My 2005 GTR started this years ago. It was a problem for ALL Nissans of this vintage in general. There was online information using key on, key off sequences and pushing the door button so many times in between that would reset it. I did that and finally found one that worked.....................for a while. Then, when I could no longer to get it to stay off using that, I took it to the dealer. They said it was the passenger seat air bag sensor and had to keep the car for a couple of days while they ordered it. When I got the car back, light was off and stayed off.
But, one day, two months or so later, when my wife went with me somewhere, I noticed she had failed to put her seat belt on and there was no warning light. I had not had anyone in that seat since the dealer "repair" so, hadn't been aware. So much for that dealer and their "repairs". Lord knows what they did to get the light off and then sent it out defective like that. No need to go back and argue because, why would I trust them now.
Then, a month or two later, the air bag warning light began to come on again. I just kept resetting it and it would stay off for a while. Finally, it just kept coming back on within a few minutes of driving after a reset. So, I've lived with it since. Figuring I'd buy a code reader and fix it myself someday. It was a main reason I joined this forum.
Of course, I never have.
If you find some miracle cure, do please share. Even the dealerships can't seem to get this one right.