Here is what i found by searching the internet.
First let me say that you will probally need a factory service manual to properly test, service and repair this system,,aftermarket sevice manuals like the one you bought for twenty dollars do not provide enough information.
1. There may be a technical service bulletin concerning this system on your vehicle, consult with your local GM dealer for details.
2. Go to this web site http://www.obd-codes.com/p0410
Read the whole page, click on,,,this ACDelco site, you will see information on vehicles with this problem,,they may not be your exact year model, but information is information.
3. Go to this web site http://forums.trailvoy.com/showthread.p
This forum discusses the problem you are having,,look at the posting by, the roadie,, posted on 06/16/2009
You will see the secondary air pump and an image of the secondary air injection system.