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Home >> Infiniti >> 2013 >> QX56 AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (LAN System (Can)) >> DTC/Circuit Diagnosis >> Main Line Between DLC And ADP Circuit >> Diagnosis Procedure
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Diagnosis Procedure

WARNING: This page is about a different car, the 2013 Infiniti M56 and 2013 Infiniti M37. However, it is still accessible from the selected car via links, so may be relevant.
  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 (connector side and harness side).
      • Harness connector M20 and PCB harness side connector
      • Harness connector M7
      • Harness connector B1

      Is the inspection result normal? 

      YES: GO TO 2.

      NO: Repair the terminal and connector.

  2. CHECK HARNESS CONTINUITY (OPEN CIRCUIT) 
    1. Disconnect the harness connector M20.
    2. Check the continuity between the data link connector and the PCB harness connector.
      Data link connector PCB harness connector Continuity
      Connector No. Terminal No. Terminal No.
      M182 13 24 Existed
      12 27 Existed

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Replace the PCB harness.

    3. CHECK HARNESS CONTINUITY (OPEN CIRCUIT) 
      1. Disconnect the harness connectors M7 and B1.
      2. Check the continuity between the harness connectors.
        Harness connector Harness connector Continuity
        Connector No. Terminal No. Connector No. Terminal No.
        M20 24 M7 34 Existed
        27 35 Existed

        Is the inspection result normal? 

        YES: GO TO 4.

        NO: Repair the main line between the harness connectors M20 and M7.

    4. CHECK HARNESS CONTINUITY (OPEN CIRCUIT) 

      Check the continuity between the harness connector terminals.

      Connector No. Terminal No. Continuity
      B1 34 32 Existed
      35 33 Existed

      Is the inspection result normal? 

      YES (Present error): Check CAN system type decision again.

      YES (Past error): Error was detected in the main line between the data link connector and the driver seat control unit.

      NO: Replace the body harness.