| 摘要 |
PROBLEM TO BE SOLVED: To provide malfunction diagnosing device capable of obtaining diagnosing result with high reliability, capable of specifying malfunction sites even though multiple malfunctions are generated. SOLUTION: An engine is determined to be normal when fuel pressure lowers around the set pressure of a pressure regulator and the pressure around the set pressure is kept and fuel leakage is determined when pressure down is continued to lower to a pressure not more high than the set pressure when making pump drive duty ratio 0% along with the turning off of the engine switch. On the other hand, a pump relay is turned off in the case the fuel pressure is kept in the pressure more than the set pressure, the a short malfunction of the fuel pump is determined to be generated when the fuel pressure lowers around the set pressure, and the fuel leakage is determined to be generated when the fuel pressure continues to lower not more than the set pressure, when making the pump drive duty ratio 0%. While, a closed fixing malfunction of the pressure regulator is determined to be generated in the case the pressure does not lower around the set value despite turning off the pump relay, and further the fuel leakage is determined to be generated in the case pressure down is continued thereafter. COPYRIGHT: (C)2013,JPO&INPIT |
