Warning Light On problems of the 2012 Mazda CX9

I own a 2012 Mazda Cx9 . My wife weighs about 105lbs and about 115lbs with her usual lap dog. Initially the pax seat airbag warning light came on intermittently when she was in that seat, car in motion or not. The light was normal when I sat in that seat. Towne Mazda ran a test on the components. They informed me the system checked normal. However, the light after that then illuminated every time she occupied the pax seat. The problem was demonstrated to a service tech; the light was off with him in the seat (a larger man than me) and on every time my wife sat in the seat. She attempted to shift her position, but no position deleted the light. I was informed that the dealer would check with Mazda, to search for a solution. After month of using the car, the light has been on continually when my wife occupies the pax seat. The service supervisor told me to put her in the back seat because there is no way to fix the problem.