Diagnostic Procedure

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel level sensor unit and fuel pump harness connector. Figure .
3. Turn ignition switch ON.
4. Check voltage between fuel level sensor unit terminal 4 and ground with CONSULT-II or tester.
  
  Fig 1: Checking Fuel Tank Temperature Sensor Power Supply Circuit
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  OK or NG
1. OK: GO TO 3 .
2. NG: GO TO 2.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B3, M6
- Harness connectors M81, F49
- Harness for open or short between ECM and fuel level sensor unit and fuel pump
1. : Repair harness or connector.
CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between fuel level sensor unit and fuel pump terminal 5 and body ground. Refer to Wiring Diagram.
  Continuity should exist.
3. Also check harness for short to power.
  OK or NG
1. OK: GO TO 4.
2. NG: Repair open circuit or short to power in harness or connectors.
CHECK FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between fuel level sensor unit and fuel pump terminals 4 and 5 by heating with hot water or heat gun as shown in Figure .
  OK or NG
1. OK: GO TO 5.
2. NG: Replace fuel level sensor unit.
CHECK INTERMITTENT INCIDENT
Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .
1. : INSPECTION END