Trailer Stability Assist - Volvo XC40 TWIN ENGINE 2019 Owner's Manual

Related information
Trailer stability assist* (p. 465)
•
Checking trailer lamps (p. 466)
•
Towing capacity and towball load
•
(p. 638)
Overheating in the engine and drive sys-
•
tem (p. 457)
Adverse driving conditions for engine oil
•
(p. 642)
Extendable and retractable towbar*
•
(p. 461)
10

Trailer Stability Assist

11 Electronic Stability Control
Trailer stability assist*
The function of trailer stability assist (TSA
is to stabilise cars towing trailers in situations
where they begin snaking. The function is
included in the stability system ESC
Reasons for snaking
The snaking phenomenon can occur with any
car/trailer combination. Snaking normally
occurs at high speeds. However, there is a risk
of it occurring at lower speeds if the trailer is
overloaded or the load is improperly distrib-
uted, e.g. too far back.
In order for snaking to occur, there must be a
triggering factor, e.g.:
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.
•
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.
Trailer stability assist function
The trailer stability assist function continually
monitors the car's movements, particularly lat-
eral movements. If snaking is detected, the
front wheels are individually braked. This
10 )
serves to stabilise the car/trailer combination.
This is often enough to help the driver regain
control of the car.
11 .
If snaking is not eliminated the first time that
trailer stability assist intervenes, 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 stable once again, the system
stops regulating and the driver once again has
full control of the car.
NOTE
The stability function is deactivated if the
driver selects Sport mode by deactivating
ESC via the menu system in the centre
display.
Trailer stability assist may fail to intervene if
the driver uses severe steering wheel move-
ments to try to rectify the snaking because in
such a situation the system cannot determine
whether it is the trailer or the driver causing
the snaking.
STARTING AND DRIVING
}}
465
* Option/accessory.