I'm a 1st time diesel owner, bought a 2004. 5 3500 srw in November and am loving the truck. However about a week ago I left the house on a 130 mile trip and the TC wouldnt lock up... tried stopping, shutting off and restarting truck, speeding up, slowing down, etc. finally just set the cruise at 2000 rpm's. After about 15 miles of this all at once it shifted into OD and performed flawlessly the rest of the trip. Next couple days went fine then today same thing, drove 12-15 miles before it shifted into OD. Flashed 2 codes... P 0243 and P 2127. The 2127 has to do with the pps, could that cause this problem?