Originally Posted By: MrHorspwer
Originally Posted By: zoomie
I look at the condition once I find the locations of:
Throttle Position Sensor ( TPS )
Idle Air Control Valve ( IAC )
Idle Control Valve ( ICV )
Don't waste your time. Being throttle-by-wire (as you pointed out), your engine doesn't have an IAC or ICV and the TPS (actually, there are two of them) is integrated as part of the throttle actuator assembly.
You may want to just pop the intake tube off and give the throttle body a quick cleaning. A quick wipe of both sides of the blade and the throttle bore with a rag and some throttle plate and intake cleaner should do the trick. If you find it especially dirty, some additional elbow grease may be required. At only 25K miles, I don't think it will be too bad.
2009 w/ 29K miles should still be under warranty, correct? If so, I'd at least make a visit to the dealership to have them give it a once-over. They may not find anything (but hey, maybe they do), but at least you'll have a documented complaint if it becomes worse in the future. I know there aren't any Pontiac dealers left, but I would do my best to look for a store that at one time sold and serviced Pontiacs, like a Buick/Pontiac/GMC dealer that just became a Buick/GMC store.
In my case it wasnt a dirty ICV, but rather a dirty (higher-resistance) connection to the ICV.
IMO this could be the case and the OP never know it. Does the throttle open all the way, the right way, all the time? under acceleration, a little extra pedal, which may be unnoticable, might compensate. it is only thorugh issues like this that it can be determined that positions arent correct.
Just thinking out loud... Im sure those throttle positions are still adjusted by some type of a variable voltage signal... DBW or not.