Abstract: A method and device for monitoring the functionality of a valve stroke adjusting device of an internal combustion engine in a cold start phase. The internal combustion engine includes an electronically controllable throttle, the control utilizing an integral component to control the throttle, and the functionality is monitored by determining the integral component in a cold start phase, comparing the integral component with at least one predetermined threshold value and evaluating the functionality of the valve stroke adjusting device on the basis of the comparison.

Abstract: An actuator for a control unit has a control motor with a motor power takeoff shaft; a control shaft that carries the control unit; and a step-up gear, disposed between the motor power takeoff shaft and the control shaft, as well as a restoring device for restoring the control unit to a basic position if the control motor fails. To make it possible to use a single-stage step-up gear with a major step-up ratio and with advantages in terms of installation space, weight, and production costs, the restoring device has two separate energy-storing means, preferably embodied as restoring springs, of which one feeds back to the motor power takeoff shaft and the other feeds back to the control shaft.

Abstract: A device for actuating at least one throttle valve of an internal combustion engine is provided. When the throttle valve opening angles are small, the throttle valve and the actuating device are positively coupled, and when the throttle valve opening angles are large, the throttle valve and the actuating device are form lockingly coupled in the closing direction, but are only conditionally coupled in the opening direction, such that the throttle valve can be brought into operation for smaller throttle valve opening angles.

Abstract: An electric throttle control apparatus for an internal combustion engine includes a throttle motor that operates the throttle valve. A throttle control unit controls driving duty for operating the throttle motor. The throttle control unit determines a tapping operation for learning a full close position of the throttle valve to be completed when the accelerator position is at a substantially minimum position, the opening degree of the throttle valve is substantially constant in the vicinity of the full close position, and the driving duty for operating the throttle motor with respect to a close direction of the throttle valve becomes equal to or greater than a threshold. The throttle control unit restricts the driving duty to be equal to or less than a driving duty limiting value, thereby maintaining the throttle valve in the full close position, when the throttle control unit determines the completing condition to be satisfied.

Abstract: A fail-safe mechanism of an air induction control apparatus for automotive engines is provided which is designed to hold a throttle valve at a middle position when a valve actuator has failed to move the throttle valve. The fail-safe mechanism includes a middle position hold stopper, an opener lever connected to the throttle shaft, and a first and a second coil spring. The first coil spring works to exert a first spring pressure on the opener member in a first rotational direction in which the throttle valve is rotated from a fully opened position to the middle position. The first coil spring is urged at an end thereof into constant engagement with the middle position hold stopper to hold the opener member from rotating in a second rotational direction opposite the first rotational direction. The second coil spring has a first and a second end between which the opener member extends. The first end abuts against the middle position hold stopper.

Abstract: An operating apparatus of an engine in a portable working machine improves an operability of a throttle lever while preventing a Run-on phenomenon or the like. The operating apparatus is provided with a first operating device for operating a throttle valve of the engine in a range from a fully closed state to a fully opened state, a switch for switching the engine between an operable state and a stoppable state, and a second operating device for operating the switch. The second operating device is structured so as to regulate an operation position of the first operating device at a time of operating the switch such that the engine is brought into the operable state, and to allow the first operating device to fully close the throttle valve at a time of operating the switch such that the engine is brought into the stoppable state.

Abstract: When ENG frames created in an ENG transceiver unit and ECT frames subjected to gateway processing in an ECT gateway processor are transmitted around the same time, a transmission mediating unit alternately transmits each of the ENG frames and the ECT frames. Therefore, as compared with a case where one type of frames are preferentially transmitted, transmission of both types of frames can be started at the earliest timing.

Abstract: Limitation of the opening rate of the throttle valve is prohibited unless the following conditions have been all satisfied: (i) the engine speed detected at starting opening the throttle valve is below a prescribed speed; (ii) the throttle angle detected at starting opening the throttle valve is below a prescribed throttle angle; (iii) the target throttle-open angle is above a prescribed throttle-open angle; and (ix) the target opening rate of the throttle valve is above a prescribed opening rate.

Abstract: A method and a device for operating an internal combustion engine are provided, which allow a continuous limiting of the output of the internal combustion engine upon attaining a maximally possible injection duration of an injection valve. The internal combustion engine has at least one actuator for influencing the output of the internal combustion engine and at least one injection valve for supplying fuel to the combustion engine. A maximally possible injection duration for an injection procedure of the at least one injection valve is determined. A variable characterizing the output of internal combustion engine is limited as a function of the maximally possible injection duration by corresponding adjustment of the at least one actuator.

