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Home >> Infiniti >> 2009 >> EX35 Base, AWD >> Repair and Diagnosis >> Steering >> Steering Control Systems >> Power Steering Control System >> Component Diagnosis >> Engine Speed Signal Circuit >> Diagnosis Procedure
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Diagnosis Procedure

  1. PERFORM ECM SELF-DIAGNOSIS

    With CONSULT-III 

    1. Turn the ignition switch ON.

      Perform ECM self-diagnosis. Refer to "Consult-III Function ".

      Is any DTC detected? 

      YES: Check the DTC.

      NO: GO TO 2.

  2. CHECK HARNESS BETWEEN ECM AND POWER STEERING CONTROL UNIT
    1. Turn the ignition switch OFF.
    2. Disconnect ECM harness connectors.
    3. Disconnect power steering control unit harness connector.
    4. Check continuity between ECM harness connector and power steering control unit harness connector.
      POWER STEERING CONTROL UNIT CONTINUITY CHART

      ECM Power steering control unit Continuity
      Connector Terminal Connector Terminal
      M107 110 M108 10 Existed
    5. Check continuity between power steering control unit harness connector and ground.
      POWER STEERING CONTROL UNIT CONTINUITY CHART

      Power steering control unit - Continuity
      Connector Terminal
      M108 10 Ground Not existed

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Repair or replace damaged parts.

  3. CHECK ENGINE SPEED SIGNAL (1)
    1. Connect ECM harness connectors.
    2. Check signal between ECM harness connector and ground with oscilloscope.
      ECM VOLTAGE CHART

      ECM - Condition Voltage (Approx.)
      Terminal
      110 Ground Engine is running
      • Warm-up condition
      • Idle speed
      G04886641Courtesy of NISSAN MOTOR CO., U.S.A.
      Engine is running
      • Warm-up condition
      • Engine speed: Approx. 2,000 RPM
      G04886642Courtesy of NISSAN MOTOR CO., U.S.A.

      Is the inspection result normal? 

      YES: GO TO 4.

      NO: Replace ECM. Refer to "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Description ".

  4. CHECK ENGINE SPEED SIGNAL (2)
    1. Turn the ignition switch OFF.
    2. Connect power steering control unit harness connector.
    3. Check signal between power steering control unit harness connector and ground with oscilloscope.
      POWER STEERING CONTROL UNIT VOLTAGE CHART

      Power steering control unit - Condition Voltage (Approx.)
      Connector Terminal
      M108 10 Ground Engine is running
      • Warm-up condition
      • Idle speed
      G04886641Courtesy of NISSAN MOTOR CO., U.S.A.
      Engine is running
      • Warm-up condition
      • Engine speed: Approx. 2,000 RPM
      G04886642Courtesy of NISSAN MOTOR CO., U.S.A.

      Is the inspection result normal? 

      YES: GO TO 5.

      NO: Replace power steering control unit. Refer to "EXPLODED VIEW ".

  5. CHECK TERMINALS AND HARNESS CONNECTORS
    • Check power steering control unit pin terminals for damage or loose connection with harness connector.
    • Check ECM pin terminals for damage or loose connection with harness connector.

      Is the inspection result normal? 

      YES: INSPECTION END

      NO: Repair or replace damaged parts.

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