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 tail light
Disconnect the connectors (a) and (b) of the tail lights (1) and (13).
Loosen the screws (4) and slide the tail lights (1) and (13) to the rear side;
recover the four spacers (3) and the washers
(14).
...
Flexible wiring/hoses positioning
The routing of the abs wiring has been optimised to ensure the minimum
obstruction.
Each section is designed to prevent interference with parts that might damage
wires or cause operating failures when
riding.
Table a
Table b
Table c
...
Battery voltage indicator (battery)
This function describes the battery voltage indicator.
To access the function it is necessary to view the ""setting" menu", using
buttons (1) "s" or (2) "t" select the "battery"
function and press the reset button (3) to confirm.
The information will be displayed as follows:
if battery vol ...