CITROËN DS4 Owner's Handbook Manual page 53

Deactivation indicator lamps
If one of the following indicator lamps comes on, this confirms that the corresponding system has been switched off intentionally.
This is may be accompanied by an audible signal and a message on the multifunction screen.
Warning lamp is on
Passenger's fixed in the instrument
airbag system panel and/or seat belt
and front passenger's
airbag warning lamps
display.
ESP/ASR fixed.
Cause
The control switch, located in the
glove box, is set to the OFF position.
The passenger's front airbag is
deactivated.
The button, located at the bottom
left of the dashboard, is pressed. Its
indicator lamp is on.
The ESP/ASR is deactivated.
ESP: electronic stability programme.
ASR: anti-slip regulation.
Action/Observations
Set the control to the "ON" position to activate
the passenger's front airbag.
In this case, do not fit a child seat in the rear-facing
position.
Press the button to activate the ESP/ASR. Its indicator
lamp goes off.
The ESP/ASR system is activated automatically when
the vehicle is started.
If deactivated, the system is reactivated automatically
from around 30 mph (50 km/h).
51
Monitoring