METHOD AND SYSTEM FOR DIAGNOSING FAILURE OF A GASOLINE DIRECT INJECTION ENGINE

• US 20150167579A1
• Filed: 06/24/2014
• Published: 06/18/2015
• Est. Priority Date: 12/17/2013
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: KOO, Bon-Chang
• Granted Patent: US 9,523,325 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 2041/389 for injecting directly into the cylinder
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02D 41/38 of the high pressure type
• CPC Class Codes: F02D 41/3854 with elements in the low pressure part, e.g. low pressure pump
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Disclosed are a method and a system for diagnosing failure of a gasoline direct injection (GDI) engine that can diagnose a device (or part) causing failure through forcible driving control of a related device (or part) when failure occurs in the GDI engine. The method for diagnosing failure of a GDI engine may include verifying whether a failure code is output from an engine control unit that controls the engine, and diagnosing whether a fuel system device is in a failure state by forcibly driving the fuel system device of the engine with a set control value when the failure code is output from the engine control unit.

Claims

1. A method for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

verifying whether a failure code is output from an engine control unit that controls the engine; and

diagnosing whether a fuel system device is in a failure state by forcibly driving the fuel system device of the engine with a set control value when the failure code is output from the engine control unit.

2. The method of claim 1, wherein:

the fuel system device includes a fuel pressure sensor, a low-pressure fuel pump, a high-pressure fuel pump, and/or an injector.

3. The method of claim 2, further comprising:

controlling down pressure of the low-pressure fuel pump until the pressure of the low-pressure fuel pump reaches first set down pressure if the failure code is output from the engine control unit;

diagnosing that the fuel pressure sensor is normal if the pressure of the low-pressure fuel pump becomes the first set down pressure;

additionally controlling down the pressure of the low-pressure fuel pump until the pressure of the low-pressure fuel pump becomes second set down pressure;

calculating a change inclination from the first set down pressure to the second set down pressure if the pressure of the low-pressure fuel pump becomes the second set down pressure; and

diagnosing that the low-pressure fuel pump is normal if the change inclination is within a set value range and diagnosing that the low-pressure fuel pump is in the failure state if the change inclination is not within a set value range.

4. The method of claim 3, further comprising:

diagnosing that the fuel pressure sensor is in the failure state if the pressure of the low-pressure fuel pump does not become the first set down pressure even though a down pressure control time of the low-pressure fuel pump is more than a set time.

5. The method of claim 2, further comprising:

controlling the high-pressure fuel pump with a set target maximum pressure value;

calculating an up pressure change inclination until pressure of the high-pressure fuel pump becomes the target maximum pressure value if the pressure of the high-pressure fuel pump becomes the target maximum pressure value; and

diagnosing that the high-pressure fuel pump is normal if the up pressure change inclination is within a set value range and diagnosing that the high-pressure fuel pump is in the failure state if the up pressure change inclination is not within the set value range.

6. The method of claim 2, further comprising:

preventing an operation of the injector;

verifying misfire in a cylinder corresponding to the injector after preventing the operation of the injector; and

diagnosing that the injector is normal if the misfire occurs in the cylinder and diagnosing that the injector is in the failure state if no misfire occurs in the cylinder.

7. The method of claim 2, wherein:

the diagnosing of whether the fuel system device is in the failure state is performed sequentially in an order of the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and the injector.

8. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 1.

9. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 2.

10. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 3.

11. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 4.

12. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 5.

13. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 6.

14. A system for diagnosing failure of a gasoline direct injection (GDI) engine, comprising:

an engine control unit (ECU) configured to control the engine;

a low-pressure fuel pump configured to primarily pressurize gasoline fuel of a fuel tank;

a high-pressure fuel pump configured to secondarily pressurize the fuel pressurized by the low-pressure fuel pump;

an injector configured to directly inject the fuel pressurized by the high-pressure fuel pump into a combustion chamber of the engine;

a fuel pressure sensor configured to detect fuel pressures of the low-pressure fuel pump and the high-pressure fuel pump; and

a failure diagnoser configured to diagnose whether the fuel pressure sensor, the low-pressure fuel pump, the high-pressure fuel pump, and/or the injector are in a failure state if a failure code is output from the engine control unit,

wherein the failure diagnoser executes a command for performing the method of claim 7.