CITROEN DS3 Handbook page 154

Reinitialisation of the system is done in the vehicle configuration menu, with the vehicle stationary and the ignition on.
Monochrome screen A
F Press the MEnU button for access to the
main menu.
F Press the "5" or "6" button to select
the Veh config menu, then confirm by
pressing the OK button.
F Press the "5" or "6" button to select the
"Reinit inflat", menu, then confirm by
pressing the OK button.
A message is displayed to confirm the
instruction.
F Confirm by pressing the OK button.
Monochrome screen C
F Press the MEnU button for access to the
main menu.
F Press the "5" or "6" button to select the
"Personalisation-configuration" menu,
then confirm by pressing the OK button.
F Press the "5" or "6" button to select the
"define vehicle parameters" menu, then
confirm by pressing the OK button.
F Press the "5" or "6" button to select
the "Tyre pressures" menu, then the
"Reinitialisation" menu, then confirming
by pressing the OK button.
A message confirms the reinitialisation.