초록 ▼

An on-board diagnostic system for performing a diagnostic test on a fuel delivery system. The diagnostic system is controlled by a controller such as a powertrain control module or an electronic engine controller. With the engine off and key on, fuel is delivered to the engine\s fuel rail. A standar

An on-board diagnostic system for performing a diagnostic test on a fuel delivery system. The diagnostic system is controlled by a controller such as a powertrain control module or an electronic engine controller. With the engine off and key on, fuel is delivered to the engine\s fuel rail. A standard, production pressure sensor in fluid communication with the fuel rail records the pressure in the fuel delivery system. The recorded pressure is then compared to a stored acceptable pressure range to determine whether the fuel delivery control means is delivering fuel to the fuel rail and whether the fuel delivery system is holding pressure. Each fuel injector is then actuated for a specified time. When the injector is actuated, the fuel pressure drop sensed by the pressure sensor is compared to a stored pressure drop range to determine whether the injector is faulty. The test can only be performed a limited number of times before the engine must be turned on to burn off excess fuel to prevent both catalyst damage and hydrostatic lockup of the engine.

대표청구항 ▼

A diagnostic system for performing a diagnostic test on a fuel delivery system of an internal combustion engine while the engine is off, the fuel delivery system comprising: a plurality of fuel injectors in fluid communication with the engine for supplying fuel to the engine; a fuel rail in fluid co

A diagnostic system for performing a diagnostic test on a fuel delivery system of an internal combustion engine while the engine is off, the fuel delivery system comprising: a plurality of fuel injectors in fluid communication with the engine for supplying fuel to the engine; a fuel rail in fluid communication with said injectors; a fuel delivery control means to selectively deliver fuel to said fuel rail; and, a pressure sensor in fluid communication with said fuel rail for sensing pressure in said fuel delivery system during normal operation of the engine, as well as during said diagnostic test, the diagnostic system comprising: a controller means for performing said diagnostic test comprising: a fuel delivery actuation means for actuating said fuel delivery control means; a fuel injector actuation means for actuating at least one said injector for a predetermined time period; a storage means for storing an acceptable fuel pressure drop range; a comparison means for comparing a fuel pressure in said fuel delivery system sensed by said pressure sensor during said time period to said stored acceptable fuel pressure drop range; a signaling means for signaling the results of said test comprising which of said injectors, upon actuation thereof, causes said fuel pressure in said fuel delivery system sensed during said time period to be outside said acceptable fuel pressure drop range; and, a test prohibiting means for prohibiting a further test from occurring before requiring the engine to be started if a predetermined number of tests have been performed.