Engine Drag Torque Control - BMW S 1000 XR 2023 Rider's Manual

If the values for the angle of
inclination are detected to be
implausible for a long period, a
substitute value is used for the
angle of inclination/the DTC
is turned off. In these cases, a
DTC fault is displayed. A self-
diagnosis must be completed
before the fault message can
be displayed.
Under the following un-
usual riding conditions,
BMW Motorrad Traction
Control may be deactivated
automatically.
Unusual riding conditions:
Riding on the rear wheel
(wheelie) for a longer period.
Rear wheel spinning in place
with front wheel brake en-
gaged (burn-out).
Warming up the engine on an
auxiliary stand in neutral or
with gear engaged.
ENGINE DRAG TORQUE
CONTROL
How does engine drag torque
control work?
The purpose of the engine drag
torque control is to safely pre-
vent unstable riding conditions
that are related to excess drag
torque at the rear wheel. De-
pending on the road condi-
tion and riding dynamics, ex-
cess drag torque can make the
slip at the rear wheel increase
severely and impede riding
stability. The dynamic engine
brake control limits slip at the
rear wheel to a safe, setpoint
slip that is dependent on the
mode and angle.
Causes of excess slip at the
rear wheel:
Riding in coasting overrun on
a road with low coefficient of
friction (e.g. wet leaves).
Hopping when shifting gears
down.
Hard brake onset in sporty
riding style.
Like the DTC traction control,
the dynamic engine brake con-
trol compares the wheel cir-
cumferential velocities of the
front and rear wheel. With the
aid of more information on
the angle, the dynamic engine
brake control can determine
the slip or the stability reserve
at the rear wheel.
If the slip exceeds the respec-
tive limit value, the engine
torque is increased by slightly
opening the throttle valves. The
slip is reduced, and the vehicle
is stabilized.
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