Abstract: An engine control strategy that ensures that NOx emissions from the engine will be maintained at an acceptable level. The control strategy is based on a two-dimensional fuel-air curve, in which air manifold pressure (AMP) is a function of fuel header pressure and engine speed. The control strategy provides for closed loop NOx adjustment to a base AMP value derived from the fuel-air curve.

Abstract: A secondary engine speed control mechanism for small internal combustion engines, including an operator control which is manually operable to override an engine running speed which is set by the engine's primary speed control mechanism and governed by the governor. The secondary speed control mechanism may be selectively actuated by the operator in anticipation of an increased engine load to provide a temporary increase or “boost” to engine speed above the set, governed engine running speed. The secondary speed control mechanism may be either mechanically or electrically actuated, and may include an operator actuated, trigger-type mechanism or an electrical switch located on the handle of an implement with which the engine is used.

Abstract: According to the present apparatus, there are provided throttle valves 20 that are disposed in intake passages, a throttle shaft 30 that supports the throttle valves 20 to be opened/closed, drive means 40 that rotatably drives the throttle shaft 30, and a torsion type return spring 50 that deforms in a manner interlocked with the turn of the throttle shaft 30, and returns the throttle valves 20 to a rest position on a close side, and a deformation force transmission mechanism 60 including a speed reducing gear 62 is provided to cause a torsion deformation on the return spring 50 within an angular range smaller than the rotation angle range of the throttle shaft 30. As a result, the maximum energizing force is reduced. Consequently, the maximum energizing force of the return spring is reduced on the throttle apparatus where the throttle valves are returned to the rest position by the return spring.

Abstract: An electronic throttle body control system (100) and method provides accurate control over a throttle plate (102) position via various functions. An ice breaking function detects whether there is ice blocking the path of the throttle plate (102) and vibrates the throttle plate (102) to break and remove the ice. A mechanical stop confirmation function that confirms a mechanical stop position each time the vehicle is turned on to ensure that adaptation values for the throttle plate (102) are calculated accurately. A miswiring detection function detects miswirings by detecting whether the actual movement of the throttle plate (102) is in a direction opposite to the setpoint target direction.

Abstract: The maximum driving power of a throttle motor is temporarily increased when a throttle valve is determined or expected to be in a seized-up or semi-seized-up state, which increases the possibility of the throttle valve being released from the seized-up or semi-seized-up state.

Abstract: A propulsion system for a watercraft includes an engine. An air intake device delivers air to a combustion chamber. A throttle valve regulates an amount of the air. A control device sets the throttle valve to a desired position. A remote controller provides the control device with the desired position. The engine can include an auxiliary intake device that delivers supplemental air to the combustion chamber. A control valve normally shuts the supplemental air from the combustion chamber. The control device determines whether an abnormal condition occurs in setting the throttle valve to the desired position. The control device determines whether the amount of the air is insufficient. The control device controls the control valve to allow the supplemental air to move to the combustion chamber when the control device determines that the abnormal condition occurs and the amount of the air is insufficient.

Abstract: Apparatus are provided for an electronic throttle control (ETC) system having a throttle body assembly. The apparatus includes a throttle actuator, an input circuit receiving sensor signals and having first, second, and third reference voltages, a first throttle position sensor (TPS) connected to the second reference voltage, a second TPS connected to the second reference voltage, a manifold absolute pressure (MAP) sensor connected to the first reference voltage, a manifold airflow (MAF) sensor connected to the third reference voltage, and a processor connected to the input circuit and transmitting a control signal to the throttle actuator based on the sensors, reference voltages, and returns. The ETC system has improved remedial actions responsive to failures of the various sensors, reference voltages, and returns.

Abstract: A motor vehicle (20) has a diesel engine (22) and one or more sources (30, 36) providing data relevant to operations of the vehicle that are external to the engine but potentially influential on fueling of the engine. An engine control system (24) processes data according to an all-speed governing strategy for controlling engine fueling to develop all-speed governed fueling data (MFGOV) that sets engine fueling when a data input to the engine control system from the one or more sources discloses no need to influence engine fueling. When the data input from such one or more sources discloses a need to influence engine fueling, that data input causes engine fueling to be set by a strategy other than the all-speed governing strategy, a torque speed control strategy (54) in particular.

