Airbag light flashing

The airbag light started flashing a few days ago unexpectedly. I was able to reset the light using the standard airbag reset procedure (turn key to on, wait till airbag light goes off, turn key to off for 5 seconds... repeat 3 times) but the airbag light starts to flash again within a day. I put it into the airbag diagnostic mode to see if there might be some trouble code, but I only get the 3 seconds on, 2 seconds off pattern. Factory service manual indicates a previous error code may not have been cleared. Unfortunately my ODB2 scanner does not read airbag trouble codes so the only option I have left is to take it to the dealer. Has anyone seen this or have any recommendations?

Truck is 2011 SV 4x4 with 190k miles.