The "U" codes are communications codes. Not uncommon. They are most likely related to what I'm about to tell you about the other codes since they involve the modules I am goign to tell you about. The "C" codes are an ABS issue. I can tell you with 99.9 percent certainty what the ABS issue is, and you will not like it. The EBCM (C0265, C0291 (and U Codes most likely)) and the BPMV (C0267) will need to be replaced and the ground wire for the EBCM will need to be re-located to a better area. I see an average of 2 of these a month on the trucks at the dealer I work at. The parts are roughly $1300, and i don't know what labor is in your area, but you can expect about 4 hours time. As far as the brights coming on during T-Sig operation, that is a different issue. Sounds like the multi-function switch in the column has gone bad, or you have a serious electrical feedback issue. Check your lighting grounds for good contact and CLEAN connections. If they are ok, replace the switch.