Demonstration of 4Runner in 4 Wheel Drive.
4WD in high
4WD in high with center differential (diff) locked
4WD in low
4WD in low with center differential locked

With the center differential lock switch engaged the front and rear axles are locked together for better traction.
The VSC is disabled ( VSC off light comes on) when the center differential is locked.

The 4Runner also has ATRAC. This system simulates a limited slip differential in the front and rear.