Turning the ignition key to MAR the warning light on the dial turns on, but it should go off after few seconds. The warning light turns on when the handbrake is on.
IMPORTANT If the warning light 
turns
on when travelling, check that the handbrake is not engaged.
With handbrake engaged, if 4 km/h speed is exceeded the buzzer will sound (only for versions with reconfigurable multifunction display).
WARNING
If the warning light 
turns on when
travelling (on certain versions together with the message on the display) stop the
car immediately and contact Fiat Dealership.
See also:
Fluid Capacities
...
Periodic Safety Checks You Should Make OutsideThe Vehicle
Tires
Examine tires for excessive tread wear and uneven wear patterns. Check for stones,
nails, glass, or other objects lodged in the tread or sidewall. Inspect the tread
for cuts and cracks. Ins ...
To Resume Speed
To resume a previously set speed, push the RES (+) button and release. Resume
can be used at any speed above 20 mph (32 km/h). ...