The warning light on the dial turns on (on certain versions together with the message on the display) when one or more doors, the boot (indication fitted on some versions only) or the bonnet are not properly shut.
Symbols 
shown on the multifunction
display indicate incomplete left/right door closing.
With doors and boot open, if 4 km/h speed is exceeded the buzzer will sound (only for versions with reconfigurable multifunction display).
IMPORTANT On versions not fitted with electric door lock, no warning message will be displayed if door is not perfectly closed or is left open.
See also:
Engine Oil Filter
The engine oil filter should be replaced with a new filter at every engine oil
change.
Engine Oil Filter Selection
All of this manufacturer’s engines have a full-flow type disposable oil filter.
...
If an exterior light burns out
Alterations or repairs to the electric system not carried out correctly and
without taking into account the system specifications may cause failures and the
risk of fire.
See “If a bulb burns ou ...
Diesel fuel filter sensor failure
The warning light on the dial comes on (on certain versions together with the
message on the display) when dieel fuel filter sensor failure is detected. Contact
Fiat Dealership as soon as poss ...