I recently purchased a used 04 ZHP sedan with 115,000 miles on it. The owner told me that it had an intermittent airbag light that would come on after someone sat in the pass. seat and the light would clear randomly. I got him to take $200 off the asking price. The previous owners records showed that the passenger seat occupancy mat was replaced at 49,000 miles.
I didn't want to take the whole seat apart so I installed a Passenger seat occupancy mat bypass module.
Installation consisted of cutting the pass airbag mat wires loose and splicing the bypass module. After this was done the airbag light has not come back on. My airbag light was off when I installed the bypass. The airbagRX website states you may have to have a dealer clear the airbag light.
I purchased the bypass at http://www.airbagrx.com/
I hope this helps anyone with this problem.