airbag light

OK this is driving me nuts.... Wifes '08 Trailblazer got hit sitting in driveway a while back in the passenger side front door. All repairs done and everything was fine. Last week the airbag light came on, I got out the trusty scan tool, and checked the codes...the only code i got was B0078...

I have an 02 Trailblazer LS 4WD. When the temperature drops under 40 degrees the airbag light comes on and the seatbelt light flashes. The seatbelt light goes out on its own after a while and the airbag light will stay off after I turn the ignition off and restart after the cabin warms up. I...