Whats the red button in front of the gear handle on a Toyota rav 4 automatic for?

Mk 1 or Mk 2?
If it's the Mk 1, I think it's the differential lock for the centre diff.

mabey its for traction assist or overdrive? I have a 4runner, but its not that new...my moms corolla has a button on the side of her shifter and its for overdrive.

I think for 4 wheel drive even though i dont have 4 wheel drive

I wish I knew! I do drive a Rav 4 and have just trawled through the owner's manual and although there is a picture with the button showing it doesn't say what it's for. I don't think it's anything to do with the 4wheel drive as the Rav is always in 4wheel drive mode. Hopefully someone else will know - if not I'll try calling my Toyata garage.