Abstract: In a method for operating an internal combustion engine, the fuel is supplied via at least one injection valve. The injection fuel quantity is influenced by the injection duration. In order that the internal combustion engine be operated optimally with respect to emission and comfort, it is suggested that it is predicted whether a requested injection duration of the injection valve become greater that a maximum possible injection duration. If the prediction yields that a case is imminent, at least a quantity, which is decisive for the combustion, is on influence that the torque (M) is gently reduce.

Abstract: The present apparatus includes an accelerator pedal 10, a pedal arm 20, a pedal shaft 30 which supports the pedal arm 20 so as to be free to swing, a return spring 40, a friction generating mechanism 50 which generates friction force corresponding to a position of the pedal arm 20, an accelerator position sensor 60 and a control segment 70 which controls an opening of a throttle valve 110 based on an output signal of the sensor 60. A play range in which a friction force equal to or larger than a specific level is not generated is set to the friction generating mechanism in the range where the pedal arm moves from a resting position by a specific amount. In the play range, an output signal of the accelerator position sensor 60 is kept constant so that the throttle valve is kept at a specific opening. In this manner, a desirable operating feeling without an unsuitable feeling with the accelerator pedal operation is obtained, and the accelerator apparatus is compact.

Abstract: A method and a device are described for filtering a variable. A first filtering arrangement is used for forming an output variable as a function of an input variable, the first filtering arrangement having at least a delaying effect. The input variable of the first filtering arrangement is corrected using a correcting variable which is obtained by starting from the input variable of the first filtering arrangement and by filtering, using a second filtering arrangement.

Abstract: That is an electronically controlled throttle device comprising a throttle valve held rotatably in a throttle body; an actuator for driving the throttle valve; a return spring which gives a force to return the throttle valve in the full open direction; a throttle position sensor for detecting the opening of the throttle valve; and a throttle actuator control unit for driving the actuator based on the opening of the throttle valve detected by the throttle position sensor and a target opening. Wherein the throttle actuator control unit is provided with a control means which controls the actuator, when EGR control or DPF control has ended, so that the throttle valve turns toward the full open position in a longer period of time than the length of time in which the throttle valve is turned toward the full open position by the return spring only.

Abstract: A method and system of throttle calibration control is presented that includes a TPS designed to provide an output indicative of throttle plate position when the throttle plate is opened and provide an output of throttle actuator position when the throttle plate is closed. The TPS output is received by an ECU to control subsequent engine operation. When an input is received from the TPS indicating that the throttle actuator is within a pre-set idle throttle position range and below an idle position benchmark, the ECU automatically reestablishes present and subsequent engine operation.

Abstract: A vehicle electronic controller for checking a control microcomputer with a common monitoring IC, which is used in different vehicles. The vehicle electronic controller includes a control microcomputer, which calculates control data to control an actuator installed in a vehicle in accordance with a driving condition of the vehicle, and a monitoring IC, which is connected to the control microcomputer and checks whether or not the control data is normal based on a determination value. The control microcomputer provides the determination value to the monitoring IC. The monitoring IC includes a memory device, which stores the determination value in a rewritable manner. The monitoring IC receives the determination value and stores the determination value in the memory device.

Abstract: A series type hybrid electric vehicle that controls an internal combustion engine, generator, and electric motor for reducing the load applied to the internal combustion engine when the internal combustion engine is restarted, lowers the thermal stresses to the internal combustion engine when the engine is turned off and is able to remove excess fuel when turning off the internal combustion engine.

Abstract: In a throttle device for a multipurpose internal combustion engine having a throttle valve connected to an electric motor and a carburetor, when an instruction to stop the engine is inputted, the electric motor is controlled to move the throttle valve in a fully closed position so as to stop the engine, and then to move the throttle valve in a fully opened direction. With this, throttle valve can be surely opened to facilitate restarting, and the occurrence of dieseling and run-on is prevented without providing a fuel cut valve to the carburetor. Further, a spring is provided to urge the throttle valve in an opening direction. With this, the response in opening the throttle valve is enhanced and the size of the motor is reduced.

Abstract: A control for controlling an intake air into an engine is provided. A control valve for adjusting an amount of the intake air into the engine is provided. A desired opening degree of a control valve provided in an intake air passage into the engine is determined based on a clogging coefficient. The clogging coefficient indicates a degree of clogging of the intake air passage. An opening degree of the control valve is controlled to converge to the desired opening degree. The clogging coefficient is updated based on a feedback correction amount for feedback controlling a rotational speed of the engine during idling operation. If a leakage in a blow-by gas passage that is connected between the engine and the intake air passage is detected, the update of the clogging coefficient is prohibited.

