Deterioration estimator for electronic throttle device

A method for estimating deterioration of an electronic throttle device, the method comprising:

• driving a throttle valve disposed in an intake passage of an internal combustion engine by a drive mechanism, wherein the throttle valve has a first opening position and a second opening position;
• and
• instructing the throttle valve to open from the second opening position, wherein the second opening position is on an open side relative to an opener opening position and in which the throttle valve is biased toward a closed side by an opener mechanism, to the first opening position, wherein the first opening position is on the closed side relative to the opener opening position and in which the throttle valve is biased toward the open side by the opener mechanism;
• detecting a behavior of the throttle valve when the throttle valve passes by the opener opening position;
• and
• estimating a deteriorated condition of the electronic throttle device based on the detected behavior;
• wherein the drive mechanism comprises:
• a motor as a drive source;
• a motor gear provided on an output shaft of the motor;
• a throttle gear configured to open and close the throttle valve;
• and
• an intermediate gear disposed between the throttle gear and the motor gear so as to mesh with the throttle gear and the motor gear;
• wherein the method further comprises estimating the deteriorated condition of the throttle device based on an idling time during which the intermediate gear rotates without rotating the throttle gear while a meshing state between the throttle gear and the intermediate gear is switching due to an effect caused by switching a biasing direction of the opener mechanism when the throttle valve passes by the opener opening position while being operated to close.

A method for estimating deterioration of an electronic throttle device, the method comprising:

• driving a throttle valve disposed in an intake passage of an internal combustion engine by a drive mechanism;
• and
• instructing the throttle valve to continuously operate to open from a first opening position, wherein the first opening position is on a closed side relative to an opener opening position and in which the throttle valve is biased toward an open side by an opener mechanism, to a second opening position, wherein the second opening position is on the open side relative to the opener opening position and in which the throttle valve is biased toward the closed side by the opener mechanism;
• detecting a behavior of the throttle valve when the throttle valve passes by the opener opening position;
• and
• estimating a deteriorated condition of the electronic throttle device based on the detected behavior;
• and
• activating the method while an ignition switch of the internal combustion engine is turned off and while the electronic throttle device is mounted on a vehicle.