Fault codes
Dds: horn diagnosis -> short circuit to ground (s.C. Gnd).
Dashboard: the error "claxon" (horn) is shown on the service display. The eobd warning light activates.
Wiring diagram

Db dashboard connection, s horn button. 5 Blue/white - b/w, 1 red/blue - r/b, db 19 purple/black - v/bk.
Location of connections and components

Location of left hand handlebar switchgear set connection.

Location of horn with relative connection.

Pin numbering for wiring harness side dashboard connector.
Note
Check integrity of electric circuit - short-circuit to vdc = with dashboard on, using a voltmeter, a voltage is measured between the wire tested and ground.
Check integrity of electric circuit - short-circuit to ground = with the battery cables disconnected, using an ohmmeter, continuity is detected between the wire tested and ground.
Check integrity of electric circuit - open circuit = with the battery cables disconnected, using an ohmmeter, no continuity is detected between the two ends of the wire tested.
Low beam lights not working
Turn indicators not workingRemoval of the licence plate holder
Disconnect connector (5) of the number plate holder wiring from the main one.
Release the number plate holder light cable from the ties and the cable grommets
as indicated in sect- 7 - 6, flexible
wiring/hoses positioning, since the cable is together with the rear abs sensor
cable.
...
Removal of the starter motor idler gear
Slide the gear pin (21) complete with the gear (19) and washer (20).
Warning
Pay attention to the washer (20) since it may fall inside the
crankcase half.
At this point, it is possible to remove the starter motor as described in
sect. 6 - 3, Starter motor. ...
Tips for use on the road
Activate the dtc, select level 8 and ride the motorcycle in
your usual style; if the level of dtc intervention seems
excessive, try reducing the setting to levels 7, 6, etc., Until
you find the level that suits you best.
If changes in the grip conditions and/or circuit characteristics
and/or ...