Did you ever get this issue resolved? I just noticed this with my 100# mother over the past two weeks. More than half the time the "airbag off" light would come on with her in the seat. I took it to a local dealer service the other day and they ran some "NODRQX" test and it showed "no problem found at this time" so they replaced/reprogrammed nothing.
I just got off the Leaf chat with a Nissan rep. He stated that it could be my mother being on the lighter side, but he did indicate that the sensor is supposed to detect anyone over 80lbs, which is a good 20lbs below my mother's weight.
All he stated was that 1. I have my mother shift around in the seat to try to activate the sensor, which I did have her do unsuccessfully, 2. have a heavier person try sitting in the seat, and 3. bring the car to another dealer.
His suggestions only ticked me off more as 1. it is ridiculous to be asking a rider to be doing a little dance each time he sits in the car, 2. even if a heavy person appropriately triggers the airbag sensor, it does not help my mother's situation, and 3. another dealer will probably do the same NODRQX test and tell me nothing is wrong and repair/replace nothing.
I was able to get this problem on video. The service rep told me that even capturing the problem on video does not help any if they are still unable to reproduce the problem at the service center. I don't understand why if the car is under factory warranty, why they don't start replace one part after another until the problem is corrected like a reputable company is supposed to do. Like the OP, I may have to contact the NHTSA or seek legal advice by this point. Nissan should be obligated to put a sticker on the car stating that anyone under 100# should not sit in the front passenger seat. After this experience, this will definitely be my last Nissan ever.
I know about the 13-14 Leaf airbag recall. My is a '15.
