Okay so I have read every post concerning this issue on here and other sites. Im at my wits end with this car i love it and gets great fuel milage.

So i bought the car back in august and I had to change the radiator because it got into a small fender bender and knocked the tab off of one side. Other than That car started and ran perfect. Next 4 day i put about 600 miles on the car.

This is when my problems started engine reduced power mode came on. Before it got worse i could pull over and shut it down and start it right back up no problems. Then i went to Wal-Mart one night and it refused to start again had to have it towed home. Scanner was reading crazy amounts of codes when all this was going on (but it was never the same code) so i started with crankshaft position sensor, fine for a while then did it by the end of that day. Its been giving me all kinds of throttle body codes so i cleaned it out and its good for a few hours then back into reduced power again. So i replaced the throttle body with ac delco. Same thing happens fine for a while then reduced power again. I replaced the battery, ecm, spark plugs, coil pack, ignition control module. Cleaned the mass air flow sensor, seafoams upper fuel injection cleaner.

Please somebody have a better answer for me. Everything I try seems to be fruitless a d im tired of throwing parts at it now.

These are the current codes its throwing.

 

I would look at the ignition switch circuit 2 code first. In older GM Pickups half of the ignition switch would fail intermittently and the automatic transmission would quit shifting. It may be a similar problem in your car, I do not have a fsm for an Ion.

 

Would that make it go into that reduced power mode? Its random as hell when it wants to do it. Like today it came on and refused to turn off no matter what ive tried

 

If the ignition switch circuit 2 is intermittent and it supplies power to the drive by wire side of things then yes. Like I said I do NOT have a factory service manual with wiring diagrams for your Ion. If you had an L series car I have factory service manuals.

 

Trying to recall if the ion has redundant throttle position sensors. One by the pedal, the other on the throttle body. When the two don't agree, the ECU figures it doesn't know where the throttle actually is, so it cuts power.

The fact that one of the codes says Accel position not learned seems to imply that the ECU does not have a learned mapping of throttle position vs pedal location (I think...). Anyway it doesn't know where the pedal is as it has nothing stored to compare it to.

However, it could also be a byproduct of what Andy mentioned. Plus did you get the position not learned code with the original throttle body?

 

I'm sure that it has those sensors because my scanner says they agree which is the weirdest part. That code appears in both ecms and both throttle bodies just depends how long after I clear the codes it takes to come back sometimes its instant. Sometimes it takes hours and it wont show up

 

I'll try changing that next hopefully thats my issue because ive pulled all the plugs on this car apart and dielectric greased them all