When a starter switch is switched from OFF to ON, a hybrid ECU determines
that a driver intends to start driving a vehicle, reads a temperature of
each of items (engine coolant, injectors, lubricating oil, and the like),
and makes a determination on the necessity of preheating depending on
whether each of the items has reached a corresponding one of suitable
temperatures. If preheating is required, the hybrid ECU sets an engine
start permission flag so as to prohibit the engine from being started,
and instructs an engine ECU to preheat the item requiring preheating. On
the other hand, if every one of the items has reached the suitable
temperature range of its own, the hybrid ECU determines that preheating
is not required, and sets the engine start permission flag so as to
permit the starting of the engine.