Abstract: A solenoid control device executes feedback control such that a drive current for a solenoid follows a target current, by driving, through PWM, a MOSFET provided on a power supply line to the solenoid. An overcurrent detection circuit that outputs an overcurrent detection signal when the drive current for the solenoid reaches an overcurrent determination current value is provided, and it is determined whether an overcurrent is generated. Whether a short-circuit occurs between both terminals of the solenoid is determined by monitoring whether the overcurrent detection circuit is repeating an output of the overcurrent detection signal and a stop of the output of the overcurrent detection signal.

Abstract: A drive force distribution control apparatus in which if a relay output voltage (Vah) detected by relay-output-voltage detecting means (30) is lower than a first threshold, the relay is repeatedly and successively turned on and off multiple times, and then if the relay output voltage (Vah) detected later by the relay-output-voltage detecting means (30) while an engine speed (Er) is higher than a second threshold and an ignition switch (IG) is on is still lower than the first threshold, it is determined that there is an abnormality that keeps the relay stuck open, and then control for switching the drive mode from a four-wheel-drive mode to a two-wheel-drive mode is executed.

Abstract: A driving force distribution control device controls an inductive load circuit to adjust a ratio of driving forces transmitted from a driving source to a plurality of wheels via a driving force transmitting system. The driving force distribution control device counts a number of tests performed by applying a test current to the inductive load circuit; determines that a disconnecting abnormality occurs in an electric load including the inductive load circuit if a difference between a value of the test current and a value of current flowing in the inductive load circuit is greater than a current difference threshold value; and determines that the disconnecting abnormality is definitive if the number of tests is equal to a threshold value or more, and also if the number of determinations of the disconnecting abnormality is equal to a predetermined threshold value or more.

Abstract: A solenoid control device executes feedback control such that a drive current for a solenoid follows a target current, by driving, through PWM, a MOSFET provided on a power supply line to the solenoid. An overcurrent detection circuit that outputs an overcurrent detection signal when the drive current for the solenoid reaches an overcurrent determination current value is provided, and it is determined whether an overcurrent is generated. Whether a short-circuit occurs between both terminals of the solenoid is determined by monitoring whether the overcurrent detection circuit is repeating an output of the overcurrent detection signal and a stop of the output of the overcurrent detection signal.

Abstract: A drive force distribution control apparatus in which if a relay output voltage (Vah) detected by relay-output-voltage detecting means (30) is lower than a first threshold, the relay is repeatedly and successively turned on and off multiple times, and then if the relay output voltage (Vah) detected later by the relay-output-voltage detecting means (30) while an engine speed (Er) is higher than a second threshold and an ignition switch (IG) is on is still lower than the first threshold, it is determined that there is an abnormality that keeps the relay stuck open, and then control for switching the drive mode from a four-wheel-drive mode to a two-wheel-drive mode is executed.

Abstract: A hunting detecting device used for an electrical load detecting device sets a current command value for an electrical load. Based on a deviation between a current that actually flows through the electrical load and the current command value, the hunting detecting device performs at least proportional control in a group including proportional control, integral control, and differential control. The hunting detecting device sends a current generated based on the performed control to the electrical load. A current determining device determines whether there is a current through the electrical load. When the current determining device determines that there is a current through the electrical load, a hunting detector detects a number of times of hunting within a predetermined period.

Abstract: The four-wheel-drive vehicle has a torque transmission device configured to distribute torque transmitted from an engine to a first set of wheels to a second set of wheels. Throttle-opening of the engine is detected. A first torque command which depends on the throttle-opening is obtained. A rotational speed difference between the first set of wheels and the second set of wheels is detected. A second torque command which depends on the rotational speed difference is obtained. The torque transmission device is controlled based on the first and the second torque command so as to transmit the driving force to the second set of wheels according to the throttle-opening and the rotational speed difference. Then, a signal that corresponds to the throttle-opening is monitored. When the signal is judged being abnormal, the first torque command is ignored so that the torque transmission device is controlled based on the second torque command.

