Help yamaha yz450f 2017,high idle ,failure

Apr 22, 2019
Hello. This is a Yamaha yz450F 2017 motorcycle, 125 motorhour.The problem is that when the engine is hot,the coolant temperature reaches temperatures above 100 ° C ,
idle speed remains at 4000 rpm and does not decrease . But when I turn off the engine,
I'll start again ,The idling speed is maintained at 1900 rpm, but when I add gas, again they hold at 4000rpm.That's interesting,that the bike does it only then,if the coolant reaches temperatures above 100 C.I checked everything, valve clearance,coolant sensor,air pressure sensor, throttle position sensor, throttle body joint, all values were in norm, as yamaha service manual writes.
But it's also interesting,when I press the motor engine stop switch, but so that the engine does not go out, the idle speed will be normal again.Ale akonáhle pridám plyn,the idle speed is kept back at 4000 rpm.That it would be a mistake in the engine control unit? But how to check it?It's not cheap spare part.The Yamaha Power Tuner does not display an error code .Please help me. Video:
Thank you