To prevent the occurrence of an abnormal sound from an intake manifold in a strong negative pressure state when a throttle valve is opened from a fully closed state by the initializing operation of a throttle valve position sensor in the case where an ignition switch is turned off soon after the racing of an internal combustion engine.
In a termination processing routine initializing a throttle valve position sensor when an ignition switch is turned off, a throttle valve is set to a fully closed state and to a fully opened state so as to learn respective openings and thereafter, a termination processing returning to an off position is conducted (S14 to A22). Proceeding the termination processing, the throttle valve is held in a predetermined time at a predetermined opening (S12) so that a negative pressure in an intake manifold can be surely dissolved during this period.
HASHIMOTO TORU
MIYAKE MITSUHIRO
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