CITROEN Grand C4 PICASSO Owner's Handbook Manual page 142

Driving
Ignition on without
starting
With the electronic key in the reader or the
Keyless Entry and Starting key inside the
vehicle, pressing the "START/STOP" button,
with no action on the pedals , allows the
ignition to be switched on.
Press the "START/STOP" button,
the instrument panel comes on
but the engine does not start.
Press the button again to switch off the
ignition and so allow the vehicle to be
locked.
With the ignition on, the system goes
into energy economy mode when
necessary to maintain the state of
charge of the battery.
140
Anti-theft protection
Electronic engine immobiliser
The keys contain an electronic chip which has
a secret code. When the ignition is switched
on, this code must be recognised in order for
starting to be possible.
This electronic engine immobiliser locks the
engine management system a few minutes
after the ignition is switched off and prevents
starting of the engine by anyone who does not
have the key.
In the event of a malfunction, you are informed
by a message in the instrument panel screen.
In this case, your vehicle does not start; contact
a CITROËN dealer as soon as possible.