An ECU, which functions as a driving force distribution control apparatus for
a four-wheel drive vehicle, includes a CPU. The CPU controls a coupling for changing
torque distribution of front and rear wheels. The CPU determines either of first
and second torque distribution modes based on detection signals of a throttle opening
sensor and steering angle sensor, which are operating parameters. In the second
torque distribution mode, torque is distributed to the front and rear wheels more
equally than in the first torque distribution mode. The CPU sets a duration for
the second torque distribution mode when the second torque distribution mode is
selected. Until the duration elapses, regardless of the operating parameters, the
CPU continues the control of the coupling in the second torque distribution mode.
