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:
ESC Activation/Malfunction Indicator Light AndESC OFF Indicator Light
The ESC Activation/Malfunction Indicator Light in the instrument cluster will
come on when the ignition switch is turned to the MAR (ACC/ON/RUN) position for
four seconds. If the ESC Activation/ ...
Boot light
To change the bulb, proceed as follows:
❒ remove the lens (A) as shown by the arrow;
❒ lift protection (B) and remove the bulb (clipped in).
...
Failure warnings
In the event of failure, the ESP system is automatically disconnected and the
instrument panel warning light á will come on with fixed light together with the
message on the reconfigurable ...