Volvo XC90 Owner's Manual page 405

Hill Start Assist
The function for assisting when starting the
4
vehicle on inclines (HSA ) helps prevent the
vehicle from rolling backward when starting
on an uphill gradient. When backing up a hill,
HSA helps prevent the vehicle from rolling
forward.
The function retains pressure from the brake
pedal in the brake system for several seconds
after the brake pedal has been released.
This temporary braking effect is released after
a few seconds or when the driver begins driv-
ing.
Hill Start Assist is available even when the
Auto-hold brake function is switched off.
Related information
Auto-hold brakes (p. 401)
•
Brakes (p. 395)
•
4 Hill Start Assist
Braking assist after a collision
In a collision in which the activation level is
reached for the pyrotechnic seat belt tension-
ers or airbags, or if a collision with a large ani-
mal is detected, the vehicle's brakes will be
automatically activated. This function is
intended to help prevent or reduce the effects
of any subsequent collision.
After a serious collision, it may no longer be
possible to control and steer the vehicle. In
order to avoid or mitigate a possible further
collision with a vehicle or an object in the vehi-
cle's path, the brake assist system is activated
automatically to help stop the vehicle safely.
If braking is not appropriate, e.g. if there is a
risk of being hit by passing traffic, the driver
can override the system by depressing the
accelerator pedal.
This function assumes that the brake system
is intact after a collision.
Related information
Rear Collision Warning* (p. 337)
•
BLIS* (p. 338)
•
Brake functions (p. 395)
•
STARTING AND DRIVING
Transmission
The transmission is part of the vehicle's drive-
line (power transmission) between the engine
and the drive wheels. The function of the
transmission is to change gears depending
on speed and power needs.
The vehicle has an 8-speed automatic trans-
mission. The number of gears allows the
engine's torque and power band to be effec-
tively utilized. Two of the gears are overdrive
gears that save fuel when driving at a constant
engine speed. Manual shifting is also possible.
The instrument panel shows the gear currently
in use.
Related information
Automatic transmission (p. 404)
•
* Option/accessory.
403