2 Questions - Auto transmission - Snow mode/Power mode and drivers airbag warning lite

[Andy_V35Sky_350GT]

Hey guys, two questions, on my 350GT, its got a button for snow mode and power mode. Now, I don't use snow mode as the car drives like its weighs 10000 tonnes in that mode, so i leave it in the middle position (which I am assuming is just an 'auto' mode). Now, if you flick it the other direction there is a 'Power mode'. Does anyone know how this is any different to the regular mode? I have a hardcopy of the 2005 G35 manual, but the snow mode botton is different in the G35. Any ideas?

Also, apparently there are sensors on the drivers side floor for the drivers airbag. The warning light keeps flashing in the dash, as been since I bought the car. Previous owner said it was a dead sensor and could be fixed for about $20. Is it just a fuse?