CITROËN DS5 Owner's Handbook Manual page 176

Deactivation
Only the passenger's front airbag can be
deactivated:
with the ignition off, insert the key in the f
passenger airbag deactivation switch,
turn it to the "OFF" position,
then, remove the key keeping the switch in
the new position.
According to version, this warning lamp
comes on either in the instrument panel
or in the seat belt and passenger's front
airbag warning lamp display when the ignition is on
and until the airbag is reactivated.
To assure the safety of your child,
the passenger's front airbag must be
deactivated when you install a "rear
facing" child seat on the front passenger
seat.
Otherwise, the child would risk being
seriously injured or killed if the airbag
were deployed.
Reactivation
When you remove the child seat, with
the ignition off, turn the switch to the f
position to reactivate the airbag and so assure
the safety of your front passenger in the event
of an impact.
With the ignition on, this warning
lamp comes on in the seat belt and
passenger's front airbag warning
lamp display for approximately
one minute, if the passenger's front
airbag is activated.
Operating fault
If this warning lamp comes on in the
instrument panel, accompanied by an
audible warning and a message in the
instrument panel screen, contact a
CITROËN dealer or a qualified workshop to have
the system checked. The airbags may no longer
be deployed in the event of a serious impact.
If this warning lamp flashes, contact
a CITROËN dealer or a qualified
workshop. The passenger's front
"ON"
airbag may no longer be deployed in
the event of a serious impact.
If even one of the two airbag warning
lamps comes on continuously, do
not install a child seat on the front
passenger seat.
Have it checked by a CITROËN dealer
or qualified workshop.