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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 TPMS And HVAC 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 HARNESS CONTINUITY (OPEN CIRCUIT) 
    1. Turn the ignition switch OFF.
    2. Disconnect the battery cable from the negative terminal.
    3. Disconnect the following harness connectors.
      • ECM
      • Low tire pressure warning control unit
      • A/C auto amp.
    4. Check the continuity between the low tire pressure warning control unit harness connector and the A/C auto amp. harness connector.
      Low tire pressure warning control unit harness connector A/C auto amp. harness connector Continuity
      Connector No. Terminal No. Connector No. Terminal No.
      M43 2 M66 12 Existed
      1 11 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 low tire pressure warning control unit and the A/C auto amp.

      NO: Replace the PCB harness.