Originally Posted by JHM2K

I'm going to go out on a limb here and say that the replacement unit built for market claims has a line (or five) of code that doesn't jive with the OEM airbag control unit, and it's popping the code. With the ever-increasing complexity of systems in cars these days, it's a very common problem if the past-point-of-fit (PPOF) component is going into a 10+ year-old car.

A major supplier for lane-departure warning systems for Nissan struggles with this issue a LOT. I'm one of the guys that approves the Parts Submission Warrants for these SW changes, and ten times out of nine there are issues detected downstream when the factories overseas have to do PPOF replacements.

TL,DR version -- he needs to borrow Star-DAS to fix it. But it's fixable.