Diagnostic Procedure

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten engine two screws on the body.
  Refer to "GROUND INSPECTION ".
  
  Fig 1: Checking ECM Ground Connections
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 2.
2. NG : Repair or replace ground connections.
CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect "fuel level sensor unit and fuel pump" harness connector.
  
  Fig 2: Disconnecting Fuel Level Sensor Unit And Fuel Pump Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Turn ignition switch ON.
4. Check voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-II or tester.
  1. Voltage: Approximately 5V
  Fig 3: Checking Voltage Between Fuel Level Sensor Unit Connector Terminal And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK : GO TO 4.
2. NG : GO TO 3.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M59, F27
- Harness connectors B3, M16
- Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
  1. : Repair open circuit or short to ground or short to power in 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 ground.
  Refer to WIRING DIAGRAM .
  1. Continuity should exist.
3. Also check harness for short to power.
OK or NG
1. OK : GO TO 5.
2. NG : Repair open circuit or short to power in harness or connectors.
CHECK FUEL TANK TEMPERATURE SENSOR
Refer to, "COMPONENT INSPECTION ".

OK or NG
1. OK : GO TO 6.
2. NG : Replace fuel level sensor unit.
CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
1. : INSPECTION END