Abstract: A final control element movable between a minimal and a maximal position for controlling an internal combustion engine is acted upon by a first spring element acting in the closing direction and a second spring element acting in the opening direction, the latter having a first end and a second end. The first end of the second spring element is supported in stationary fashion in a housing. The second spring element transmits its intrinsic tension in the tangential and radial directions either to a bearing point on the final control element or to a second bearing point of the housing and is adjustable in its angular position by means of an adjustable stop.

Abstract: A method for operating an internal combustion engine and a device for executing the method which are based on the fact that a throttle valve is situated in the intake port and an exhaust emission control device is situated in the exhaust system. The air flow setpoint value for the throttle valve is changed following occurrence of a request for heating and/or regenerating the exhaust emission control device. A first diagnostics of the throttle valve provides an error signal in the event of a throttle valve error. When the error signal and the request are present, a switch is made in a characteristics map from a first or a second dataset to an additional dataset on the basis of which at least one control signal of the internal combustion engine is provided.

Abstract: In one embodiment of the present invention, a system is disclosed for monitoring the backpressure produced by a particulate filter of an internal combustion engine. When the backpressure of the engine exceeds a predetermined threshold, indicating that the particulate filter should be serviced soon, an input to the electronic control module (ECM) indicating the intake manifold boost pressure is shunted to ground, thereby giving the ECM a false indication that no boost is being applied to the intake manifold. This will cause the ECM, according to its normal engine management software, to derate the engine performance to a “no air torque setting”, thereby limiting the amount of torque that the vehicle operator can extract from the engine. This decreased performance of the engine provides a very high incentive to the vehicle operator to bring the vehicle in for servicing, at which point the particulate filter can be serviced.

Abstract: A throttle plate manipulator, for allowing an engine to operate that has a throttle plate, the throttle plate having a gas mixer having cross-hairs including a main opening and vertical and horizontal bars extending across the opening, the throttle plate having a butterfly located behind the cross hairs that controls the engine speed. The manipulator includes a manipulator disc that secures over the cross-hairs using an attachment rod having a hook that hooks behind one of the bars of the cross-hairs, and a control rod that extends through the manipulator disc and engages the butterfly. Fuel-air flow into the engine is allowed and adjusted as desired by rotating the control rod to advance the control rod toward the butterfly.

Abstract: A servo-assisted butterfly valve for an internal combustion engine comprising a valve seat, a butterfly body engaging the valve seat, a shaft on which the butterfly body is keyed, an electric actuator coupled to the shaft, an elastic member which is adapted to exert a torque on the shaft which tends to rotate the butterfly body towards a limp-home position and an abutment body which comprises an eccentric member which forms an abutment surface for an abutment member of the elastic body in order to stop, in the desired limp-home position, the rotation of the butterfly body caused by the elastic body in the absence of action by the electric actuator.

Abstract: A drive device enabling a movable element to be driven by an actuator via a gear system comprising a motor pinion gear, an intermediate gear and a partial toothed gear. An aim of the invention is to create a particularly compact device which can capture the kinetic energy of the actuator in a particularly reliable manner. The intermediate gear comprises a pinion and a toothed gear. The pinion and toothed gear are connected via a ratchet in such a way that the opinion which is rotationally fixed to the ratchet can be rotated counter to the toothed wheel in a manner similar to that of a locking ratchet wheel.

Abstract: An engine torque control apparatus for controlling the output torque of an engine (60) connected to a transmission (40) in a vehicle has a temperature sensor (55) for detecting the temperature of oil used by the transmission (40), and a controller (50) for limiting the output torque of the engine to an engine torque limit or less. The controller (50) functions to compare the oil temperature with a specific temperature, to set the engine torque limit to a first limiting value when the oil temperature is equal to or less than the specific temperature, and to increase the engine torque limit at a predetermined increase rate when the oil temperature exceeds the specific temperature.

