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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 P0138, P0158 Ho2S2 >> Diagnostic Procedure >> Procedure For Malfunction A

Procedure For Malfunction A

  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
      G04905369Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. 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)
    3. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.
      Fig 2: 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 3.

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

  3. 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
      P0138 74 1 1
      P0158 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
      P0138 74 1 1
      P0158 55 1 2

      Continuity should not exist. 

    3. Also check harness for 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 CONNECTOR FOR WATER 

    Check HO2S2 connectors for water.

    Water should not exist. 

    OK or NG 

    OK: GO TO 5.

    NG: Repair or replace 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