I don't have my Ultimate yet but I understand on the Ultimate the light number 2 will light up as a cornering light when making a turn so I presume it comes on with the operation of the turn signal.
More than turn signal operated...
Cornering lamp (if equipped)
While driving a corner, for greater
visibility and safety, either the left or
right side Cornering lamp will turn on
automatically. The cornering lamp
will turn on when one of the following
conditions occur.
• Vehicle speed is less than 10 km/h
(6 mph) and steering wheel angle is
turned approximately 80 degrees with
the low beam on.
• Vehicle speed is between 10 km/h
(6 mph) to 90 km/h (56 mph) and
steering wheel angle is turned
approximately 35 degrees with the
low beam on.
• When the vehicle is in reverse with
one of the conditions above satisfied,
the light opposite to the direction the
steering wheel is turned will turn on.