Diagnosis 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.
3. Turn ignition switch ON.
  
  Fig 1: Checking Fuel Pump Power Supply And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-III or tester.
  Voltage: Approximately 5V
OK or NG

OK: GO TO 3.

NG: GO TO 2.

Fig 2: Checking Voltage Between Fuel Level Sensor Unit And Fuel Pump Terminal 4 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors C1, E41
- Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
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 3 and ground. Refer to WIRING DIAGRAM .
  Continuity should exist.
3. Also check harness for short to power.
OK or NG

OK: GO TO 5.

NG: GO TO 4.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors C1, E41
- Harness for open or short between "fuel level sensor unit and fuel pump" and ground
Repair open circuit or short to power in harness or connector.
CHECK FUEL TANK TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 6.

NG: Replace "fuel level sensor unit and fuel pump".
CHECK INTERMITTENT INCIDENT
Refer to "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

INSPECTION END