A method, for an internal combustion engine including an intake camshaft equipped with a variable intake valve timing device including an intake timing actuator and an exhaust camshaft equipped with a variable exhaust valve timing device including an exhaust timing actuator, of detecting inverted connection of the intake timing actuator with the exhaust timing actuator, including: measuring the angular position of the intake camshaft and the angular position of the exhaust camshaft; commanding one of the two timing actuators according to a setpoint and keeping the other of the two timing actuators immobile; measuring the angular positions of the intake camshaft and of the exhaust camshaft; and comparing: if the angular position of the camshaft corresponding to the timing actuator that's been commanded has not been modified, and if the angular position of the camshaft corresponding to the immobile timing actuator has been modified, inverted connection can be diagnosed.

With a simple configuration, responsiveness between an electronic control unit and a load drive circuit is monitored without deteriorating characteristics of the load drive circuit. The load drive circuit according to the present invention diagnoses an abnormality in responsiveness of a switch element that drives a load based on a drive command of the switch element and a signal at an output terminal of the switch element.

Provided is an injector control unit capable of preventing unintended fuel injection other than an engine drive period. The injector control unit includes a cutoff mechanism for cutting off current supply to the injector from at least the ignition OFF to the next ignition ON.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

The subject matter of this specification can be embodied in, among other things, a method that includes evaluating an analog electrical current waveform, determining a Boolean waveform based on the evaluated analog electrical current waveform, determining a collection of one or more first durations based on one or more on times identified from the Boolean waveform, determining a collection of one or more second durations based on one or more off times identified from the Boolean waveform, comparing the first durations and the second durations, determining, based on the comparing, an event based on the comparing, identifying a time at which the event occurred, and providing the time as a completion time.

Provided is a load drive device for controlling a fuel injection device for a vehicle engine and capable of checking an operation of the fuel injection device with high reliability without actually injecting fuel before starting the engine. The load drive device includes: a first switching element that is connected to a high-side of a load; a second switching element that is connected to a low-side of the load; a pre-driver circuit that transmits a drive instruction to the first switching element and the second switching element; and an arithmetic device that transmits a control instruction to the pre-driver circuit, in which a first monitor line and the second monitor line are connected to the arithmetic device, the first monitor line monitoring the drive instruction from the pre-driver circuit to the first switching element before starting an engine, and the second monitor line monitoring the drive instruction from the pre-driver circuit to the second switching element, and the pre-driver circuit has a first control mode in which the first switching element is turned off and the drive instruction is transmitted to the second switching element, and a second control mode in which the second switching element is turned off and the drive instruction is transmitted to the first switching element.

A fuel injection valve drive control device includes a boost circuit having a boost coil, a switching component (FFT or the like) supplying a switching current from a battery source voltage to the boost coil, and a boost capacitor accumulating a boosted voltage generated by the operation of the switching component; a discharge circuit for discharging the accumulated electric charge via a current limiter (e.g. discharge resistor, constant current source) and a discharge switch (FET or the like); and a monitoring circuit for monitoring the accumulated voltage. The discharge circuit is caused to operate when the control device is shutting down and performs a deterioration/failure diagnosis of the boost capacitor and an operation check of the discharge circuit on the basis of a monitored voltage value of the boost capacitor at starting the discharge operation and a monitored voltage value of the boost capacitor after a predetermined time has elapsed.

A device and a method for checking switch-off paths in control units of internal combustion engines during ongoing engine operation.

A device and a method for checking switch-off paths in control units of internal combustion engines during ongoing engine operation.

Appropriate detection of an abnormality of voltage information, which is a basis for correcting a fuel injection amount, becomes possible. For this reason, a fuel injection control device 127, which has a drive IC 208 controlling a fuel injection drive unit 207a to supply a high voltage to a solenoid 405 so as to open a fuel injection valve 105 and controlling the fuel injection drive unit 207a to supply a low voltage to the solenoid 405 so as to hold a valve-open state of the fuel injection valve 105, includes: a drive voltage input unit 211 that measures and outputs voltage information based on an upstream voltage of the solenoid 405 of the fuel injection valve 105 and a downstream voltage of the solenoid 405; a fuel injection amount correction unit 213 that corrects a fuel injection amount of the fuel injection valve 105 based on the voltage information output from the drive voltage input unit 211; and a voltage input function abnormality detection unit 212 that detects whether an output of the drive voltage input unit 211 is abnormal based on the voltage information output from the drive voltage input unit 211.