B0106/54 code after replacing air bar hardware

1995 Celica. Small front accident deployed both air bags, not air bars. I got both front sensors, both air bags, clock spring, air bag control module from salvage of a 1995 with rear accident. My mechanic has completed installation, but we can't get the air bag light to go out. Code is B0106/54, which according to the Modis unit, is "passenger squib circuit open". We've double checked all the connectors to insure that there are no bent pins or broken wires. Even shorted the pins together at each unit and ohmed them out back to the controller to insure continuity. (unplugged, of course)

Now the dilema. Is it that controller or is it the P air bag. I've heard many opinions. My gut feel is to go with what the controller is telling me and replace the P air bag. (This is the pricey one cause you have to pull the dash out.) Another option is to replace the controller first, since it's easy, and see if that resolves the problem. Basically, this is parts swapping. (fortunatley, the salvage yard is working with me on price and swapping hardware)

I've searched some on-line, but have not come up with any troubleshooting proceedures for air bag circuits. Seem most people are rightfully afraid of them for safety reasons.

Does anyone have advice or can point to some documentation on troubleshooting? I'd like to be very sure it's the P air bag before I incurr the cost of removing the dash for the second time.

Marc