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177n
The transmission of power to the four
drive wheels is provided permanently
through a transfer box. The distribution
of torque between the front and rear
axles is 38 % to 62%.
Traditional differential locks at the front
and rear axles and in the transfer box
are not required. Their function is taken
over by automatic braking intervention
at all four wheels. These traction inter-
ventions are governed by Automatic
Differential Brake (ADB), a sub-function
of DSC.
If a wheel tends to slip, it is braked
automatically by ADB until it once again
gains traction, and drive force can be
transmitted to that wheel. In addition,
the drive force is distributed to the
remaining wheels during this system
530us133
intervention. Engine output is also re-
duced if necessary.
When the DSC is deactivated, the ADB
traction intervention is set for the maxi-
mum drive force. However, the engine
intervention and the stability controls
are no longer available. For this reason,
DSC should only be deactivated in the
exceptional circumstances described
on page 83.
The BMW X5 is a vehicle for all types of
roads. The permanent four-wheel drive
provides a significant degree of vehicle
stability and tractive power under all
road conditions. It assists in critical sit-
uations such as driving in extreme win-
ter conditions or on bad roads.
Precision sensors monitor the wheel
speeds, the steering angle, lateral
acceleration, brake pressure and the
movement of the vehicle around its
vertical axis.
If differences in wheel speeds occur,
the system recognizes the danger of
wheelspin and reduces the engine's
drive torque. If necessary, the system
also responds with additional braking
intervention at all four wheels.
In addition, DSC permanently monitors
the vehicle's current operating condi-
tion and compares it with an ideal con-
dition that is calculated from the sensor
signals. If discrepancies from this ideal
condition (understeering or oversteer-
ing, for example) occur, DSC stabilizes
the vehicle in fractions of a second by
reducing engine power output and with
the assistance of braking intervention at
individual wheels. Dangerous skids are
thus prevented from the very beginning.
You may need some time to become
accustomed to this system intervention.
However, it provides optimum drive
force and vehicle stability.
The braking intervention may be ac-
companied by certain sounds specific
to the system.
Four-wheel drive DSC
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