light BMW X5 2002 E53 DSC System Workshop Manual

10
ELECTRONIC BRAKE PROPORTIONING (EBV)
Electronic brake proportioning allows the DSC system to adjust the braking force to the rear
wheels based on the vehicle’s loading to maximize the braking force at all wheels.
The DSC control module monitors the wheel speed sensors inputs when the brakes are
applied, for activation of this feature. The control module compares the speed at which the
front and rear axles are slowing down to determine vehicle loading.
If the rear axle is slowing at a similar rate to the front, it indicates that the vehicle is loaded
and more braking force can be applied to the rear calipers to slow and stop the vehicle.
If the decel rate of the rear axle is much less than the front, the vehicle is lightly loaded and
less force can be applied to the rear. If the same force were applied, then the vehicle could
become unstable.
OPERATION
The values for the decel rate are programmed in the DSC control module. Equal force will
be applied to the front and rear axles until the threshold values are exceeded. At this point,
the DSC control module will cycle the inlet valves at the rear calipers to reduce the braking
force on the rear axle.