Volvo V70 Owner's Manual page 318

07 During your journey
Driving with a trailer
Push the protective cover until it snaps
tight.
Trailer Stability Assist - TSA*
The TSA system (Trailer Stability Assist) serves
to stabilise the car and trailer combination if it
begins to snake.
The TSA function is part of the DSTC system
(Dynamic Stability and Traction Control), see
page 150.
Function
The snaking phenomenon can occur with any
car/trailer combination. Normally, snaking
07
occurs at extremely high speeds. But, there is
a risk of it occurring at lower speeds
(70-90 km/h) if the trailer is overloaded or the
load is improperly distributed, e.g. too far back.
In order for snaking to occur, there must be a
triggering factor, e.g.:
*
316
Option/accessory, for more information, see Introduction.
•
Car with trailer subjected to a sudden and
powerful side wind.
•
Car with trailer drives on an uneven road
surface or in a pothole.
•
Sweeping steering wheel movements.
Operation
If snaking has started, it could be difficult or
even impossible to suppress. This makes the
car/trailer combination difficult to control and
there is a risk that you could, for example, end
up in the wrong lane or leave the carriageway.
TSA system continually monitors car move-
ments, particularly lateral movements. If snak-
ing is detected, the front wheels are individually
braked. This serves to stabilise the car/trailer
combination. This is often enough to help the
driver regain control of the car.
If snaking is not eliminated the first time the
TSA system comes into action, the car/trailer
combination is braked with all wheels and
engine power is reduced. Once snaking has
been gradually suppressed and the car/trailer
combination is once again stable, the TSA sys-
tem stops regulating and the driver once again
has full control of the car.
Miscellaneous
The TSA system can engage within the speed
interval 60 to 160 km/h.
NOTE
TSA function is switched off if the driver
selects Sport mode, see page 150.
TSA may fail to engage if the driver uses severe
steering wheel movements to try to rectify the
snaking because in such a situation the TSA
system cannot determine whether it is the
trailer or the driver that is causing the snaking.
The DSTC symbol in the combined
instrument panel flashes when the
TSA is working.