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Home >> Infiniti >> 2024 >> QX55 Essential >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can System (DTC/Circuit Diagnosis) >> Circuit Diagnosis >> Its Can Communication 1 Circuit >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK CAN DIAGNOSIS 

    Check the CAN diagnosis results from CONSULT to see that the ADAS CAN communication 1 circuit has no malfunction.

    Is the ADAS CAN communication 1 circuit normal?

    >>

    GO TO 2.

    >>

    Check and repair ADAS CAN communication 1 circuit.

  2. CONNECTOR INSPECTION 
    1. Turn the ignition switch OFF.
    2. Disconnect the battery cable from the negative terminal.
    3. Disconnect all the unit connectors on ITS CAN communication 1 circuit.
    4. Check terminals and connectors for damage, bend and loose connection.

    Is the inspection result normal?

    >>

    GO TO 3.

    >>

    Repair the terminal and connector.

  3. CHECK HARNESS CONTINUITY (OPEN CIRCUIT) 

    Check the continuity between the ADAS control unit harness connector and the distance sensor harness connector.

    ADAS control unit harness connector Distance sensor harness connector Continuity
    Connector No. Terminal No. Connector No. Terminal No.
    M258 6 E59 3 Existed
    7 6 Existed

    Is the inspection result normal?

    >>

    GO TO 4.

    >>

    Check the harness and repair the root cause.

  4. CHECK HARNESS CONTINUITY (SHORT CIRCUIT) 

    Check the continuity between the ADAS control unit harness connector terminals.

    ADAS control unit harness connector Continuity
    Connector No. Terminal No.
    M258 6 7 Not existed

    Is the inspection result normal?

    >>

    GO TO 5.

    >>

    Check the harness and repair the root cause.

  5. CHECK HARNESS CONTINUITY (SHORT CIRCUIT) 

    Check the continuity between the ADAS control unit harness connector and the ground.

    ADAS control unit harness connector Ground Continuity
    Connector No. Terminal No.
    M258 6 Not existed
    7 Not existed

    Is the inspection result normal?

    >>

    GO TO 6.

    >>

    Check the harness and repair the root cause.

  6. CHECK TERMINATION CIRCUIT 
    1. Remove the ADAS control unit and the distance sensor.
    2. Check the resistance between the ADAS control unit terminals.
      ADAS control unit Resistance (Ω)
      Terminal No.
      6 7 Approx. 108 - 132
    3. Check the resistance between the distance sensor terminals.
      Distance sensor Resistance (Ω)
      Terminal No.
      3 6 Approx. 108 - 132

    Is the measurement value within the specification?

    >>

    GO TO 7.

    >>

    Replace the ADAS control unit and/or the distance sensor.

  7. CHECK SYMPTOM 

    Connect all the connectors. Check if the symptoms described in the "Symptom (Results from interview with customer)" are reproduced.

    Inspection result

    Reproduced>>

    GO TO 8.

    >>

    Start the diagnosis again. Follow the trouble diagnosis procedure when past error is detected.

  8. CHECK UNIT REPRODUCTION 

    Perform the reproduction test as per the following procedure for each unit.

    1. Turn the ignition switch OFF.
    2. Disconnect the battery cable from the negative terminal.
    3. Disconnect one of the unit connectors of ITS CAN communication 1 circuit.
      NOTE: SYMBOL ADAS control unit and distance sensor have a termination circuit. Check other units first.
    4. Connect the battery cable to the negative terminal. Check if the symptoms described in the "Symptom (Results from interview with customer)" are reproduced.
      NOTE: SYMBOL Although unit-related error symptoms occur, do not confuse them with other symptoms.

    Inspection result

    Reproduced>>

    Connect the connector. Check other units as per the above procedure.

    >>

    Replace the unit whose connector was disconnected.

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