Error codes and rough idle

[pet575]

Got my transmission codes read the other night for a separate issue but also got two codes which were engine related. Not sure why I didn't have a SES light at that time but I've got one now. The codes were

P1000- OBD systems readiness test not complete
P0506- IAC valve duty cycle lower than expected

Someone has identified the P1000 as MAF related. Does that mean I should start by cleaning the MAF?

For the P0506 should I clean the IAC valve or should I be thinking about changing it? Confused because I was under the impression all this time that my setup didn't even have an IAC.

????

 

[pet575]

Possibly found an answer. I accidentally left the ignition on the other night and killed my battery. Some info out there indicates that these codes sometimes follow a dead battery or a disconnected battery condition. This thing has idled like crap for awhile though so I'm thinking of doing the cleaning of the throttle body anyway.

 

[05XLimited]

The P1000 is just a general code that is thrown stating that it cannot complete the test where it throws a code at startup. I would start by cleaning the MAF and the throttle body. The IAC functionality is built into the throttle body on the 2004-2005 V8s, and is controlled by the computer, with no physical IAC. If the code continues to be thrown, look for vacuum leaks.