Vehicle engine control device

A vehicle engine control device comprising a transmission in which at least a forward position, a reverse position, a neutral position, and a parking position can be selected by an operation of a selector lever, wherein

• the control device includes a microprocessor, is constructed so as to receive electric supply from an on-vehicle battery through a power supply switch, and includes engine rotational speed detection means for detecting a rotational speed of an engine, fuel injection means for supplying a fuel to the engine, a pair of accelerator position sensors for detecting a depression degree of an accelerator pedal, a pair of throttle position sensors for detecting a throttle valve opening degree of the engine, and drive control means for controlling a driving motor which carries out an opening and closing control of an intake throttle valve in accordance with outputs of the pair of accelerator position sensors and the pair of throttle position sensors, and further includes first non-defective sensor detection means, second non-defective sensor detection means, and escape running means,
• the first non-defective sensor detection means includes first relative abnormality detection means for generating a relative error output when outputs of the pair of accelerator position sensors are mutually compared and a comparison deviation is excessive, and first individual abnormality detection means for detecting existence of a disconnection and a short circuit for each of the pair of accelerator position sensors and generating an individual error output when an abnormality exists, and is means for making a non-defective judgment in such a manner that when both of the pair of accelerator position sensors are not in at least one state of the disconnection and the short circuit, and a relative abnormality does not occur, both the accelerator position sensors are regarded as being non-defective units, and even if the relative abnormality occurs, when one of the accelerator position sensors is in the one state of the disconnection and the short circuit, the other accelerator position sensor is regarded as being a non-defective unit,
• the second non-defective sensor detection means includes second relative abnormality detection means for outputting a relative error output when outputs of the pair of throttle position sensors are mutually compared and a comparison deviation is excessive, and second individual abnormality detection means for detecting existence of a disconnection and a short circuit of each of the pair of throttle position sensors and generating an individual error output when an abnormality exists, and is made means for making a non-defective judgment of the throttle position sensors in such a manner that when both of the pair of throttle position sensors are not in a state of the disconnection and the short circuit, and a relative abnormality does not occur, both the throttle position sensors are regarded as being non-defective units, and even if the relative abnormality occurs, when one of the throttle position sensors is in the state of the disconnection and the short circuit, the other throttle position sensor is regarded as being a non-defective unit, and
• the escape running means is means for carrying out escape driving by the drive control means and the fuel injection control means in response to at least one abnormality of a slightest abnormality due to at least one of a single abnormality of the pair of accelerator position sensors and a single abnormality of the pair of throttle position sensors, a slight abnormality due to both abnormality of the pair of throttle position sensors, and a severe abnormality due to both abnormality of the pair of accelerator position sensors.

A vehicle engine control device using a microprocessor and controlling a driving motor for carrying out an opening and closing control of an intake throttle valve of an engine in accordance with outputs of a pair of accelerator position sensors for detecting a depression degree of an accelerator pedal and outputs of a pair of throttle position sensors for detecting a throttle valve opening degree, the control device including engine rotational speed detection means for detecting a rotational speed of the engine and fuel injection control means for the engine, and further including abnormality detection means, escape running means, and rest cylinder control means, wherein

• the abnormality detection means is means for always monitoring operations of a sensor system, a control system, and an actuator system relating to control of the throttle valve, discriminating between a severe abnormality in which control of the throttle valve is impossible, and a slight abnormality in which control of the throttle valve is possible, and detecting it,
• the escape running means includes at least one of severe abnormality escape running means for controlling the rotational speed of the engine by stopping the control of the throttle valve and by the fuel injection control means, and slight abnormality escape running means for suppressing the rotational speed of the engine by the fuel injection control means while carrying out the control of the throttle valve, and
• the rest cylinder control means is speed control means for increasing or decreasing the number of rest cylinders in which fuel injection is stopped, in accordance with a magnitude of a relative speed deviation between an objective engine rotational speed and an engine rotational speed detected by the engine rotational speed detection means, to obtain the engine rotational speed substantially equal to the objective engine rotational speed.