DTC 21-1x (21-10 to 21-19, 21-1A to 21-1F):Open or Increased Resistance in Driver's Seat Belt Tensioner
DTC 92-2x (92-20 to 92-29, 92-2A to 92-2F):Open or Short to Ground in the Passenger's Airbag Cutoff Indicator
Was the van in an accident?
The SRS mod isn't working if you have a 92-20 code. You'll have to change the driver's seat belt buckle/tensioner to get rid of the other code.
The tensioner has a small explosive charge in it like an airbag. When you're in an accident the charge goes off and takes the slack out of the seat belt causing it to be tight. You can't do anything with it except replacement.