Passenger air bag is disabled
The Passenger airbag indicator says the airbag is off. Dealer service says this
requires a replacement of passenger seat cushion, a $1400.00 fix. is there
another way to enable the passenger air bag
It's a sensor system in the cushion. Dealer is probably changing the entire cushion with all its electronics because he doesn't want to change just a sensor. You could go to a salvage yard and see if you can find a matching seat and see if it has a good sensor. Or go to a different shop who will just deal with the sensor. Cost would be less, but not by a lot.
No warranty coverage?
My understanding is that the seat senses your electrical impulses, not just weight, so if you cover the seat or if your clothed legs aren't directly touching the seat (like on a cushion), it will show off.
Lots of small people use cushions. What about if you're wearing thick pants? When someone sits on the seat, the "pressure sensor" signals the occupant's weight to the ECU. The ECU then sends that data to the airbag, which has its own control unit. Based on that information, the vehicle's computer turns the passenger airbag on or off. That's why the airbag will deploy in a crash when a sufficiently heavy box is set on the seat.