Asc - BMW F 800 GS Adventure Rider's Manual

Electronic engine
management with
BMW Motorrad ASC
with Automatic Stability Control

(ASC)

OE
How does ASC work?
The BMW Motorrad ASC system
compares the speed of rotation
of the front wheel and the rear
wheel. The differential is used to
compute slip as a measure of the
reserves of stability available at
the rear wheel. If slip exceeds a
certain limit the engine control in-
tervenes, adapting engine torque
accordingly.
What is the design
baseline for
BMW Motorrad ASC?
The BMW Motorrad ASC is an
assistant system for the rider for
use on public roads. The ex-
tent to which the rider affects
ASC control can be consider-
able (weight shifts when corner-
ing, items of luggage loose on
the motorcycle), especially when
style of riding takes rider and ma-
chine close to the limits imposed
by physics.
For off-road driving the riding
mode ENDURO should be ac-
tivated. This mode delays ASC
intervention slightly in order to
permit controlled drifting.
The system is not optimised for
special requirements that apply
under extreme competitive situ-
ations off-road or on the race
course. The BMW Motorrad
ASC can be deactivated in these
cases.
WARNING
Risky riding.
Risk of accident despite ASC.
Invariably, it remains the rider's
responsibility to adapt riding
style to riding conditions.
Do not take risks that would
negate the additional safety
offered by this system.
Special situations
In accordance with the laws of
physics, the ability to accelerate
is restricted more and more as
the angle of heel increases. Con-
sequently, there can be a per-
ceptible reduction in acceleration
out of very tight bends.
The speeds of the front and
rear wheels are compared as
one means of detecting the rear
wheel's incipient tendency to
spin or slip sideways. If the sys-
tem registers implausible values
for a lengthy period the ASC
function is deactivated for safety
reasons and an ASC fault mes-
sage is issued. Self-diagnosis
has to complete before fault
messages can be issued.
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