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

Diagnosis Procedure

  1. CHECK CONNECTOR 
    1. Turn the ignition switch OFF.
    2. Disconnect the battery cable from the negative terminal.
    3. Check the following terminals and connectors for damage, bend and loose connection (unit side and connector side).
      • Chassis control module
      • 6CH CAN gateway

    Is the inspection result normal?

    >>

    GO TO 2.

    >>

    Repair the terminal and connector.

  2. CHECK HARNESS CONTINUITY (OPEN CIRCUIT) 
    1. Disconnect the connector of 6CH CAN gateway.
    2. Check the continuity between the 6CH CAN gateway harness connector terminals.
      6CH CAN gateway harness connector Continuity
      Connector No. Terminal No.
      M462 6 9 Existed
      18 21 Existed

    Is the inspection result normal?

    >>

    GO TO 3.

    >>

    Check the harness and repair the root cause (Chassis CAN communication 1 circuit side).

  3. CHECK HARNESS FOR OPEN CIRCUIT 
    1. Connect the connector of 6CH CAN gateway.
    2. Disconnect the connector of chassis control module.
    3. Check the resistance between the chassis control module harness connector terminals.
      Chassis control module harness connector Resistance (Ω)
      Connector No. Terminal No.
      M96 4 3 Approx. 54 - 66

    Is the measurement value within the specification?

    >>

    GO TO 4.

    >>

    Repair the chassis control module branch line.

  4. CHECK POWER SUPPLY AND GROUND CIRCUIT 

    Check the power supply and the ground circuit of the chassis control module. Refer to Diagnosis Procedure .

    Is the inspection result normal?

    >>

    Replace the chassis control module. Refer to Removal and Installation .

    >>

    Error was detected in the chassis control module branch line.

    >>

    Repair the power supply and the ground circuit.