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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> External Pages >> Different car >> Section 1430 (Engine Control System) >> DTC P1274, P1284: A/F Sensor 1 >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Nissan 350Z. 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 three ground screws on the body. Refer to "GROUND INSPECTION ".
      Fig 1: Loosen & Retighten Three Ground Screws On The Body
      G02401955Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO 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: Loosen & Retighten The Air Fuel Ratio (A/F) Sensor 1
    G02401956Courtesy of NISSAN MOTOR CO., U.S.A.
    • Tightening torque: 50 N.m (5.1 kg.m, 37 ft.lb) 
    • : GO TO 3.
  3. 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".
    4. Run engine for at least 10 minutes at idle speed.

      Is the 1st trip DTC P0172 or P0175 detected? 

      Is it difficult to start engine? 

      Fig 3: Scan Tool Display "Work Support"
      G02401957Courtesy 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.
    4. Restart engine and let it idle for at least 5 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 P0172 or P0175 detected? 

      Is it difficult to start engine? 

      Fig 4: Mass Air Flow Sensor
      G02401958Courtesy of NISSAN MOTOR CO., U.S.A.

    Yes or No

  4. CHECK HARNESS CONNECTOR 
    1. Turn ignition switch OFF.
    2. Disconnect A/F sensor 1 harness connector.
      Fig 5: Disconnecting A/F Sensor 1 Harness Connector
      G02401959Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check harness connector for water.

      Water should not exit. 

    OK or NG

    • OK: GO TO 5.
    • NG: Repair or replace harness connector.
  5. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Turn ignition switch ON.
    2. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-II or tester.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  7.
    • NG: GO TO 6.
    Fig 6: A/F Sensor 1 Terminal 3 & Ground Voltage Test
    G02401960Courtesy of NISSAN MOTOR CO., U.S.A.
  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M15, E108
    • Harness connectors E12, F3
    • Fuse block (J/B) connector M4
    • 15A fuse
    • Harness for open or short between A/F sensor 1 and fuse
      • : Repair or replace harness or connectors.
  7. 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 7: A/F Sensor Terminal & ECM Terminal Specification Table
      G02401961Courtesy of NISSAN MOTOR CO., U.S.A.
      • Continuity should exist. 
    4. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
      Fig 8: A/F Sensor Terminal & ECM Terminal BANK 1 & 2 Specification Table
      G02401962Courtesy of NISSAN MOTOR CO., U.S.A.
      • Continuity should not exist. 
    5. Also check harness for short to power and short to ground.

    OK or NG

    • OK: GO TO 8.
    • NG: Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK A/F SENSOR 1 HEATER 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 9.
    • NG: Replace A/F sensor 1.
  9. CHECK INTERMITTENT INCIDENT 

    Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG

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