Airbag / Passenger seat issue

2014 Tacoma TRD Sport.
Issue: Airbag light always on and passenger seat light blinking.
I had my mechanic run the codes and it came up with a whole list of airbag codes. B1650,B1653, B1655, B1660, B1821, and a few more. He said it sounds like a ground wire issue or something similar. Any idea’s on where to start on something like this would be appreciated. Truck has no other issues.

 

With those codes being for a bunch of different components of the system I would think it's a connector issue in the harness or a bad air bag ECU.
Have you had any probelms with water or moisture getting into the cab?

 

No problem with moisture since i have had the vehicle. Previous owner said the airbag light came on when the passenger seat was leaned back. Not sure if that’s really the case or not. I took the seat out and checked all connections but couldn’t see anything obvious. I’m taking it to the dealership tomorrow since this is foreign to me.