HANDBRAKE ON (red)
Turning the ignition key to MAR the warning light turns on, but it should go off after few seconds.
Low brake fluid level
The warning light turns on when the level of the brake fluid in the reservoir falls below the minimum level, due to possible leak in the circuit.
On certain versions the dedicated message is displayed.
If the warning light 
turns on
when traveling (on certain versions together with the message on the display) stop
the vehicle immediately and contact Fiat Dealership.
Handbrake on
The warning light turns on when the handbrake is on.
On certain versions, if the vehicle is moving the buzzer will also sound.
IMPORTANT If the warning light turns on when traveling, check that the handbrake is not engaged.
See also:
How to start diesel versions
1) Ensure that the handbrake is up.
2) Put the gear lever into neutral.
3) Turn the ignition key to MAR. Instrument panel warning lightswill
come on.
4) Wait for warning lights
to turn off.
5 ...
Fluids and lubricants
RECOMMENDED PRODUCTS AND THEIR SPECIFICATIONS
For diesel engines, in emergency cases where genuine products are not available,
lubricants with min. performance ACEA C2 are accepted. If this is th ...
Sentry Key
The Sentry Key Immobilizer System prevents unauthorized vehicle operation by
disabling the engine. The system does not need to be armed or activated. Operation
is automatic, regardless of whether ...