Starts... but no idle (sometimes)

If anyone can help, it would be greatly appreciated! One morning, out of the blue, my truck refused to hold an idle. It would start up fine, but then die right away. If I start my truck and hold down the gas, it will stay running but once I left off the gas, it dies. My check engine light came on and I took it to Autozone. The codes translated to "Low Circuit Mapping". Anyone knows what the hell that means? = ) Anyways, I was thinking it might be my TPS(throttle position sensor) or IAC. Any thoughts or links to sites with instructions on how to fix the problem? I really appreciate it!

Sorry... this is for a '96 1500 Ram 5.2L V8 Thanks!!!

I found a hose that was not connected to the air filter box that is connected to the PCP valve. I've reconnected the hose but doesn anyone think this may have been the problem??? Thanks!

Probably the MAP sensor, but I don't know anything about those things and how and where to change them. The other guys here will know for sure.

http://www.allpar.com is a real good site.

Sounds like some other posts about 'won't idle'. May be the TPS, cheap replacement.

I had the same problem except no check engine light, and it was recommended by someone on here to try cleaning the IAC and I did that and seems to run better now, and I also cleaned connections to the TPS, and the IAC.