Ok fellers I checked the codes in the odo window the other day and I got a PO122 APPS volts low code. So I then proceeded to check it, and found that it was reading ~.462v when the sticker says it should be .483v. I adjusted it and then took the ground cables off the batteries to reset the fault codes and also allow me to reset the APPS. After doing this, installing a new IAT sensor and removing the grid heaters, I notice the power is much stronger on the bottom end with the comp on kill, but kinda weak up top where it was once strong. I now only make 28psi of boost where I was making 36psi. I expected some loss due to removing the grids but not 8psi. I checked the codes again this morning and found that PO122 is back again. Anybody got any suggestions?

 

still having this problem?

 

Ran the dog crap outta the truck yesterday and saw 34psi. Much better than 28. PO122 is still there though...

 

I was getting 28 psi,then 32,then 28...had a darn boot leaking

 

hmm... well i wouldn't know where to start with getting to the bottom of that code, but here a bump for ya

 

Are you sure the code ever really went away when you unplugged the batteries and did you un-hook both batteries. Just askin the obvious first since those are the most likely things I always don't think about when I'm doin this stuff.

The other thing I would look at would be pulling all 3 sensors, checking continuity on them and cleaning them if they still check out as good.

 

I dont really have a clue as to whats goin on with it now. Everything is set right, and it will make 34 psi, which is acceptable since I removed the grids, and it runs like it used to again. Code is still there, and it was gone when I reset the APPS. I may stop by Autohell and use a scanner to clear it and see if it comes back again.

 

Personally I've never been able to clear any codes by unhooking the batteries. But I know others say they have so I don't know if it's just my mixed up truck.