Abstract: The present disclosure provides a method of diagnosing a failure of a Selective Catalytic Reduction (SCR) system, the method including: injecting urea into the interior of an exhaust pipe using an injector; after the injection step, detecting an amount of NOx and an amount of ammonia through an NOx sensor provided at a rear end of the exhaust pipe; and diagnosing a failure of the injector based on at least one of the amount of NOx and the amount of ammonia.

Abstract: A method and system for controlling breakdown diagnosis are provided. The method includes sensing voltage values of respective batteries applied to a master and a slave via communication between the master and the slave. Additionally, a breakdown diagnosis logic is halted when the sensed battery voltage of the slave is less than a predetermined reference.

Abstract: A method and system for controlling a hybrid vehicle equipped with an air control valve are provided. The method includes collecting road information and determining a number of conversions between an engine operation mode and a motor driving mode based on the collected road information. Further, a degree of flap closing of the air control valve is restricted from being corrected when the predicted number of conversion is less than a predetermined threshold. The air control valve is adjusted for flap displacement upon closing of the flap when the predicted number of conversion is greater than the predetermined threshold and in which the degree of flap closing of the air control valve is corrected based on the detected flap displacement.

Abstract: An apparatus and a method for pre-heating an engine of a mild hybrid vehicle are provided, and the apparatus includes: a pre-heating plug pre-heating the engine; a pre-heating controller recognizing the mild hybrid vehicle based on vehicle driving information, determining whether the mild hybrid vehicle enters a coasting driving mode based on the vehicle driving information, and generating a duty control signal according to a coasting driving time when the mild hybrid vehicle is driven in the coasting driving mode; and a driver supplying electrical energy of the low-voltage battery to the pre-heating plug according to the generated duty control signal.

Abstract: An air flow sensor chip-heating control device and method of a diesel hybrid electric vehicle controls whether an air flow sensor installed in an engine intake system of the diesel hybrid electric vehicle performs a chip-heating operation. Particularly, the air flow sensor chip-heating control device performs a chip heating operation of the air flow sensor based on a result obtained by deciding a driving history of an engine when the vehicle enters into a hybrid mode during driving of the engine.

Abstract: A method for controlling an electricity generation mode of a vehicle includes detecting an idle condition of an engine. An electricity generation mode is performed in which a generator generates an electricity. An idle RPM is increased in the electricity generation mode. An managing mode is entered if the electricity generation mode time elapses a reference time. An engine RPM is increased or decreased for a predetermined time in the managing mode.

Abstract: A method for controlling a fuel pump for a hybrid diesel vehicle may include determining, by a control device, whether to drive the hybrid diesel vehicle in an EV driving mode or in an engine driving mode by reflecting a vehicle driving state information value and stopping, by the control device, operation of a fuel pump relay when the determination is made to drive in the EV driving mode.

Abstract: A method for limiting an engine torque when a failure occurs in a water sensor of a fuel filter includes sensing the failure of the water sensor installed in the fuel filter through a failure diagnosis logic in a diesel hybrid vehicle. A current vehicle driving mode is checked when the failure of the water sensor is sensed. Whether or not a first time period elapses a first delay time after sensing the failure of the water sensor when the current vehicle driving mode is an engine driving mode is determined. The engine torque is limited and reduced when the first time period elapses the first delay time.

Abstract: A method for controlling an air control valve in a diesel hybrid vehicle includes an engine stop detection step for detecting whether a diesel engine is stopped and a vehicle speed is less than a predetermined speed, a first noise and vibration blockade step for controlling a throttle valve to be closed when the diesel engine is stopped and the vehicle speed is less than the predetermined speed, and a first throttle valve control step for closing and then opening again the throttle valve for a predetermined time.

Abstract: A malfunction diagnosis method of a middle door or a step for a vehicle may include: a first receiving step receiving a first operating signal from the middle door or the step of the vehicle; a first diagnosis step of diagnosing whether the middle door or the step is in a failure state based on the first operating signal; a second receiving step of receiving a second operating signal from the middle door or the step of the vehicle; a second diagnosis step of diagnosing whether the middle door or the step is in a failure state based on the second operating signal; determining whether an engine is starting if the first and second diagnosing steps indicate the middle door or the step is in the failure state; and setting an interlock on an accelerator pedal if it is determined that the engine is starting.

Abstract: A system for improving exhaust gas purification performance of a diesel hybrid electric vehicle in which an SCR catalyst is equipped in an exhaust line to reduce nitrogen oxide within exhaust gas may include a hybrid control unit configured to request an engine control unit to turn off an engine to make the diesel hybrid electric vehicle enter a hybrid driving mode, and an engine control unit configured to determine whether urea is required to be injected into a front of the SCR catalyst when receiving a request of an engine off from the hybrid control unit.

Abstract: An air flow sensor chip-heating control device and method of a diesel hybrid electric vehicle controls whether an air flow sensor installed in an engine intake system of the diesel hybrid electric vehicle performs a chip-heating operation. Particularly, the air flow sensor chip-heating control device performs a chip heating operation of the air flow sensor based on a result obtained by deciding a driving history of an engine when the vehicle enters into a hybrid mode during driving of the engine.