CITROËN C4 Handbook page 78

Access
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:
F press and hold the control until the
window opens fully,
F then pull the control immediately
and hold it until the window closes,
F 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.
76
Reinitialisation
After reconnecting the battery or a fault, you
must be reinitialise the operation of the electric
windows. For each of the control switches on
the driver's side control panel:
F pull the control until the window stops,
F release the control and pull it again until
the window closes fully,
F continue to hold the control for
approximately one second after the window
has closed,
F press the control to lower the window
automatically to the low position,
F 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.