I did some more research on this and found out some related information:
The QDM is built into the PCM The most common failures are the EGR solenoid or the Canister Purge solenoid.
Check all computer and sensor grounds.
Other information says it may be the ECM since a number of sensors usually don't fail at once.
The attached image may be helpful.
Saturday, October 1st, 2011 AT 8:24 PM