CITROEN DS5 Owner's Handbook Manual page 152

Rear wiper
If a significant accumulation of snow
or ice is present, or when using a
bicycle carrier on the boot, deactivate
the automatic rear wiper via the
configuration menu.
Rear wiper selection ring:
park,
intermittent wipe,
wash-wipe (set duration).
Reverse gear
When reverse gear is engaged, the rear wiper
will come into operation if the windscreen
wipers are operating.
Programming
The function is activated or
deactivated via the configuration
menu.
This function is activated by default.
Windscreen and headlamp
wash
Pull the windscreen wiper stalk towards
you. The windscreen wash then the
windscreen wipers operate for a fixed
period.
The headlamp washers only operate when
the dipped beam headlamps are on.