In your manual, skip the protosounds section. I don't think you have it. The manual is for both models!
So go to page 25.
do the reset for unlocking engine (direction).
I followed your instructions and the whistle lever does not produce a sound BUT I did get it to go back and forth. There was no whistle or horn but the engine will now respond to the direction button. I will probably go ahead with a TMCC chip depending on what my son wants to do.