CITROEN DS3 Handbook page 158

deactivation
In extremely severe conditions (deep snow,
mud...), when it is not possible to move off, it
may be useful to temporarily deactivate the
systems, so that the wheels can spin freely and
regain grip.
F Press this button, located on the left below
the steering wheel.
Illumination of the lamp in the button indicates
that the systems are deactivated.
Reactivation
These systems are reactivated automatically
each time the ignition is switched back on
or from 30 mph (50 km/h) except 1.6 litre
(THP 150, THP 155 and THP 160) and
RACING petrol engines.
F Press this button again to reactivate them
manually.
Operating fault
Illumination of this warning lamp in the
instrument panel and the lamp in the
button, accompanied by an audible
signal and a message, this indicates a
malfunction of these systems.
Have it checked by a CITROËN dealer or a
qualified workshop.
The DSC/ASR systems offer
exceptional safety in normal driving, but
this should not encourage the driver to
take extra risks or drive at high speed.
The correct functioning of these
systems depends on observation of the
manufacturer's recommendations on:
- wheels (tyres and rims),
- braking components,
- electronic components,
- assembly and repair procedures.
After an impact, have these systems
checked by a CITROËN dealer or a
qualified workshop.