS. Service procedures on ABS are to
be performed by authorized technicians
only.c
ABS may fail to function with maximum
efÞciency when tires of different sizes
are mounted (e.g., winter tires/spare tire;
remount the correct tires at all wheels as
soon as possible).
In the event of a fault, the ABS warning
lamp in the instrument cluster lights up,
refer to page 18. The braking system
then reverts to conventional operation as
on a vehicle without ABS. However,
have the brake system checked by your
BMW Retailer as soon as possible. To
prevent undetected defects and cumu-
lative faults from adversely affecting the
brake system, refer any problems to
your authorized BMW Retailer at the
earliest opportunity.
Antilock Brake System (ABS)

10 4
Disc brakes furnish optimum decelera-
tion and braking control as well as
greater fade resistance under heavy
use.
Limited vehicle use, extended periods
with the car parked or in storage and
light loading will increase the tendency
for corrosion to form on the rotors, and
dirt to accumulate on the pads. This
happens because the minimum pres-
sure between the pad and the disc
required for the self-cleaning function
of the disc brakes is not achieved.
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.
a
Use only original BMW-approved
brake pads, as otherwise vehicle autho-
rization is no longer valid.c
Driving notes While driving in wet conditions and in
heavy rain, it is a good idea to apply
light pressure to the brake pedal every
few miles - Watch traffic conditions to
ensure that this maneuver does not
endanger other road users. The heat
generated in this braking process helps
dry the brake pads and rotors.
Maximum braking force is obtained
while the wheels continue to rotate,
peaking when the wheels remain on the
verge of locking without actually doing
so. ABS maintains this state automati-
cally. If the ABS fails, you should revert
to the staggered braking technique
described above (refer to page 106).
Extended or steep mountain descents
do not necessarily have to lead to
reduced braking efficiency; downshift
to a gear in which only minimal periodic
brake applications are required (you
can move the selector lever to the
appropriate lower range if your car is
equipped with an automatic transmis-
sion).
You can further increase the engine's
braking effect by selecting a lower gear,
downshifting as far as first gear or plac-
ing the selector lever in position 1 (2).Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate the vehicle by applying more
substantial force at the pedal (watch for
following traffic!) and then pausing
before repeating the application. This
staggered braking technique allows the
brakes to cool in the intervals between
active braking phases, preventing over-
heating and ensuring that full braking
capacity remains available at all times.
a
Do not allow the vehicle to coast by
pressing down the clutch pedal or shift-
ing into neutral while underway. Never
drive with the engine switched
off (!). The engine provides no braking
effect when the clutch is disengaged or
the transmission is in neutral, and there
is no power-assist for brakes and steer-
ing when the engine is not running.
Never allow floor mats, carpets or other
objects to protrude into the area around
the accelerator, clutch and brake pedals
and obstruct their movement.c
Disc brakes

10 5
At a glanceControlsCar careRepairsTechnicalDataIndex
Failure of one brake circuitPedal travel increases, more pressure is
required at the pedal.
The remaining circuit continues to pro-
vide good braking response.a
In the event of any malfunction in
the brake system, consult the nearest
BMW Retailer as soon as possible.cThe onset of winter is often accompa-
nied by rapid changes in weather.
Adaptations in driving style should be
accompanied by preparations on the
vehicle itself to ensure that your
progress through the winter remains
safe and trouble-free.
CoolantEnsure that the coolant contains the
year-round 50:50 ratio of water and
antifreeze with corrosion inhibitor. This
mixture provides protection against
freezing down to approximately -345F
(-376). Replace the coolant every
three years.Lockscan be made operative again using
BMW lock de-icer. This de-icer also
contains lubricants.
In addition, a treatment with BMW lock
cylinder grease is recommended.Rubber seals and components To prevent the weather-stripping from
freezing, apply a spray-on rubber treat-
ment or silicone spray to the door, hood
and luggage compartment lid seals.b
A complete range of car-care
products is available from any autho-
rized BMW Retailer.c
Snow chainsBMW snow chains
* can be mounted on
both summer and winter tires. Mount
them in pairs on the rear wheels only
and observe the manufacturer's safety
precautions. Do not exceed a maximum
speed of 30 mph (50 km/h). For maxi-
mum traction, deactivate ASC+T when
driving with snow chains mounted, refer
to page 84.
Starting offWhen driving off in deep snow or "rock-
ing" the vehicle to free it, you should
switch off ASC+T, refer to page 84. Driving on low-traction road
surfacesOperate the accelerator pedal sensi-
tively, avoid high engine speeds and
shift up to the next-higher gear early.
Shift down into the next lowest gear
when approaching uphill or downhill
grades. Maintain an adequate distance
between yourself and the car ahead.
Brake system Winter driving