Airbag light does not remain off, blinks out then back on?

Okay, the open circuit is saying the wiring or connector has an open connection. I would remove the connector at the pretensioner to see if there is a pin that got pulled out a little. Also, here is a guide to help you test the connections and the airbag wiring diagrams so you can see what to test and how the system works:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

So, if you have a new seat belt pretensioner, and the wiring and connections are good this means the airbag module is not good. I did notice the airbag module is under the passenger's seat which can be exposed to moisture so I would make sure the grounds are good and that there is no corrosion on the connector to the module. Here are the instructions in the diagrams below on how to change the module out.

Sorry about that, it is under the center console. Here is a better image of it.