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Home >> Nissan-Datsun >> 2002 >> Sentra SE-R, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 1437 (Engine Control System) >> DTC P0139, P0159: Ho2S2 >> 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
      G02401477Courtesy 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-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 P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine? 

      Fig 2: Scan Tool Display "Work Support"
      G02401478Courtesy 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, and restart and run engine for at least 5 seconds at idle speed.
    4. Stop engine and reconnect mass air flow sensor harness connector.
    5. Make sure DTC P0102 is displayed.
    6. Erase the DTC memory. Refer to "HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION ".
    7. Make sure DTC P0000 is displayed.
    8. 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

    Fig 3: Disconnecting Mass Air Flow Sensor Harness Connector
    G02401479Courtesy of NISSAN MOTOR CO., U.S.A.
  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.
      Fig 4: Disconnecting Heated Oxygen Sensor 2 Harness Connector
      G02401480Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check harness continuity between HO2S2 terminal 4 and ECM terminal 78. Refer to WIRING DIAGRAM .
      • Continuity should exist. 
    5. Also check harness for short to ground and short to power.

    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 .
      Fig 5: DTC Terminals & Bank Reference Chart
      G02401481Courtesy of NISSAN MOTOR CO., U.S.A.
      • Continuity should exist. 
    2. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
      Fig 6: DTC Terminals & Bank Reference Chart
      G02401482Courtesy of NISSAN MOTOR CO., U.S.A.
      • Continuity should not exist. 
    3. Also check harness for short to power short to ground.

    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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