From what I have seen:Did you find the answer..if yes than please post here.. Even I am curious about the same
In Application Status under Background check,
"Your application is in progress. We will send you a message when we start your background check." - This message indicates IP1
and
"We are processing your background check. we will send you a message if we need more information" - This indicates IP2
During IP2 they will contact you if they need anything.
This message in Background check will not change until after you receive your permanent residence . It wont change even after getting "Ready for Visa" email which asks you to send your passport and photos to their address.
So keep checking your emails when you are in IP2, you may get an approval email in your inbox and there will be no update on the cic page.