how to troubleshoot the eva system for leaks on a volvo 2006 xc70 .

TRY A NEW GAS CAP.

First step Volvo would do is upgrade the the engine control module software. For the most part that will usually fix your problem. If you are in the USA call Volvo to see if they are participating in the Volvo service for life program. If they are they will diagnose your check engine for free. The software is covered by a 10 year/ 150k mile emmissions warranty if one is available. I would start with that. Let us know what happens.

already did the update of software, problem continu.
how can i check this at home ?

You need a smoke machine to see if evap lines are not leaking. If ok check purge valve is properly closed and sealed and check canister shut off valve for proper operation. If all is good then the leak detection pump is bad. Very prone to failing.