It "could" be a faulty weight sensor. which is likely part of the seat cushion. One would need a capable sensor to check for stored codes. Being a 2014 model, I would think it would be covered under warranty, so I would make an appt. with your local Nissan dealer.
This Video was after it has been from the Dealership for a new seat sensor & wiring Harness. I had broght it back to get checked 4 times now just for this issue. There suggestion is to have someone older & heavier than my 18 yr old son to sit in it instead, which is very ridiculous.. Nissan wont even tell the dealeship technicians on what weight those seat sensors are rated for..