NAVIGATION SYSTEM (for HDD) AVC-LAN Circuit

DESCRIPTION

Each unit of the navigation system connected to the AVC-LAN (communication bus) transfers the switch signals using the AVC-LAN.

If a short to +B or short to ground occurs in the AVC-LAN, the navigation system will not function normally because communication is not possible.

INSPECTION PROCEDURE

Note

The navigation computer sub-assembly is the master unit.

PROCEDURE


  1. INSPECT NAVIGATION COMPUTER SUB-ASSEMBLY


    1. A003ZVHE23

      Disconnect the H60 navigation computer sub-assembly connector.

    2. A003WO0E26

      Disconnect the H61 navigation computer sub-assembly connector.

    3. A003W6EE15

      Disconnect the H63 navigation computer sub-assembly connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      H60-13 (TX2+) - H60-14 (TX2-) Always 60 to 80 Ω
      H61-1 (TX1+) - H61-2 (TX1-) Always 60 to 80 Ω
      H61-12 (TX3+) - H61-13 (TX3-) Always 60 to 80 Ω
      H63-9 (TX+) - H63-10 (TX-) Always 60 to 80 Ω
      Text in Illustration
      *a

      Component without harness connected

      (Navigation Computer Sub-assembly)

    NG

    REPLACE NAVIGATION COMPUTER SUB-ASSEMBLY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (AVC-LAN CIRCUIT)

    Tech Tips

    For details of the connectors, refer to Terminals of ECU Click here.


    1. Referring to the AVC-LAN wiring diagram below, check all AVC-LAN circuits.


      1. Disconnect all connectors in all AVC-LAN circuits.

      2. Check for an open or short in all AVC-LAN circuits.

        A003YSUE01
        OK
        There is no open or short circuit.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT MALFUNCTIONING PARTS


    1. Disconnect and reconnect each slave unit one by one until the master unit returns to normal operation.

      Tech Tips


      • Check all slave units.

      • If disconnecting a slave unit causes the master unit to return to normal operation, the slave unit is defective and should be replaced.

      OK
      Master unit returns to normal operation.

    NG

    REPLACE NAVIGATION COMPUTER SUB-ASSEMBLY Click here

    OK

    REPLACE MALFUNCTIONING PARTS