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 temperatureOperating principle and characteristics of the ride-by-wire system
The engine control system of the diavel uses a ride-by-wire system with
motorised throttle valves. This eliminates all
direct connection with metal cables between the throttle grip and the throttle
valves themselves. Cables are used to
rotate the aps potentiometer, which generates an electric ...
Entering pin code function for vehicle release
This function turns on the motorcycle "temporarily" in the
case of hf (hands free) system "malfunctions".
To activate the function, press the "emergency" hands free
button (7, fig. 87) If the motorcycle cannot be turned on using
the normal starter button.
After ...
Reassembling the water radiator unit
The procedure is the same for both radiators.
Check the presence of clips (1) at the positions of the external coolant
radiator cover (23).
If removed, fit the front turn indicator (32) on the cover (23) and tighten the
screws (27) to 2 nm +/- 10% (sect. 3 - 3,
Frame torque settings).
No ...