The activation of this (amber yellow) "warning" indicates that the engine coolant temperature is high.
It is activated when the temperature reaches 121C (250f).
Note
In this case, stop the vehicle and switch the engine off immediately; make sure that the fans are working.

Low hands free key (hf) battery level
Steering release error - steering still lockedHeadlight control
This function allows you to reduce current consumption from
the battery, by automatically managing headlight switchingoff.
At key-on, the high beam and low beam lights are off.
When the engine is started, the low beam lights turn on
automatically; from this moment, "normal" operati ...
Removal of the throttle twistgrip
Peel back the rubber sleeve (a) protecting the throttle control cables.
Undo the screws (b) of the throttle grip (6) and open the command.
Disconnect the throttle grip cables (10) by unhooking the cable ends (c) from
their seats.
Remove the throttle twistgrip (6) from the handlebar.
...
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 ...