DAF VSC Service Manual
DAF - Vehicle StAbility control
KeepS you on the roAD
What is Vehicle Stability Control?
Vehicle Stability Control (VSC) is an electronic active safety
system that helps the driver to stay in control of his vehicle
during a critical manoeuvre, such as swerving to avoid an
obstacle or strong steering in an unanticipated tight corner.
VSC strongly reduces the risk of a sudden roll-over that
particularly hangs over tankers and vehicles with a high
centre of gravity, during cornering or quick lane change
manoeuvres. Secondly, VSC significantly reduces the risk of
jack-knifing.
VSC continuously monitors the driver’s steering input against
the direction of the vehicle. When they do not match, VSC will
automatically reduce engine power and if necessary actuate
the brakes at one or more wheels for short periods of time.
Why would I specify VSC on my vehicle?
VSC can prevent many types of crashes, but is especially
effective in preventing single vehicle crashes that result from a
loss of control.
VSC can save the life of your driver and that of other road-
users. This by itself should be enough reason to have VSC
on your truck.
But there is more. A badly crashed vehicle in the news,
with the name of your own firm or that of your customer
clearly legible on it, will not contribute to a sound company
reputation.
Consequential losses may result in various areas:
• loss of goods, damaged goods, late delivery
• vehicle recovery and vehicle damage
• traffic jams and damage to the road
• environmental consequences
1 | DAF - Vehicle StAbility control
DAF - Vehicle StAbility control
KeepS you on the roAD
How does VSC work?
The VSC system uses several sensors to determine
what the driver wants (steering wheel angle sensor)
and to measure how the vehicle reacts on the
driver’s input (yaw rate sensor, lateral acceleration
sensor and wheel speed sensors).
If a potential loss of vehicle control is detected,
VSC automatically cuts engine throttle and
if necessary applies brake pressure to the
appropriate wheel(s), to help bring the vehicle back
in line with the driver’s intended path.
Lateral instability
Lateral instability may result from slippery road
conditions or excessive speed in a curve, and
from pulling the vehicle back on the road from
a soft shoulder.
In case of understeer the front of the vehicle slides
to the outside edge of the curve and if uncorrected,
will leave the road. VSC will apply the brakes at the
curve-inside wheels to bring the tractor back on its
intended path.
In case of oversteer the driven axle slides to the
outside edge, causing the front of the vehicle to
move to the inside edge of the curve. Excessive
oversteer may result in jack-knifing. VSC will correct
the oversteer tendency by strongly applying the
trailer brakes (streching the combination) and
by braking of the appropriate tractor wheels
(to support the steering wheels).
Vertical instability
Vehicle roll-over may be induced by high speed
cornering on motorway exits, but can also occur at
lower speeds, as a result of too fast or too strong
steering inputs from the driver. The latter may occur
during evasive quick lane change manoeuvres. In
case of an impending roll-over VSC will apply brakes
and reduce engine torque to slow the combination
down, back to safe operating conditions.
2 | DAF - Vehicle StAbility control
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