Abstract: An EGR device for a vehicle includes a valve driver, a pressure comparison unit, a freeze determination unit, and an EGR controller. The valve driver drives an EGR valve to open, when fuel cut has been continued for a predetermined time in a state where an engine speed of a vehicle's engine is equal to or higher than a predetermined rotational speed. The pressure comparison unit compares a pre-driving pressure of an engine's intake pipe with a post-driving pressure of the intake pipe. The freeze determination unit sets a flag indicating that the EGR valve is frozen when a difference between the pre-driving pressure and the post-driving pressure is less than a predetermined value and an external temperature is less than a threshold. When the flag has been set, the EGR controller sets a control state of the EGR valve to a closed state and stops EGR control.

Abstract: A diagnostic apparatus for an evaporative fuel processing system includes a fuel tank retaining fuel to be fed to a pressure-charger-equipped engine, a canister communicating with the fuel tank and adsorbing evaporative fuel generated therein, an upstream purge line allowing the canister and an engine intake system to communicate at an upstream side of the pressure charger, an upstream purge valve that opens and closes the upstream purge line, a pressure detector detecting pressure in the upstream purge line; a valve controller that opens and closes the upstream purge valve during pressure-charging and non-pressure-charging, respectively, a first timekeeper measuring an accumulative time in which a diagnosis execution condition is satisfied after a purge-flow diagnosis is started, and a determiner determining that the system operates normally or abnormally depending on whether the pressure decreases or not by a predetermined pressure or more from the start of the diagnosis.

Abstract: An EGR device for a vehicle includes a valve driver, a pressure comparison unit, a freeze determination unit, and an EGR controller. The valve driver drives an EGR valve to open, when fuel cut has been continued for a predetermined time in a state where an engine speed of a vehicle's engine is equal to or higher than a predetermined rotational speed. The pressure comparison unit compares a pre-driving pressure of an engine's intake pipe with a post-driving pressure of the intake pipe. The freeze determination unit sets a flag indicating that the EGR valve is frozen when a difference between the pre-driving pressure and the post-driving pressure is less than a predetermined value and an external temperature is less than a threshold. When the flag has been set, the EGR controller sets a control state of the EGR valve to a closed state and stops EGR control.

Abstract: A diagnostic apparatus includes a fuel tank; a canister adsorbing evaporative fuel; an upstream purge line allowing the canister and an engine intake system to communicate upstream of a pressure charger; an upstream purge valve that opens and closes the upstream purge line; a pressure detector detecting pressure in the upstream purge line; a valve controller that opens and closes the upstream purge valve during pressure-charging and non-pressure-charging; a timekeeper measuring an accumulative time in which a diagnosis execution condition is satisfied after a purge-flow diagnosis starts; and a determiner determining whether evaporative fuel processing system operates normally or abnormally depending on whether the pressure decreases by a predetermined pressure or more from the start of the diagnosis. Every time the upstream purge valve opens after the condition is satisfied, the timekeeper measures the accumulative time after a predetermined delay time elapses from when a valve opening command is output.

Abstract: A purge system malfunction diagnosis device is configured to diagnose a malfunction in a purge system mounted on a vehicle. The purge system includes a canister, a purge passage, a purge valve capable of opening and closing the purge passage, an outside air passage configured to cause the canister to communicate with an outside air opening, an outside air valve capable of opening and closing the outside air passage, and a system pressure sensor configured to detect a pressure in the purge system. In a state where the outside air passage is closed, a diagnosis mode is executed on a basis of a relationship between the pressure in the purge system and an integrated value of flow rate estimates of a purge gas. In the diagnosis mode, a parameter to be used for diagnosing a malfunction in the purge system is adjusted in a case where the flow rate estimate is lower than a flow rate threshold.

Abstract: A purge system malfunction diagnosis device is configured to diagnose a malfunction in a purge system mounted on a vehicle configured to execute an idling stop control. The system includes a canister, a purge passage, a purge valve capable of opening and closing the purge passage, an outside air passage that causes the canister to communicate with an outside air opening, an outside air valve capable of opening and closing the outside air passage by being driven using an electric power supplied from a battery, and a system pressure sensor that detects a pressure in the purge system. In a state where the outside air passage is closed, a diagnosis mode is executed on a basis of a relationship between the pressure in the purge system and an integrated value of flow rate estimates of a purge gas, and the diagnosis mode is prohibited on a basis of a voltage of the battery.

Abstract: A diagnostic apparatus includes a fuel tank; a canister adsorbing evaporative fuel; an upstream purge line allowing the canister and an engine intake system to communicate upstream of a pressure charger; an upstream purge valve that opens and closes the upstream purge line; a pressure detector detecting pressure in the upstream purge line; a valve controller that opens and closes the upstream purge valve during pressure-charging and non-pressure-charging; a timekeeper measuring an accumulative time in which a diagnosis execution condition is satisfied after a purge-flow diagnosis starts; and a determiner determining whether evaporative fuel processing system operates normally or abnormally depending on whether the pressure decreases by a predetermined pressure or more from the start of the diagnosis. Every time the upstream purge valve opens after the condition is satisfied, the timekeeper measures the accumulative time after a predetermined delay time elapses from when a valve opening command is output.

Abstract: A diagnostic apparatus for an evaporative fuel processing system includes a fuel tank retaining fuel to be fed to a pressure-charger-equipped engine, a canister communicating with the fuel tank and adsorbing evaporative fuel generated therein, an upstream purge line allowing the canister and an engine intake system to communicate at an upstream side of the pressure charger, an upstream purge valve that opens and closes the upstream purge line, a pressure detector detecting pressure in the upstream purge line; a valve controller that opens and closes the upstream purge valve during pressure-charging and non-pressure-charging, respectively, a first timekeeper measuring an accumulative time in which a diagnosis execution condition is satisfied after a purge-flow diagnosis is started, and a determiner determining that the system operates normally or abnormally depending on whether the pressure decreases or not by a predetermined pressure or more from the start of the diagnosis.

Abstract: A purge system malfunction diagnosis device is configured to diagnose a malfunction in a purge system mounted on a vehicle configured to execute an idling stop control. The system includes a canister, a purge passage, a purge valve capable of opening and closing the purge passage, an outside air passage that causes the canister to communicate with an outside air opening, an outside air valve capable of opening and closing the outside air passage by being driven using an electric power supplied from a battery, and a system pressure sensor that detects a pressure in the purge system. In a state where the outside air passage is closed, a diagnosis mode is executed on a basis of a relationship between the pressure in the purge system and an integrated value of flow rate estimates of a purge gas, and the diagnosis mode is prohibited on a basis of a voltage of the battery.

Abstract: A purge system malfunction diagnosis device is configured to diagnose a malfunction in a purge system mounted on a vehicle. The purge system includes a canister, a purge passage, a purge valve capable of opening and closing the purge passage, an outside air passage configured to cause the canister to communicate with an outside air opening, an outside air valve capable of opening and closing the outside air passage, and a system pressure sensor configured to detect a pressure in the purge system. In a state where the outside air passage is closed, a diagnosis mode is executed on a basis of a relationship between the pressure in the purge system and an integrated value of flow rate estimates of a purge gas. In the diagnosis mode, a parameter to be used for diagnosing a malfunction in the purge system is adjusted in a case where the flow rate estimate is lower than a flow rate threshold.