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 temperatureRemoval of the water pump
Note
For clarity, the figures show the engine removed from the frame.
Loosen and remove the water pump cover (12) fixing screws (13) to the
generator cover (16).
Remove the water pump cover (12).
Clean the pump housing of any scale. Check the bearings wear by turning the
impeller s ...
Tips on how to select the sensitivity level
Warning
The 8 level settings of the dtc were calibrated using tyres of the
same make, model and size as those originally fitted to
the motorcycle.
The use of tyres of different size to the original tyres may alter the operating
characteristics of the system.
In the case of minor differen ...
Hands free key (hf) not recognised
The activation of this (amber yellow) "warning" indicates that the hands free
system does not detect the active key (1,
fig.62) Near the vehicle.
Note
Check that the active key (a) is near the vehicle (and has not been lost)
or that it works properly.
...