An engine ECU executes a program including the steps of: detecting an
engine speed NE and an engine load (S100, S110); when determination is
made of being in an idle region based on the engine speed NE and engine
load (YES at S120), determining whether in a high load idle region or a
low load idle region (S130); reducing the operation sound by stopping a
high-pressure fuel pump in a high load idle region (S150); and aiming for
combustion stabilization without stopping the high-pressure fuel pump in
a low load idle region (S170).