Volvo S 90, Owner'S Manual

Page: 381 / 548

STARTING AND DRIVING
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379
Stowing the ball holder
Compartment for the detachable trailer hitch
WARNING
When not in use, the detachable trailer hitch
should always be kept in its compartment in
the foam block under the cargo compartment
floor (see the illustration).
Related information
•
Driving with a trailer (p. 376)
•
Trailer Stability Assist (TSA) (p. 379)
Trailer Stability Assist (TSA)
Trailer Stability Assist is a system designed to
help stabilize a vehicle that is towing a trailer
when the vehicle and trailer have begun to sway
and is part of the Electronic Stability Control sys-
tem.
Function
A vehicle towing a trailer may begin to sway for
various reasons. Normally this only occurs at high
speeds but, for example, if the trailer is overloa-
ded or if the load is unevenly distributed in the
trailer, there is risk of swaying.
Swaying may be caused by factors such as:
•
The vehicle and trailer are hit by a sudden,
strong crosswind
•
The vehicle and trailer are traveling on an
uneven road surface or drive over a bump
•
Sudden movements of the steering wheel
Facts about TSA
•
The stability system symbol in the instrument
panel will flash when TSA is working
•
If the driver switches off the stability system's
Spin Control function, TSA will also be
switched off (but will be on again the next
time the engine is started)
•
TSA may not intervene when the vehicle and
trailer begin to sway if the driver tries to com-
pensate for the swaying motion by moving
the steering wheel rapidly
How TSA works
Once swaying has begun, it can be very difficult
to stop, which makes it difficult to control the
vehicle and trailer.
The TSA system continuously monitors the vehi-
cle's movements, particularly lateral movement. If
the system detects a tendency to sway, the
brakes are applied individually on the front
wheels, which has a stabilizing effect on the vehi-
cle and trailer. This is often enough to enable the
driver to regain control of the vehicle.
If this is not adequate to stop the swaying motion,
the brakes are applied to all of the wheels on the
vehicle and on the trailer if it is equipped with
brakes, and engine power is temporarily reduced.
As the swaying motion begins to decrease and
the vehicle-trailer have once again become sta-
ble, TSA will now stop regulating the brakes/
engine power and the driver regains control of
the vehicle.
TSA is deactivated if the driver deactivates
ESC
in the center display's menu system.
When the
ESC
symbol in the
instrument panel flashes, TSA
is active.