CITROEN C4 PICASSO Handbook page 196

Visibility
Operation of the rear foglamps is
inhibited with the tailgate open.
Opening the boot when these lamps are
on causes them and their indicator lamp
in the instrument panel to go off.
They do not come back on
automatically when the boot is closed:
they must be switched on again using
the control stalk.
194
In good or rainy weather, by both day
and night, the front foglamps and the
rear foglamps are prohibited. In these
situations, the power of their beams
may dazzle other drivers. They should
only be used in fog or falling snow.
In these weather conditions, you should
switch on the foglamps and dipped
beam headlamps manually, as the
sunshine sensor may detect sufficient
light.
Do not forget to switch off the front and
rear foglamps when they are no longer
necessary.
Switching off the lighting
when switching off the ignition
When the ignition is switched off, all of the
lamps switch off immediately, except for the
dipped beam headlamps if automatic guide-
me-home lighting is activated.
Switching on the lighting when
switching on the ignition
To reactivate the lighting control stalk, turn
the ring A to position "0" - lighting off, then
to the position of your choice.
If the lighting is switched on manually after
switching off the ignition, there is an audible
signal when a front door is opened to warn
the driver that they have forgotten to switch
off the vehicle's lighting, with the ignition off.
They switch off automatically after a period
which depends on the state of charge of the
battery (entry to energy economy mode).