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 temperatureIndicator speed avg - average speed
This function shows the average speed of the motorcycle.
The calculation is made considering the distance and time
travelled since the last trip 1 reset. When trip 1 is reset, the
value is set to zero and the first available value is shown on
the display 10 seconds after the reset. Dashes &quo ...
Recharging the battery
Examine the label on the battery showing the check intervals in order to
determine when to test the voltage.
Charge the battery if the open circuit voltage is lower than 12.8 V. Leaving
the battery discharged for more than one
month could damage it. Check the battery charge with a voltmete ...
Engine temperature sensor
Introduction
The engine control system on the diavel uses a sensor that measures the
temperature of the coolant (engine
temperature). This sensor has a resistance of ntc type (negative temperature
coefficient), that reduces its own value
when the temperature increases. The engine temperature ...