Diagnosis Procedure

Regarding Wiring Diagram information, refer to "WIRING DIAGRAM-ENGINE CONTROL SYSTEM- ".

1. INSPECTION START

   Confirm the detected malfunction (A or B). Refer to "DTC LOGIC ".

   Which malfunction is detected? 

   A: GO TO 2.

   B: GO TO  7.

2. CHECK GROUND CONNECTION
   1. Turn ignition switch OFF.
   2. Check ground connection E9. Refer to Ground Inspection in "CIRCUIT INSPECTION ".

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Repair or replace ground connection.

3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
   1. Turn ignition switch OFF.
   2. Disconnect "fuel level sensor unit and fuel pump" harness connector.
   3. Turn ignition switch ON.
   4. Check the voltage between "fuel level sensor unit and fuel pump" harness connector and ground.

      Fuel level sensor unit and fuel pump		Ground	Voltage
      Connector	Terminal
      B42	4	Ground	Approx. 5 V

      Fig 1: Checking Voltage Between Fuel Level Sensor Unit And Fuel Pump Terminal 4 And Ground

      Courtesy of NISSAN NORTH AMERICA, INC.

      Is the inspection result normal? 

      YES: GO TO  5.

      NO: GO TO 4.

4. DETECT MALFUNCTIONING PART

   Check the following.

   • Harness connectors B10, E29
   • Harness for open or short between ECM and "fuel level sensor unit and fuel pump"

     : Repair open circuit, short to ground or short to power in harness or connector.

5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
   1. Turn ignition switch OFF.
   2. Disconnect ECM harness connector.
   3. Check the continuity between "fuel level sensor unit and fuel pump" harness connector and ECM harness connector.

      Fuel level sensor unit and fuel pump		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      B42	5	E10	104	Existed

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

      Is the inspection result normal? 

      YES: GO TO  7.

      NO: GO TO 6.

6. DETECT MALFUNCTIONING PART

   Check the following.

   • Harness connectors B1, M6
   • Harness connectors E30, M1
   • Harness for open or short between "fuel level sensor unit and fuel pump" and ECM

     : Repair open circuit, short to ground or short to power in harness or connector.

7. CHECK FUEL TANK TEMPERATURE SENSOR

   Refer to "COMPONENT INSPECTION ".

   Is the inspection result normal? 

   YES: GO TO 8.

   NO: Replace "fuel level sensor unit and fuel pump". Refer to REMOVAL AND INSTALLATION .

8. CHECK INTERMITTENT INCIDENT

   Refer to "INTERMITTENT INCIDENT ".

   : INSPECTION END