Does anyone know what code 1511 "EFI Power Management Mode" really means?

Every now and then my 09 wont start and I have to clear the codes to get it to start. It restarts after clearing and then it throws a P1511 which comes straight back after clearing. Sometimes she idles at 1500 or more for a while until you blip the throttle. I always wait for her to idle for a couple of seconds before shutting down.

Does anyone know what this code really means? Power management mode doesnt seem to mean much, I ran her up to 120 yesterday and I would say the EFI is doing a good job of power management!

I have read a thread a while back about the 58mm TB being unreliable, I wonder if this has something to do with it?

 

Attached explains it.

 

Thanks Dawg. it is a throttle body problem as i feared. The code hangs around for another cycle which explains everything.