This 2002 Chevrolet Trailblazer came in with the airbag light on and codes B0028, B0029 & B0030 for passenger side air bag wiring faults. Something that has had a hard time sinking into my head is, when the scan tool states that there is a problem with a passenger or driver side air bag, SIDE is the important term. It means the SIDE airbag on the passenger or driver side of the vehicle. It does NOT refer to the dash mounted airbag on the driver or passenger side of the vehicle.
I have found a lot of these problems are caused by detailers at used car lots, removing the seats for cleaning the carpet and then forgetting to reconnect the harnesses. A quick look under the seat and I saw the chewed up wiring shown below.
A couple of quick splices.
I then placed the harness back into the split loom and fastened into position. I ran the power seat back and forth, and up and down to make sure the wire was away from moving parts. I informed the customer that this was considered a temporary repair under manufacturers guidelines. To my knowledge no manufacturers recommend repairing airbag wiring. Instead they recommend harness replacement.