A mode establishing section of a differential limiting control apparatus for a
four wheel drive vehicle commands an automatic mode control section or a manual
mode control section to output calculated clutch torques according to a signal
from a mode switch operated by a driver. In an initial condition of an ignition
switch turned on, the execution command is issued to the automatic mode control
section, until the driver newly selects the manual mode through the mode switch.
Further, when the vehicle travels at a speed higher than a preestablished threshold
value, the execution command is outputted to the automatic mode control section,
irrespective of the signal from the mode switch.