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Home >> Nissan-Datsun >> 2003 >> Sentra SE-R, Automatic >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 403 (Engine Control System) >> Fuel Pump Circuit >> Diagnostic Procedure >> 4. Check Fuel Pump Power Supply And Ground Circuit For Open And Short
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4. Check Fuel Pump Power Supply And Ground Circuit For Open And Short

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition switch OFF.
  2. Disconnect "fuel level sensor unit and fuel pump" harness connector.
    Fig 1: Identifying Fuel Level Sensor Unit And Fuel Pump Harness Connector
    G00796694Courtesy of NISSAN MOTOR CO., U.S.A.
  3. Disconnect dropping resistor harness connector.
    Fig 2: Identifying Dropping Resistor
    G00796695Courtesy of NISSAN MOTOR CO., U.S.A.
  4. Check harness continuity between

    fuel pump relay terminal 5 and fuel pump terminal 3,

    fuel pump terminal 1 and dropping resistor terminal 2,

    dropping resistor terminal 1 and ground.

    Refer to WIRING DIAGRAM .

    Continuity should exist. 

  5. Also check harness for short to ground and short to power.

OK or NG 

  1. OK: GO TO 6. CHECK FUEL PUMP RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT .
  2. NG: GO TO 5.