2012 Toyota Highlander traction control light

nope. scan for codes and check and clean the connections at the wheel speed sensors. also check the wiring in that area for rubbed spots. Vehicle that new though should have a code that will help you out.

Yes. When you do that, the brake stays activated for a few seconds after you release the brake. It's the Hill Start Assist, so the vehicle doesn't roll back when you move your foot to the accelerator.