Hi Hieu
KP0116 as far as the training notes go says that the AI PCB needs replacing, because "critical analog data is out of range".
Sounds as if you have a big problem, not a small one! You will need to contact the local representatives. Puritan Bennett is now part of Covidien in the UK, so you will have to do a bit of detective work on the internet to find your local rep.
All the best!