CITROEN DS5 Owner's Handbook Manual page 124

Stop & Start
The Stop & Start system puts the engine temporarily into standby - STOP mode - during stops in the traffic (red lights, traffic jams, or other...). The
engine restarts automatically - START mode - as soon as you want to move off. The restart takes place instantly, quickly and silently.
Perfect for urban use, the Stop & Start system reduces fuel consumption and exhaust emissions as well as the noise level when stationary.
Operation
Going into engine STOP mode
The "ECO" warning lamp comes on
in the instrument panel and the engine
goes into standby automatically:
- with the electronic gearbox system, at
speeds below 5 mph (8 km/h), press the brake
pedal or put the gear lever in position N.
If your vehicle is fitted with the system, a time
counter calculates the sum of the periods in
STOP mode during a journey. It resets itself to
zero every time the ignition is switched on with
the START/STOP button.
For your comfort, during parking
maoeuvres, STOP mode is not available
for a few seconds after coming out of
reverse gear.
STOP mode does not affect the
functionality of the vehicle, such as for
example, braking, power steering...
Never refuel with the engine in STOP
mode; you must switch off the ignition
with the START/STOP button.
Special cases: STOP mode not
available
STOP mode is not invoked when:
- the driver's door is open,
- the driver's seat belt is not fastened,
- the vehicle has not exceeded 6 mph
(10 km/h) since the last engine start using
the START/STOP button,
- the electric parking brake is applied or
being applied,
- the engine is needed to maintain a
comfortable temperature in the passenger
compartment,
- demisting is active,
- some special conditions (battery charge,
engine temperature, braking assistance,
ambient temperature...) where the engine is
needed to assure control of a system.
In this case, the "ECO" warning lamp
flashes for a few seconds then goes
off.
This operation is perfectly normal.