Turning the key to MAR the warning light on the dial turns on, but it should go off as soon as the engine is started.
If the 
warning light turns on when
the car is travelling (on certain versions together with the message on the display),
stop the engine immediately and contact a Fiat Dealership.
See also:
24. Door Ajar
This light will turn on to indicate that one or more doors or the trunk may be
ajar. ...
Warranty Information
See the Warranty Information Booklet, located on the DVD, for the terms and provisions
of FIAT Group Automobiles warranties applicable to this vehicle and market. ...
Diesel particulate filter clogged
(1.3 Multijet 85 HP and 1.9 Multijet 120 HP versions) (Amber)
diesel particulate filter is clogged and the driving conditions do not enable
to activate automatically the reclaiming procedure.
To ...