I have a 2013 F150 STX Truck. When the weather is really cold (ranging -8F to -20F) at times when im letting my truck warm up to drive, the truck kicks into a "limp mode." The truck sounds like a diesel pickup and the blue wrench light becomes illuminated. I had taken it to my dealership but they do not find any codes. If I turn the truck off and turn it back on, it seems to run just fine. It happened a couple times last winter and stopped so i dismissed it, but now this winter in the cold it happened again. Any ideas or help? Thanks!