have a 2007 duramax with an edge tuner that i installed in september 2012, and the truck just started showing 2 codes in the tuner p5062- system low voltage, which pointed at the ignition switch and u1041- loss of communication with ebcm. i changed ignition switch and the codes go away and come back in about a week. the codes show up when i go 2 shut the truck off, it stays running an extra 20 seconds then shuts off on its own. is the tuner causing this or something else? can any1 help me?