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:
Installation of electric / electronic devices
Electric/electronic devices installed after buying the car or in aftermarket
shall bear the and marking:
Fiat Auto S.p.A. authorizes the installation of transceivers provided that installation
...
Useful advice for lengthening the life of your battery
To avoid draining your battery and lengthen its life, observe the following indications:
– when you park the vehicle, ensure the doors, tailgate and bonnet are closed
properly;
– the ceiling light ...
Air Conditioning (A/C)
The Air Conditioning (A/C) button allows the operator to manually activate or
deactivate the air conditioning system. When in A/C mode with the ATC set to a cool
temperature, dehumidified air flow ...