Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Other

Hideki Miyahara

Tokiji Ito

Kenji Nagasaki

Keita Fukui

Takumi Anzawa

Yuusaku Nishimura

Akihiro Katayama

Yasuo Kato

Masao Kano

Akira Ichikawa

Yuki Ikejiri

Shuichi Hanai

Kenichiro Kawase

Hirotaka Nakayama

Shogo Chikada

A leak diagnosis device for a fuel vapor treatment apparatus, comprising: a first diagnosis unit that performs a leak diagnosis of a fuel tank based on a tank internal pressure in a closed state of a sealing valve; a determination unit that opens a sealing valve in a state where a purge valve and a switching valve are closed when the tank internal pressure is within a normal range, and determines whether there is an influence on the valve openability of the switching valve; and a second diagnosis unit that performs a leak diagnosis of the canister based on the tank internal pressure or the canister internal pressure when the determination unit makes a negative determination, and performs a leak diagnosis of the canister based on the canister internal pressure after closing the closed valve when the determination unit makes an affirmative determination.

Leak diagnosis device of fuel vapor treatment apparatus

The fuel vapor treatment apparatus includes a fuel tank, a canister, a vapor passage, a purge passage, a sealing valve, a purge valve, an outside air introduction passage, a switching valve, and a differential pressure detector. A processing device of the fuel vapor treatment apparatus includes a purge control unit and a purge diagnosis unit. The purge control unit performs a purge process by opening the purge valve in a state where the purge valve and the sealing valve are closed and the switching valve is opened. The purge diagnosis unit diagnoses whether or not the purge process is normal based on the amount of change in the differential pressure between before and after the opening of the purge valve.

Control device for fuel vapor treatment apparatus

A diagnostic device is configured to execute a first acquisition process of acquiring a remaining amount of evaporated fuel in a fuel tank when an ignition switch turns off, as an end remaining amount, a determination process of, after the first acquisition process, determining whether there is a blockage of a vapor passage by reducing a pressure in a vapor passage with a pressure reducing pump when the end remaining amount is smaller than a prescribed value while the ignition switch is off, a second acquisition process of, after the determination process, acquiring a remaining amount of liquid fuel in the fuel tank when the ignition switch turns on, as a start remaining amount, and an invalidation process of invalidating a determination result that a blockage is present in the vapor passage in the determination process when the start remaining amount is larger than or equal to a set value.

Diagnostic system for evaporated fuel treatment system

An abnormality diagnosis apparatus performs a stop process for stopping the supply of fuel to at least one of a plurality of cylinders and supplying fuel to the other cylinders or cylinder. The abnormality diagnosis apparatus performs a catalyst abnormality diagnosis process for diagnosing that there is an abnormality in an exhaust gas control apparatus, based on the value of a first misfire counter indicating the number of times of detection of a misfire during the operation of an internal combustion engine by a prescribed amount. In the catalyst abnormality diagnosis process, the abnormality diagnosis apparatus diagnoses that there is an abnormality in the exhaust gas control apparatus with the value of the first misfire counter being smaller when the stop process is performed than when the stop process is not performed during the operation of the internal combustion engine by the prescribed amount.

Abnormality diagnosis apparatus for internal combustion engine

A diagnosis device for an engine, the diagnosis device includes an electronic control unit. The electronic control unit is configured to execute EGR diagnosis processing to diagnose whether or not the EGR device operates normally while a vehicle is being decelerated, execute air flow meter diagnosis processing to diagnose whether or not the air flow meter is normal while the vehicle is decelerated, execute the EGR diagnosis processing after starting the air flow meter diagnosis processing, and execute the EGR diagnosis processing when the air flow meter diagnosis processing has not been completed and predetermined conditions that a duration of deceleration of the vehicle being shorter than a diagnosis time that is required to execute the air flow meter diagnosis processing are fulfilled.

Diagnosis device for internal combustion engine, and diagnosis method for internal combustion engine

An abnormality determining apparatus of a fuel vapor processing system is provided. The system includes a canister for temporarily reserves fuel vapor generated within a fuel tank and a fuel vapor path for discharging the fuel vapor to an engine intake passage. When it is determined that there is a leak abnormality in the fuel vapor path, a pump is operated to discharge air from the fuel vapor path to the outside through the canister. When the pump is operated, a detector detects a pressure in the fuel vapor path as an actually measured pressure. A determining section determines whether there is a leak abnormality. The determining section sets a first determination pressure and a second determination pressure that is higher than the first determination pressure. The determining section determines that there is no leak abnormality either when a first condition is met or when a second condition is met. The first condition indicates that the actually measured pressure is less than or equal to the first determination pressure, and the second condition indicates that the actual measured pressure when changes due to the operation of the pump have subsided is less than or equal to the second determination pressure. The determining section determines that there is a leak abnormality when none of the first condition nor the second condition is met.

