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Home › Nissan-Datsun › 2008 › Quest Base › Repair and Diagnosis › Engine Performance › Engine Control Systems › Engine Control System - DTCS P0137 Through P0443 › DTC P0137, P0157 Ho2S2 › Diagnostic Procedure

Diagnostic Procedure

  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: Identifying Ground Screws On Body
      G04905352Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CLEAR THE SELF-LEARNING DATA 

    With CONSULT-III 

    1. Start engine and warm it up to normal operating temperature.
    2. Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-III.
    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 P0171 or P0174 detected? 

      Is it difficult to start engine? 

    Without CONSULT-III 

    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 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 P0171 or P0174 detected? 

      Is it difficult to start engine? 

      Fig 2: Identifying Mass Air Flow Sensor With Air Cleaner
      G04905244Courtesy of NISSAN MOTOR CO., U.S.A.

    Yes or No 

    Yes: Perform trouble diagnosis for DTC P0171, P0174. Refer to DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION .

    No: GO TO 3.

  3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect heated oxygen sensor 2 harness connector.
      • Oil pan (1)
      • Heated oxygen sensor 2 (bank 2) harness connector (2)
      • Heated oxygen sensor 2 (bank 1) harness connector (3)
    4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    5. Also check harness for short to ground and short to power.
      Fig 3: Identifying Heated Oxygen Sensor 2 (Bank 2 And 1) Harness Connector With Oil Pan Connector
      G04905224Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 4.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.

      Refer to WIRING DIAGRAM .

      CONNECTOR TERMINAL CONTINUITY SPECIFICATION

      DTC Terminals Bank
      ECM Sensor
      P0137 74 1 1
      P0157 55 1 2

      Continuity should exist. 

    2. Check harness continuity between the following terminals and ground.

      Refer to WIRING DIAGRAM .

      CONNECTOR TERMINAL CONTINUITY SPECIFICATION

      DTC Terminals Bank
      ECM Sensor
      P0137 74 1 1
      P0157 55 1 2

      Continuity should not exist. 

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO 5.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  5. CHECK HEATED OXYGEN SENSOR 2 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 6.

    NG: Replace malfunctioning heated oxygen sensor 2.

  6. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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