LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2015 >> Q60 Base, 2D Coupe >> Repair and Diagnosis >> Steering >> Steering Control Systems >> Steering Control System (Coupe) >> DTC/Circuit Diagnosis >> Vehicle Speed Signal Circuit >> Diagnosis Procedure >> Diagnostic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Test

  1. PERFORM UNIFIED METER AND A/C AMP. SELF-DIAGNOSIS

    With CONSULT 

    Perform unified meter and A/C amp. self-diagnosis.

    Is any error system detected?

    YES 

    Check the error system.

    NO 

    GO TO STEP 2. 

  2. CHECK HARNESS BETWEEN UNIFIED METER AND A/C AMP. AND POWER STEERING CONTROL UNIT

    1. Turn the ignition switch OFF.
    2. Disconnect unified meter and A/C amp. harness connector.
    3. Disconnect power steering control unit harness connector.
    4. Check the continuity between unified meter and A/C amp. harness connector and power steering control unit harness connector.
      Unified meter and A/C amp. Power steering control unit Continuity
      Connector Terminal Connector Terminal
      M66 8 M108 8 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 VEHICLE SPEED SIGNAL (1)

    1. Turn the ignition switch OFF.
    2. Connect unified meter and A/C amp. harness connector.
    3. Check the unified meter and A/C amp. input/output standard values. Refer to REFERENCE VALUE .

    Is the inspection result normal?

    YES 

    GO TO STEP 4. 

    NO 

    Replace unified meter and A/C amp. Refer to EXPLODED VIEW .

  4. CHECK VEHICLE 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 8 - Ground Vehicle speed:
      40 km/h (25 MPH)
      CAUTION:

      Check the air pressure of tire under standard condition.

      GNSSEIA0775E-775Courtesy 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 the unified meter and A/C amp. pin terminals for damage or loose connection with harness connector.

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    Repair or replace damaged parts.