Airbag sensor

I have a 2014 tacoma and I often have my stepson riding with me and I have noticed that it does not come on when he is sitting in the passenger seat he weighs 96lbs whats wrong is the sensor bad. The truck had just gotten its first oil change so mileage is very low

 

Not 100% positive but I think I read that the passenger has to be over 100lbs to activate it. Can you have him sit in the seat with a gallon of water and see if sensor shows correct? That should be enough to get him over the 100lb threshold. I've had my 70lb dog riding shotgun and it keeps the air bag off but does warn that the seat belt isn't plugged in, so I know it's detecting someone in the seat, just not heavy enough for the air bag.

 

Not a bad sensor, it's his weight.