The activation of this (amber yellow) "warning" indicates that the hands free system has detected that the battery that permits the active key (1, fig. 62) To communicate and turn the vehicle on is almost discharged.
Note
In this case, ducati recommends replacing the battery as soon as possible as described in the paragraph "replacing the active key battery" (page 88).

Hands free key (hf) not recognised
High engine coolant temperatureTubeless tyres
Front tyre pressure:
2.50 Bar (rider only) - 2.6 Bar (with passenger and/or bags)
rear tyre pressure:
2.50 Bar (rider only) - 2.6 Bar (with passenger and/or bags)
as tyre pressures are affected by changes in temperature
and altitude; check and adjust them whenever you are riding
in areas where ...
Ducati limited warranty on emission control system
Ducati north america, inc., 10443 Bandley drive cupertino,
california, 95014 warrants that each new 1998 and later
ducati motorcycle, that includes as standard equipment a
headlight, tail-light and stoplight, and is street legal:
a) is designed, built and equipped so as to conform at the
time o ...
Brakes
Separate-action anti-lock brake system operated by hall-type
sensors mounted to each wheel, with phonic wheel
detection: abs can be disabled.
Front
Semi-floating drilled dual disc.
Braking material:
steel.
Carrier material:
aluminium.
Disc diameter:
320 mm.
Hydraulically operated ...