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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> External Pages >> Different car >> Section 1057 (Engine Control System) >> DTC P1278, P1288: A/F Sensor 1 >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground three screws on the body. Refer to GROUND INSPECTION  .
      Fig 1: Loosening And Retightening Ground Three Screws On Body
      G00775803Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace ground connections.
  2. RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1. 

    Loosen and retighten the air fuel ratio (A/F) sensor 1.

    Fig 2: Loosening And Retightening Air Fuel Ratio (A/F) Sensor
    G00775804Courtesy of NISSAN MOTOR CO., U.S.A.
    1. Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb) 
      1. GO TO 3.
  3. CHECK EXHAUST GAS LEAK 
    1. Start engine and run it at idle.
    2. Listen for an exhaust gas leak before three way catalyst (manifold).
      Fig 3: Checking Exhaust Gas Leak
      G00775805Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Repair or replace.
  4. CHECK FOR INTAKE AIR LEAK 

    Listen for an intake air leak after the mass air flow sensor.

    OK or NG 

    1. OK: GO TO 5.
    2. NG: Repair or replace.
  5. CLEAR THE SELF-LEARNING DATA 

    With CONSULT-II 

    1. Start engine and warm it up to normal operating temperature.
    2. Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-II.
    3. Clear the self-learning control coefficient by touching "CLEAR" or "START".
    4. Run engine for at least 10 minutes at idle speed.

      Is the 1st trip DTC P0171, P172, P0174 or P0175 detected? 

      Is it difficult to start engine? 

      Fig 4: Identifying WORK SUPPORT Screen
      G00775806Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Start engine and warm it up to normal operating temperature.
    2. Turn ignition switch OFF.
    3. Disconnect mass air flow sensor harness connector.
      Fig 5: Disconnecting Mass Air Flow Sensor Harness Connector
      G00775807Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Restart engine and let it idle for at least 3 seconds.
    5. Stop engine and reconnect mass air flow sensor harness connector.
    6. Make sure DTC P0102 is displayed.
    7. Erase the DTC memory. Refer to HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION  .
    8. Make sure DTC P0000 is displayed.
    9. Run engine for at least 10 minutes at idle speed.

      Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? 

      Is it difficult to start engine? 

    Yes or No 

    1. Yes: Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION  , DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION  .
    2. No: GO TO 6.
  6. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
      Fig 6: Disconnecting Air Fuel Ratio Sensor 1 Harness Connector
      G00775808Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-II or tester.
      Fig 7: Checking Voltage Between A/F Sensor 1 Terminal 3 And Ground
      G00775809Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Voltage: Battery voltage 

    OK or NG 

    1. OK: GO TO  8 .
    2. NG: GO TO 7.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E5, F14
    • IPDM E/R harness connector E122
    • 15A fuse
    • Harness for open or short between A/F sensor 1 and fuse
      1. Repair or replace harness or connectors.
  8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between the following terminals.

      Refer to WIRING DIAGRAM  .

      Fig 8: Checking Harness Continuity Between Terminals
      G00775810Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Continuity should exist. 
    4. Check harness continuity between the following terminals and ground.

      Refer to WIRING DIAGRAM  .

      Fig 9: Checking Harness Continuity Between Terminals And Ground
      G00775811Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Continuity should not exist. 
    5. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO 9.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  9. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER 

    Refer to COMPONENT INSPECTION  .

    OK or NG 

    1. OK: GO TO 10.
    2. NG: Replace A/F sensor 1.
  10. CHECK MASS AIR FLOW SENSOR 

    Refer to COMPONENT INSPECTION  .

    OK or NG 

    1. OK: GO TO 11.
    2. NG: Replace mass air flow sensor.
  11. CHECK PCV VALVE 

    Refer to POSITIVE CRANKCASE VENTILATIONS  .

    OK or NG 

    1. OK: GO TO 12.
    2. NG: Repair or replace PCV valve.
  12. CHECK INTERMITTENT INCIDENT 

    Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

    OK or NG 

    1. OK: Replace A/F sensor 1.
    2. NG: Repair or replace.
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