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|1. (WO2018159494) DEVICE FOR DIAGNOSING FUEL SUPPLY SYSTEM FOR INTERNAL COMBUSTION ENGINE|
|Applicants:||HITACHI AUTOMOTIVE SYSTEMS, LTD.
|Title:||DEVICE FOR DIAGNOSING FUEL SUPPLY SYSTEM FOR INTERNAL COMBUSTION ENGINE|
Provided is a device for diagnosing a fuel supply system of an internal combustion engine, said device diagnosing whether or not a fuel supply system for supplying fuel in a fuel tank to a fuel injection valve of the internal combustion engine by means of a fuel pump is functioning abnormally (is damaged). When a request to start-up the internal combustion engine is generated, the device causes the fuel pump to operate for a predetermined time such that the actual fuel pressure (actual fuel pressure) of the fuel supply system reaches a target fuel pressure (target fuel pressure) before the internal combustion engine is started up, and diagnoses whether or not the fuel supply system is suffering from fuel leakage by comparing a rate of drop in the actual fuel pressure after the fuel pump is stopped when the predetermined time has passed with a pre-stored rate of drop in the actual fuel pressure at normal times. When the diagnosis indicates that the fuel supply system is suffering from a fuel leakage, the request to start-up the internal combustion engine is canceled, thereby restricting the internal combustion engine from being started up.