2011 Toyota RAV4 Owners Manual - Page 220

2 -4 . U sing ot he r driving syst e m s Four-w he e l drive lock sw it ch (4 WD m ode ls) Four-wheel drive lock mode can be used when a large amount of drive power needs to be applied to all the wheels, such as when the vehicle gets stuck in mud and you need to free it. Press the switch. The torque of the engine is distributed to the rear wheels to the maximum extent possible in accordance with driving conditions. Pressing the switch again cancels four-wheel drive lock mode and returns the Active Torque Control 4WD system to normal mode. (→P. 184)