Have a 2006 Chev 4.8 Standard. Motor was blown, 6L swap. Everything was done right, immobilizer was on, brought to GM and removed immobilizer. Truck ran great for 7 years. Had a small miss at 2200 rpm, multiple misfire random cylinders, and had the 4.8 tune. Other Than that perfectly fine.
Fast forward to today. I bought the truck from a friend, knew this truck well, brought it to a friend of mine, he has tuned very little but has a bit of experience. Put a stock 6L tune on the truck, set it to standard, ran perfect but battery light and "Battery is not charging" was on. thought maybe the alternator was bad. Power enrich on truck is running awesome and works great.
Changed alternator and battery light is still on and so is the message. If i put my old tune back on it goes away. Im getting the code P0622 Generator Field Terminal Circuit (Current). If i put the regular 4.8 tune back on truck goes back to its old way and no light.
What is going on with the tune, i cant seem to find anywhere on hp tuner to mess with alternator stuff...
Please Help!!!