CITROËN C4 Picasso Owner's Handbook Manual page 242

Safety
Child seat in the front
"Rearward facing"
When a "rearward-facing" child seat is
installed on the front passenger seat, adjust
the vehicle seat to the midway longitudinal
position, the lowest height position, backrest
straightened. Then pull the height control lever
11 times.
The passenger's airbag must be deactivated.
Otherwise, the child risks being seriously
injured or killed if the airbag is deployed.
242
"Forward facing"
When a "rearward-facing" child seat is
installed on the front passenger seat, adjust
the vehicle seat to the midway longitudinal
position, the lowest height position, backrest
straightened. Then pull the height control lever
11 times. Leave the passenger's airbag active.
Ensure that the seat belt is properly
tightened.
For child seats with a stay, ensure
that this is in firm and steady contact
with the floor. If necessary, adjust the
passenger's seat.
Passenger seat in the midway longitudinal
position, the lowest height position, then
the height control lever pulled 11 times.