Again - ventilation of 400/500 Titanium PowerBook.

It seems that this Book has no readable sensors, so how is that done ?
Florian Zschocke wrote on :

Hello NG,

do you if there is any software or kext involved in the steering of the of the cpu-fan of a 400/500 G4 Titanium PowerBook. It seems that this Book has no readable sensors, so how is that done ?

Thank you for your time and help

Florian