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Home >> Infiniti >> 2015 >> Q60 Base, 2D Coupe >> Repair and Diagnosis >> Steering >> Steering Control Systems >> Steering Control System (Coupe) >> DTC/Circuit Diagnosis >> Engine Speed Signal Circuit >> Diagnosis Procedure >> Diagnostic Test
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Diagnostic Test

  1. PERFORM ECM SELF-DIAGNOSIS

    With CONSULT 

    Perform ECM self-diagnosis. Refer to DTC INDEX .

    Is any error system detected?

    YES 

    Check the error system.

    NO 

    GO TO STEP 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 the continuity between ECM harness connector and power steering control unit harness connector.
      ECM Power steering control unit Continuity
      Connector Terminal Connector Terminal
      M107 110 M108 10 Existed

      Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES 

    GO TO STEP 3. 

    NO 

    Repair or replace damaged parts.

  3. CHECK ENGINE SPEED SIGNAL (1)

    1. Turn the ignition switch OFF.
    2. Connect ECM harness connectors.
    3. Check the signal between ECM harness connector and ground with oscilloscope.
      ECM Value (Approx.)
      Connector Terminal Condition
      M107 110 - Ground Engine speed: At idle
      (Warm-up condition)
      GNSPBIA3654J-654Courtesy of NISSAN NORTH AMERICA, INC.
      Engine speed: Approx. 2, 000 rpm
      (Warm-up condition)
      GNSPBIA3655J-655Courtesy of NISSAN NORTH AMERICA, INC.

      Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES 

    GO TO STEP 4. 

    NO 

    Replace ECM. Refer to DESCRIPTION .

  4. CHECK ENGINE SPEED SIGNAL (2)

    1. Turn the ignition switch OFF.
    2. Connect power steering control unit harness connector.
    3. Check the signal between power steering control unit harness connector and ground with oscilloscope.
      Power steering control unit Value (Approx.)
      Connector Terminal Condition
      M108 10 - Ground Engine speed: At idle
      (Warm-up condition)
      GNSPBIA3654J-654Courtesy of NISSAN NORTH AMERICA, INC.
      Engine speed: Approx. 2, 000 rpm
      (Warm-up condition)
      GNSPBIA3655J-655Courtesy of NISSAN NORTH AMERICA, INC.

      Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES 

    GO TO STEP 5. 

    NO 

    Replace power steering control unit. Refer to EXPLODED VIEW .

  5. CHECK TERMINALS AND HARNESS CONNECTORS

    • Check the 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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