Abstract: An intake air amount control apparatus for an engine is capable of stabilizing the controllability of a valve (10) as well as reducing the number of component parts required. A coil spring (11) includes a first spring portion (11a) having a first end portion (12), a second spring portion (11b) having a second end portion (13), a joint portion (19) that connects the first spring portion (11a) and the second spring portion (11b) with each other. The first end portion (12) of the first spring portion (11a) and the second end portion (13) of the second spring portion (11b) are attached to a body (9) through a movable member (14), and the joint portion (19) is attached to a final spur gear (4).

Abstract: The present invention relates generally to combustion engines, and more specifically, to an apparatus for controlling the power of combustion engines which have electrically-modulated throttle systems (also known as drive-by-wire throttle systems). There many applications in which it is desirable to modify the throttle control system of vehicles, for example, in limiting the power production of trucks operating in under ground mines. It is prohibitively expensive for vehicle manufactures to supply such modified vehicles, so a system must be provided and installed as an after market product. The invention provides a simple and inexpensive solution in the form of a voltage modifying device which can be installed inline, between the accelerator pedal sensor and the engine control unit. The voltage modifying device can be designed to limit the power of the engine, or alter the performance profile in a desired manner.

Abstract: A method and an arrangement control the output quantity (NMOTACT) of a drive unit (1) of a vehicle. The method and arrangement make possible a time-optimal control strategy especially during a shift operation of the vehicle. The output quantity (NMOTACT) is adjusted with the aid of an adjusting quantity (MDES) and tracks an input value (NMOTDES). In at least one pregiven operating state of the vehicle, the actuating quantity (NMOTDES) is brought to a pregiven limit value (MO, MU) when a pregiven control deviation (dnv) of the output quantity (NMOTACT) is exceeded.

Abstract: A method and an arrangement for monitoring a pressure sensor are suggested which determines a value representing the ambient pressure of an internal combustion engine. Furthermore, an index for the extent of the correction of the mixture composition via the mixture control system is determined and the supplied air mass is detected from the throttle flap angle and the intake manifold pressure. A fault in the determination of the ambient pressure is detected when the measured air mass deviates from the computed air mass and the correction of the mixture control system is less than a predetermined limit value and when, for an open throttle flap, intake manifold pressure and ambient pressure deviate impermissibly from each other.

Abstract: A watercraft has an engine that is controlled by an electronic control unit and the engine is controlled by an electronic throttle. The electronic throttle is actuated by a motor that is controlled by and electronic control unit. The ECU operates the electronic throttle according to a torque request from an operator. The electronic throttle is also periodically and/or at predetermined time intervals actuated to ensure proper operation of the throttle valve.

Abstract: A vehicle electronic control system has a control CPU and a monitor CPU. The control CPU performs a fail-safe processing thereby to reduce an engine output torque, when the monitor CPU monitoring the control CPU detects that the control CPU fails to perform throttle control for an engine. When the monitor CPU detects that the control CPU fails to perform the fail-safe processing, it performs a fail-safe processing in place of the control CPU. In this fail-safe processing, the monitor CPU continues to reset the control CPU so that the engine may be forcibly stopped.

Abstract: In the event that an abnormality is detected in a throttle valve driving apparatus, an upper limit value for a throttle valve opening is set according to a vehicle speed when a brake switch is not switched on. When the brake switch is on, the upper limit value is set at a predetermined idle opening. When the target opening which is calculated according to an accelerator pedal depression amount is larger than the upper limit value, the target opening is changed to the upper limit value.

Abstract: A control system for an internal combustion engine having at least one intake valve and at least one exhaust valve is disclosed. The control system includes a valve operating characteristic varying mechanism and a hydraulic control valve for controlling a hydraulic pressure to be supplied to the valve operating characteristic varying mechanism. The valve operating characteristic varying mechanism continuously varies an operating phase of the at least one intake valve and/or the at least one exhaust valve of the engine. A cleaning operation of the hydraulic control valve is performed in a predetermined operating condition of the engine. An intake air amount of the engine is controlled according to an operating condition of the valve operating characteristic varying mechanism when the cleaning operation of the hydraulic control valve is performed.

Abstract: A method to control the position of a throttle valve in the presence of a fault. The method works independently of throttle position in an open-loop mode. The method assures that the throttle plate will assume the default position if: 1) the return spring is functional and the motor is functional; 2) the return spring has failed but the motor is functional; or 3) if the return spring is functional but the motor has failed. This method does not need to detect loss of return spring functionality and it does not need to detect loss of motor functionality. The detected fault that initiates the action need not be related to either the return spring or the motor.

