CITROEN DS4 Owner's Handbook Manual page 118

Safety anti-pinch
When the window rises and meets an obstacle,
it stops and partially lowers again.
If the window cannot be closed
(for example, in the presence of ice),
once the window has lowered:
 press and hold the control until the
window opens fully,
 then pull the control immediately
and hold it until the window closes,
 continue to hold the control for
approximately one second after the
window has closed.
The safety anti-pinch function is not
operational during these operations.
Reinitialisation
If a window does not rise automatically,
its operation must be reinitialised:
 pull the control until the window stops,
 release the control and pull it again until
the window closes fully,
 continue to hold the control for
approximately one second after the
window has closed,
 press the control to lower the window
automatically to the low position,
 when the window has reached the low
position, press the control again for
approximately one second.
The safety anti-pinch function is not
operational during these operations.
Always remove the key from the ignition
when leaving the vehicle, even for a
short time.
If an obstacle is encountered during
operation of the electric windows,
you must reverse the movement of the
window. To do this, press the control
concerned.
When the driver operates the
passenger's electric window control,
they must ensure that nothing is
preventing the windows closing
correctly.
The driver must ensure that the
passengers use the electric windows
correctly.
Be aware of children when operating
the windows.