When a start command of an engine is given in the presence of the driver's
power demand, the start control sets the ignition timing of the engine to
a power demand ignition timing, in order to enable quick output of a
large power from the engine in response to the driver's power demand.
When the start command of the engine is given in the absence of the
driver's power demand in a vehicle drive state, there is little
possibility of the occurrence of gear chattering noise because of
application of a torque to a driveshaft. The start control accordingly
sets the ignition timing of the engine to a vibration control ignition
timing, in order to reduce the vibration of the vehicle body. When the
start command of the engine is given in the absence of the driver's power
demand in a vehicle stop state, on the other hand, application of a small
torque may cause the occurrence of chattering noise. The start control
accordingly sets the ignition timing of the engine to a chattering
control ignition timing, in order to generate a certain level of torque
that prevents repeated contact and separation of gears in a gear
mechanism even in the event of an engine-induced torque variation.