I have a 2010 RAV 4…
Years ago, I specifically read the part in my owner’s manual that pertains to
4WD.
To manually engage the 4WD, there is a button just to the right of the steering wheel. When the vehicle approaches around 22mph, the 4WD shuts off.
If your RAV4 senses wheels starting to lose traction, the 4WD will engage automatically and disengage when not needed.
.