If they don't have their seatbelt and are sitting in the seat the SRS light will come on.
It is a warning that you or your passenger sitting in the front seat is not wearing a seat belt.
Simply fastening your seat belt should put the light out. If you have a heavy object sitting on the passenger side seat like a tool box or such that could trick the light to come on. If not you have something disconnected or broken.
In NZ, where I live, sitting in the front passenger seat is standard practice.
Cc while sitting in the front seat
it doesn't turn on if there's no one sitting in the passenger seat
I understand that the fuel filter is located under the bottom of the car directly under the passenger seat. You must remove the under covering to get to the fuel filter
Your mother-in-law is sitting in the passengers seat.
it has to do with the air bag when it is deployed, a small child sitting in the passenger seat can sustain terrible injuries
Could be one or more of the load cells under the passenger seat have gone bad. Just a guess. Take a look and see if you can see wire damage under the passenger seat.
My "Passenger Airbag Off" light is illuminated even when I have a passenger is in the right seat. Isn't there a sensor in the right seat that is supposed to turn the airbag on when I have a passenger?
In most newer cars, no. Older cars may not even have an airbag for the passenger. In most cars that do however, there is a weight sensor in the passenger seat that turns the airbag on only if there is someone heavy enough in the seat. This prevents the airbag from deploying if no one is in the seat and also prevents it from going off if there is a small child in the passenger seat.
You have to remove the 28 mm bolts at the rear of the passenger seat on either side of the tail light. Now slide the passenger seat back to release a clip holding the front edge of the passenger seat. Then remove the 12 mm bolts holding the seat to the frame.