Abstract: A torque distribution control device for a four-wheel drive vehicle has a torque distribution device for distributing the drive power transmitted from an engine to either of the front wheels or the rear wheels as prime drive wheels, to other wheels as sub-drive wheels. The control device judges whether or not an abnormality is involved in wheel speed signals which are input from wheel speed sensors associated respectively with the front and rear wheels. A normal-state method of calculating a command torque which is applied to the torque distribution device to vary the drive power transmitted to the sub-drive wheels, is then altered to an abnormal-state method of calculating the command torque based on data which does not include one wheel speed signal involving the abnormality when the same occurs with one of the wheel speed signals, whereby the vehicle is enabled to continue the four-wheel drive even when the abnormality occurs.

Abstract: A hunting detecting device used for an electrical load detecting device sets a current command value for an electrical load. Based on a deviation between a current that actually flows through the electrical load and the current command value, the hunting detecting device performs at least proportional control in a group including proportional control, integral control, and differential control. The hunting detecting device sends a current generated based on the performed control to the electrical load. A current determining device determines whether there is a current through the electrical load. When the current determining device determines that there is a current through the electrical load, a hunting detector detects a number of times of hunting within a predetermined period.

Abstract: The four-wheel-drive vehicle has a torque transmission device configured to distribute torque transmitted from an engine to a first set of wheels to a second set of wheels. Throttle-opening of the engine is detected. A first torque command which depends on the throttle-opening is obtained. A rotational speed difference between the first set of wheels and the second set of wheels is detected. A second torque command which depends on the rotational speed difference is obtained. The torque transmission device is controlled based on the first and the second torque command so as to transmit the driving force to the second set of wheels according to the throttle-opening and the rotational speed difference. Then, a signal that corresponds to the throttle-opening is monitored. When the signal is judged being abnormal, the first torque command is ignored so that the torque transmission device is controlled based on the second torque command.

Abstract: A torque distribution control device for a four-wheel drive vehicle is disclosed having a torque distribution device for distributing the drive power transmitted from an engine to either of the front wheels or the rear wheels as prime drive wheels, to other wheels as sub-drive wheels. In the control device, abnormality judgment means judges whether or not an abnormality is involved in wheel speed signals which are input from wheel speed sensors associated respectively with the front and rear wheels. Means is further provided for altering a normal-state method of calculating a command torque which is applied to the torque distribution device to vary the drive power transmitted to the sub-drive wheels, to an abnormal-state method of calculating the command torque based on data which does not include one wheel speed signal involving the abnormality when the same occurs with one of the wheel speed signals, whereby the vehicle is enabled to continue the four-wheel drive even when the abnormality occurs.

Abstract: In a process of producing a SiC device, a Si layer is formed on the surface of a SiC substrate, and the Si layer is removed from the surface of the SiC substrate by supplying oxygen gas to the Si layer in a high ambient temperature and a low ambient pressure. The pressure is set at 1×10−2 to 1×10−6 Pa. Thus a cleaned surface of the SiC substrate, not contaminated by carbon and the like in atmospheric air, can be provided. Preferably, the oxygen pressure and temperature are set at about 10−6 Pa and 1000° C. for removing the Si layer. Thereafter, the oxygen is further supplied to raise the pressure to about 104 Pa to form an oxide film on the cleaned SiC substrate. Thus, the SiC substrate is cleaned and then formed with the oxide layer in the same chamber by changing the ambient pressure but without changing the ambient temperature.

Abstract: In a process of producing a SiC device, a Si layer is formed on the surface of a SiC substrate, and the Si layer is removed from the surface of the SiC substrate by supplying oxygen gas to the Si layer in a high ambient temperature and a low ambient pressure. The pressure is set at 1×10−2 to 1×10−6 Pa. Thus a cleaned surface of the SiC substrate, not contaminated by carbon and the like in atmospheric air, can be provided. Preferably, the oxygen pressure and temperature are set at about 10−6 Pa and 1000° C. for removing the Si layer. Thereafter, the oxygen is further supplied to raise the pressure to about 104 Pa to form an oxide film on the cleaned SiC substrate. Thus, the SiC substrate is cleaned and then formed with the oxide layer in the same chamber by changing the ambient pressure but without changing the ambient temperature.