Abstract: A system for controlling a transmission throttle valve allows the transmission response to be quickly adjusted. The system includes an adapter assembly which is mounted on the rotatable throttle member of a fuel management device. A cam assembly is selectively positionable on the adapter assembly so as to adjust the rate of throttle valve cable pull. The cam assembly has guide pins which move within guide slots on the adapter assembly. The cam assembly also has an adjustment slot which receives an adjustment screw connected to the adapter assembly. The cam assembly is positioned on the adapter assembly so that the adjustment screw occupies a desired location along the adjustment slot, and then the adjustment screw is tightened to lock the cam assembly in place.

Abstract: An apparatus and method for reducing or eliminating wetstacking in internal combustion engine systems operating substantially under capacity comprising establishing an exhaust temperature minimum set point, monitoring exhaust temperature of an engine; and restricting air intake into the engine when the temperature is below the set point. Intake air may also be heated when the exhaust temperature is below the set point, with the intake air divided into first and second paths, the first path being restricted and the second path being heated. The second path preferably comprises a fixed flow choke.

Abstract: An engine control system for monitoring torque increase during cylinder deactivation for a displacement on demand (DOD) engine includes a throttle and a controller. The controller adjusts a preload of the throttle prior to a cylinder deactivation event and determines whether a DOD fault is present during the cylinder deactivation event. The controller one of operates the engine without the preload in the deactivated mode and switches the engine back to the activated mode if the fault is present for a predetermined time. The controller cancels the preload if the DOD fault is present and resets the preload if the predetermined period has not expired. The DOD fault includes one of an engine speed fault, a transmission gear fault and a fueled cylinder fault.

Abstract: A drive control circuit generates a conduction drive output responsive to a detection output of an accelerator pedal depression degree sensor and an air-intake throttle-valve opening sensor, and controls a driving switch element connected to an air-intake throttle-valve opening control motor. A monitoring control circuit drives a control circuit power supply interruption element that closes a control power supply circuit of the driving switch element, and stops control operation of the driving switch element by a conduction-inhibit output. The drive control circuit can stop operation of a power supply interruption element by a feed-inhibit output. At the time of starting operation, a status signal determines activeness of the feed-inhibit output and conduction-inhibit output, after confirming that those outputs are normal, the inhibition is released.

Abstract: An electronic throttle control system is provided, which comprises an accelerator pedal position sensor, a control unit, and a biasing mechanism. The accelerator pedal position sensor detects a position of an accelerator pedal. The throttle actuator actuates a throttle valve to rotate. The control unit determines a target throttle position based on the accelerator pedal position, and controls an operation of the throttle actuator in accordance with the determined target throttle position. The biasing mechanism provides rotational force to the throttle valve such that an opening angle of the throttle valve while the throttle actuator is not powered is greater than a predetermined idle opening angle.

Abstract: A method and an arrangement for controlling an accelerator pedal (1) provide a signal to the driver of a vehicle having an internal combustion engine of the entry into an uneconomical driving pattern via the accelerator pedal. A reset force (FPED) is applied to the accelerator pedal (1). A desired value (FPEDSOLL) for the reset force is increased in dependence upon a drop below a pregiven value for a degree of efficiency of the engine.

Abstract: In a device for restoring a rotary member to a defined basic position, having a three-dimensionally fixed fixation cam that predetermines the basic position and having a slaving cam, which is coupled with the rotary member and is movable past the fixation cam, of which cams, each has one stop face each on sides facing away from one another, and having a clamp spring, which embraces the cams with prestressing by way of two bent-away spring legs, in order to achieve a freedom of play in rotation between the spring legs and the cams in the basic position, at least one spring leg is countersunk, with at least one leg segment, in at least one of the cams so far that in the basic position, with a leg segment fitting over the other cam, it rests without play on the stop face of the other cam.

Abstract: An electronic throttle control system includes an electronic control unit that performs failsafe control for cases where failure of throttle valve is detected, and stores failure information about the throttle valve in a memory 1a so that the failure information can be referenced by an external tool during failure diagnosis, and that initializes the memory 1a when failure diagnosis is complete. The electronic throttle control system further includes a crank angle sensor for detecting engine speed. The electronic control unit initializes the memory that stores failure information relating to electronic control of the throttle valve for cases where an initialization request signal for initializing the memory that stores the throttle valve failure information is inputted from the external tool, and the engine speed that is computed based on the crank angle detected by the crank angle sensor is zero.