Vauxhall Corsa Owner's Manual page 82

The curtain airbag system will be triggered:
z depending on the severity of the
accident,
z depending on the type of impact,
z within the range shown in the illustration
on the centre door pillar of the driver's or
front passenger side,
z together with the side airbag system,
z irrespective of seat occupancy
recognition,
z independently of the front airbag
system.
80
When triggered, the curtain airbag inflates
in milliseconds to form a safety cushion in
the head area on the side of the vehicle
affected. This substantially reduces the risk
of injury to the head in the event of a side-
on collision.
There must be no objects in the area in
which the airbag inflates. Do not place
the hands or arms on the covers of the
airbag systems. Important information –
see page 84.
The three-point seat belt must always be
correctly fitted – see page 74.
The curtain airbags will not be triggered in
the event of
z the ignition is switched off,
z frontal collisions,
z accidents in which the vehicle overturns,
z collisions involving a rear impact,
z collisions involving a side impact outside
the passenger cell.