Fuel Level Sensor Signal Inspection

The following symptoms do not indicate a malfunction.

FUEL GAUGE 

• Depending on vehicle position or driving circumstance, the fuel in the tank flows and the pointer may fluctuate.
• If the vehicle is fueled with the ignition switch ON, the pointer will move slowly.

LOW-FUEL WARNING LAMP 

• Depending on vehicle position or driving circumstance, the fuel in the tank flows and the warning lamp ON timing may change.

1. Check Unified Meter And A/C Amp. Input Signal 
   1. Select METER A/C AMP on CONSULT-II.
   2. Using FUEL METER on DATA MONITOR , compare the value of DATA MONITOR with fuel gauge pointer of combination meter.
      Fig 1: Reading Fuel Meter Values On CONSULT-II In Data Monitor Mode

      Courtesy of NISSAN MOTOR CO., U.S.A.
      FUEL GAUGE POINTER RANGES
      
      

      Fuel Gauge Pointer	Reference Value Of Data Monitor [lit.]
      Full	Approx. 86
      Three quarters	Approx. 70
      Half	Approx. 48
      A quarter	Approx. 25
      Empty	Approx. 9

   OK or NG

   1. OK: GO TO 2.
   2. NG: Replace combination meter.

2. Check Fuel Level Sensor 

   Check components. Refer to CHECK FUEL LEVEL SENSOR UNIT  .

   OK or NG

   1. OK: GO TO 3.
   2. NG: Replace fuel level sensor unit.

3. Check Fuel Level Sensor (Sub) Circuit 
   1. Disconnect unified meter and A/C amp. connector and fuel level sensor unit (sub) connector.
   2. Check continuity between unified meter and A/C amp. harness connector M56 terminal 28 (W/B) and fuel level sensor unit (sub) harness connector B40 terminal 1 (LG).
      Fig 2: Verifying Continuity Unified Meter And A/C Amp. To Fuel Level Sensor Unit

      Courtesy of NISSAN MOTOR CO., U.S.A.

      Continuity should exist  .

   3. Check Continuity Between Unified Meter And A/C Amp. Harness Connector M56 Terminal 28 (W/B) And Ground.

      Continuity should not exist  .

   OK or NG

   1. OK: GO TO 4.
   2. NG: Repair harness or connector.

4. Check Fuel Level Sensor (Main. Sub) Circuit 
   1. Disconnect fuel level sensor unit and fuel pump (main) connector.
   2. Check continuity between fuel level sensor unit (sub) harness connector B40 terminal 2 (Y) and fuel level sensor unit and fuel pump (main) harness connector B39 terminal 2 (Y).
      Fig 3: Identifying Step 2 & 3 Testing Procedures

      Courtesy of NISSAN MOTOR CO., U.S.A.

      Continuity should exist  .

   3. Check continuity between fuel level sensor unit (sub) harness connector B40 terminal 2 (Y) and ground.

      Continuity should not exist  .

   OK or NG

   1. OK: GO TO 5.
   2. NG: Repair harness or connector.

5. Check Fuel Level Sensor (Main) Circuit 
   1. Check continuity between fuel level sensor unit and fuel pump (main) harness connector B39 terminal 5 (B) and unified meter and A/C amp. harness connector M56 terminal 36 (B/W).
      Fig 4: Testing Fuel Level Sensor Circuit

      Courtesy of NISSAN MOTOR CO., U.S.A.

      Continuity should exist  .

   2. Check continuity between fuel level sensor unit and fuel pump (main) harness connector B39 terminal 5 (B) and ground.

      Continuity should not exist  .

   OK or NG

   1. OK: GO TO 6.
   2. NG: Repair harness or connector.

6. Check Installation Condition 

   Check fuel level sensor unit installation, and check whether the float arm interferes or binds with any of the internal components in the fuel tank.

   OK or NG

   1. OK: Replace unified meter and A/C amp. Refer to REMOVAL AND INSTALLATION OF UNIFIED METER AND A/C AMP.  .
   2. NG: Install the fuel level sensor unit properly.