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Home › Infiniti › 2008 › QX56 AWD › Repair and Diagnosis › Engine Performance › Engine Control Systems › Engine Control System - DTCS U1000 To P0308 › DTC P0132, P0152: A/F Sensor 1 › Diagnosis Procedure

Diagnosis 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 Body Ground Screw
      G05739402Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
    1. Disconnect A/F sensor 1 harness connector.
      Fig 2: Identifying A/F Sensor 1 Harness Connector
      G05739403Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Turn ignition switch ON.
    3. Check voltage between A/F sensor 1 terminal 4 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  4.

    NG: GO TO 3.

    Fig 3: Checking Voltage Between A/F Sensor 1 Terminal 4 And Ground
    G05739404Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E5, F14
    • IPDM E/R harness connector E119
    • 15A fuse
    • Harness for open or short between A/F sensor 1 and fuse

    Repair or replace harness or connectors.

  4. 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 A/F sensor 1 terminal and ECM terminal as follows.

      Refer to WIRING DIAGRAM .

      CONTINUITY REFERENCE CHART

        A/F sensor 1 terminal ECM terminal
      Bank 1 1 35
      2 56
      Bank 2 1 16
      2 75

      Continuity should exist. 

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

      Refer to WIRING DIAGRAM .

      CONTINUITY REFERENCE CHART

      Bank 1 Bank 2
      A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
      1 35 1 16
      2 56 2 75

      Continuity should not exist. 

    5. 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 INTERMITTENT INCIDENT

    Refer to "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

    OK or NG 

    OK: GO TO 6.

    NG: Repair or replace.

  6. REPLACE AIR FUEL RATIO (A/F) SENSOR 1

    Replace malfunctioning air fuel ratio (A/F) sensor 1.

    CAUTION:
    • Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
    • Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.

    INSPECTION END 

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