I was just wondering if you guys think that my problem could have something to do with the tune. I am getting P0108 anytime you drive the truck on the highway for any period of time. The code is just a pending code and puts the tranny into limp mode until you cycle the ignition. the check engine light hardly ever comes on. The truck is a 07nnbs 5.3 with a magnacharger. thanks Mike By the way I have checked and recheck everything and seems to be fine I have even replaced sensor and smoke tested evap for any vacuum leaks. Voltage on sensor seems fine to.

 

Is this on the stock Magnacharger tune? What's probable happening is it's running a MAP rationality test when your in boost and throwing the code since the the 1bar MAP is maxed out. I don't know about the newer trucks, but in mine, I have it set to not run the map rationality test above 1500 rpm.

 

it was tuned by FMS in La but from what I have been told it has had this issue from day one with the factory magna tune and after his tune. But he says he never got this code pending whenit was at his shop

 

is the map test done asap after you start the truck or does it wait a few minutes? what determines when?

 

As far as I know it is a random test that can be done at any time.

 

Just looked in a stock tune for an 07 and its set at 5000, I would have them lower it to 1200-1500 and I think you would be ok. If they use EFILive, it's table C5501

 

thanks alot now if I can get them to call me back I can get it fixed!