An engine ECU executes a control routine including steps of performing output variation control for periodically varying the output of an engine, if control of the engine is not being stopped, at the time of a communication abnormality, and a predetermined time elapses from the time of occurrence of the communication abnormality, and a step of performing fuel-cut control, when the engine speed falls outside a predetermined range.

An oxygen sensor diagnosis control system of a hybrid electric vehicle is provided. The system of a hybrid electric vehicle eliminates an uncertainty of the number of diagnoses of an oxygen sensor and restrains diagnoses of the oxygen sensor in a hybrid electric vehicle. The system of a hybrid electric vehicle includes a hybrid controller operates a vehicle, and determines conversion of an oxygen sensor diagnosis mode based on a result obtained by calculating an oxygen sensor diagnosis index. Additionally, the controller determines whether a condition for diagnosing an oxygen sensor is satisfied when the oxygen sensor diagnosis index decreases to initiate a diagnosis inducing mode or a compulsory diagnosis mode.

An oxygen sensor diagnosis control system of a hybrid electric vehicle is provided. The system of a hybrid electric vehicle eliminates an uncertainty of the number of diagnoses of an oxygen sensor and restrains diagnoses of the oxygen sensor in a hybrid electric vehicle. The system of a hybrid electric vehicle includes a hybrid controller operates a vehicle, and determines conversion of an oxygen sensor diagnosis mode based on a result obtained by calculating an oxygen sensor diagnosis index. Additionally, the controller determines whether a condition for diagnosing an oxygen sensor is satisfied when the oxygen sensor diagnosis index decreases to initiate a diagnosis inducing mode or a compulsory diagnosis mode.

A control method and system for a hybrid vehicle with a DCT is provided. The method includes monitoring whether clutch stuck off is sensed and requesting prohibition of regenerative braking by a driving motor and requesting braking control using mechanical braking force to a higher controller when clutch stuck off is sensed. A driving mode is then changed into a single clutch driving mode, in which a vehicle is driven in gear stages realized by a clutch other than the clutch in which the clutch stuck off occurred and the higher controller is requested to prohibit regenerative braking by the driving motor, when clutch stuck off has occurred. Additionally, the higher controller is requested to obtain the braking force for the vehicle from mechanical braking force is response to determining that single clutch shifting has been performed and braking is required.

A control method and system for a hybrid vehicle with a DCT is provided. The method includes monitoring whether clutch stuck off is sensed and requesting prohibition of regenerative braking by a driving motor and requesting braking control using mechanical braking force to a higher controller when clutch stuck off is sensed. A driving mode is then changed into a single clutch driving mode, in which a vehicle is driven in gear stages realized by a clutch other than the clutch in which the clutch stuck off occurred and the higher controller is requested to prohibit regenerative braking by the driving motor, when clutch stuck off has occurred. Additionally, the higher controller is requested to obtain the braking force for the vehicle from mechanical braking force is response to determining that single clutch shifting has been performed and braking is required.

A drive and control system for a lawn tractor includes a CAN-Bus network, a plurality of controllers, a pair of electric transaxles controlled by the plurality of controllers, and one or more steering and drive input devices coupled to respective sensor(s) for sensing user steering and drive inputs. The plurality of controllers communicate with one or more vehicle sensors via the CAN-Bus network. The plurality of controllers receive the user's steering and drive inputs and posts on the CAN-Bus network and generate drive signals to obtain the desired speed and direction of motion of the lawn tractor.

A drive and control system for a lawn tractor includes a CAN-Bus network, a plurality of controllers, a pair of electric transaxles controlled by the plurality of controllers, and one or more steering and drive input devices coupled to respective sensor(s) for sensing user steering and drive inputs. The plurality of controllers communicate with one or more vehicle sensors via the CAN-Bus network. The plurality of controllers receive the user's steering and drive inputs and posts on the CAN-Bus network and generate drive signals to obtain the desired speed and direction of motion of the lawn tractor.

A vehicle control device include a processor. The processor is configured to monitor a primary power source and a secondary power source for anomalies, the primary power source and the secondary power source supplying electrical power to a plurality of drive devices configured to control deceleration and steering of a vehicle, and in a case in which an anomaly has been detected in at least one of the primary power source or the secondary power source as a result of the monitoring, control the vehicle by supplying electrical power to a drive device having a lower electrical power consumption amount among the plurality of drive devices.

A vehicle control device include a processor. The processor is configured to monitor a primary power source and a secondary power source for anomalies, the primary power source and the secondary power source supplying electrical power to a plurality of drive devices configured to control deceleration and steering of a vehicle, and in a case in which an anomaly has been detected in at least one of the primary power source or the secondary power source as a result of the monitoring, control the vehicle by supplying electrical power to a drive device having a lower electrical power consumption amount among the plurality of drive devices.

A hybrid vehicle includes a first controller configured to output a first control signal for a first inverter, a second controller configured to output a second control signal for a second inverter and a third control signal for the first inverter, and a selection circuit configured to output either of the first control signal or the third control signal to the first inverter. The third control signal is a signal for simultaneously turning on either of upper arm switching elements or lower arm switching elements of a plurality of arms of the first inverter. The second controller starts an engine by outputting the third control signal while outputting the second control signal to drive a second motor generator when abnormality occurs in the first controller.