Stability System - Volvo XC90 Owner's Manual

Starting and driving

Stability system

–
DSTC Dynamic
Stability and Traction
Control
The Dynamic Stability and Traction Control
system (DSTC) comprises several different
functions:
•
The Traction Control function transfers
power from the spinning drive wheel to
the drive wheel which has grip by braking
the spinning drive wheel. To increase
forward traction in this situation, you may
need to depress the accelerator more than
usual. A pulsing sound is heard when
Traction Control is working. This is
completely normal. The TC function is
most active at low speeds. It cannot be
switched off.
•
The Stability Control function is designed
to prevent the drive wheels from slipping
during acceleration by lowering
engine torque. This improves navigation
and road safety on slippery surfaces.
Under certain conditions, such as when
driving with snow chains or in deep snow
or sand, it may be beneficial to switch off
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the SC function to increase traction. This
is done using the DSTC button.
•
The Active Yaw Control function
automatically brakes one or more of the
wheels to stabilise the car in the event of
a skid. If you were to depress the brake
pedal in this situation, it would feel more
rigid than usual and a pulsing sound
would be heard. For reasons of safety, the
AYC function is always active and
cannot be switched off.
•
The Roll Stability Control function
automatically brakes one or more wheels.
This stabilises the car laterally so as to
minimise the risk of overturning due to a
skid or the like. If you were to depress the
brake pedal in this situation, it would feel
more rigid and a pulsing sound would be
heard. For reasons of safety, the RSC
function is always active and cannot be
switched off.
DSTC button
The DSTC button in the centre console is used
to reduce or reactivate the DSTC system.
Reducing the system means that the Stability
Control (SC) and Active Yaw Control (AYC)
functions are reduced. Other functions are not
affected.
When the LED in the button is lit, the DSTC
system is activated (assuming there is no fault).
For reasons of safety, the button must
be depressed for at least one half second to
reduce the DSTC system function.
The LED in the button is extinguished
and "DSTC SPIN CONTROL OFF" is shown in
the display.
The DSTC system is automatically reactivated
each time the engine is started.
The warning symbol flashes when...
• The SC function works to keep the car's
drive wheels from slipping.
• The TC function works to improve the
car's traction.
• The AYC function works to keep the car
from skidding.
• The RSC function works to prevent the
car from overturning.