Abnormality determining apparatus of fuel vapor processing system

A cooling apparatus includes a thermostat that adjusts a feed rate of coolant to a radiator, estimating means that estimates a coolant temperature simulated value at least based on the detection value of an intake-air temperature sensor, and diagnosis means that diagnoses an operating state of the thermostat by comparing the detection value of a coolant temperature sensor, and the coolant temperature simulated value when a diagnosis condition is established. When a ratio of an integrated value of the simulated water temperature variation in an idle state to the integrated value of the simulated water temperature variation in a normal driving state is equal to or greater than an upper limit ratio XP, the diagnosis of the operating state of the thermostat is prohibited.

Cooling apparatus for internal combustion engine

A cooling apparatus for an engine is provided with a thermostat operating in such a manner as to control a supply of a coolant to a radiator. An electronic control apparatus estimates a reference temperature corresponding to a temperature of the coolant on the basis of at least a vehicle speed, and diagnoses an operating state of the thermostat on the basis of a comparison between a detected value of the coolant temperature and the reference temperature. The electronic control apparatus inhibits the diagnosis of the operating state of the thermostat in the case that any one of the following conditions i) to iii) is satisfied.

Cooling apparatus for internal combustion engine and diagnosis method for the cooling apparatus

A suction pump introduces negative pressure into a reference-pressure-detecting portion. A driving voltage V of the suction pump is adjusted in such a manner that pressure Pr in the reference-pressure-detecting portion is within a target pressure range. When the pressure Pr is brought into the target pressure range, the driving voltage V of the suction pump is stored as a first driving voltage Vand the pressure Pr is stored as a reference pressure Pr. When pressure detection and leak detection process are conducted, the suction pump is driven at the first driving voltage Vto introduce the negative pressure. The computer compares the pressure Pr with a leak determination value to determine whether a leak exists.

Leak detector for fuel vapor purge system

After a reference pressure using a reference hole is measured, a pressure in an evaporation path is measured. An ECU conducts failure diagnosis using, as a determination pressure for diagnosing presence/absence of a failure, a value obtained by correcting the reference pressure using the reference hole in a manner lowering the same by a predetermined amount, taking into account pressure lowering in the evaporation path due to condensation of fuel vapor at the time of adsorption in a canister when a vapor concentration in the evaporation path is high.

Failure diagnostic apparatus for fuel vapor purge system and fuel vapor purge apparatus and combustion engine having failure diagnostic apparatus

When a purge amount while an engine is running is a first purge amount and the purge amount before failure diagnosis is larger than a required purge amount, an amount adsorbed in a canister before the failure diagnosis is executed is smaller than a predetermined determination value. Accordingly, an ECU executes the failure diagnosis. When the purge amount while the engine is running is a second purge amount and the purge amount before the failure diagnosis is equal to or smaller than the required purge amount, the amount adsorbed in the canister before the failure diagnosis is equal to or larger than the predetermined determination value. Accordingly the ECU does not execute the failure diagnosis. The required purge amount used for determining whether or not the failure diagnosis can be executed is determined according to the temperature before the failure diagnosis.

A fuel vapor purge system includes a fuel tank, a canister, and an evaporation route, and purges fuel vapor collected in the canister into an intake passage of an internal combustion engine. A failure diagnosis apparatus of the fuel vapor purge system includes a controller having a pressure difference applying unit for applying a pressure difference between the evaporation route and outside air. The controller also detects a level of an influence of the fuel vapor generated in the fuel tank on failure determination of the evaporation route, and detects both a pressure state obtained when the pressure difference applying unit communicates with a reference orifice communicating with the outside air and a pressure state obtained when the pressure difference applying unit communicates with the evaporation route. The failure diagnosis apparatus determines whether there is a failure in the evaporation route in view of the level of the influence by comparing the detected pressure states with each other.

Apparatus and method for failure diagnosis of fuel vapor purge system

When detection of an abnormality in a fuel vapor treating system is executed, a vapor zone including a fuel tank and a canister is sealed. The sealed vapor zone is pressurized. Whether fuel vapor is leaking from the vapor zone is determined based on the pressure in the sealed vapor zone. A canister valve selectively connects a canister with and disconnects the canister from the atmosphere. During the abnormality detecting procedure, an electronic control unit (ECU) shuts the canister valve. After the abnormality detecting procedure is ended, the ECU sends a control signal having a predetermined frequency to the canister valve, thereby gradually increasing the opening size of the canister valve. Accordingly, the pressure in the vapor zone is gradually lowered to the atmospheric pressure. This prevents fuel vapor adsorbed by the canister from being released to the atmosphere.

Growing community of inventors

Nishikamo-gun, Japan

Hideki Miyahara