CITROEN DS4 Owner's Handbook Manual page 92

Additional adjustments
Head restraint height and angle
adjustment
To raise a head restraint, pull it upwards.
To remove the head restraint, press the
lug A and pull the head restraint upwards.
To put the head restraint back in place,
engage the head restraint stems in the
openings keeping them in line with the seat
back.
To lower the head restraint, press the lug A
and the head restraint at the same time.
To adjust the angle of the head restraint, tilt
its lower part forwards or rearwards.
The head restraint is fitted with a frame
with notches which prevents it from
lowering; this is a safety device in case
of impact.
The adjustment is correct when the
upper edge of the head restraint is
level with the top of the head.
Never drive with the head restraints
removed; they must be in place and
adjusted correctly.
Heated seats control
With the engine running, the front seats can be
heated separately.
Use the adjustment dial, placed on the side
of each front seat, to switch on and select
the level of heating required:
0: Off.
1 : Low.
2 : Medium.
3 : High.