NAVIGATION SYSTEM AVC-LAN Circuit

DESCRIPTION

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

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

WIRING DIAGRAM

A0048A6E01
*a Navigation ECU
*b Radio and Display Receiver Assembly

CAUTION / NOTICE / HINT

Tech Tips

The radio and display receiver assembly is the master unit.

PROCEDURE


  1. INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY


    1. A004BEHE02
      Text in Illustration
      *a

      Component without harness connected

      (Radio and Display Receiver Assembly)

      Disconnect the radio and display receiver assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z9-9 (TX+) - z9-10 (TX-) Always 60 to 80 Ω

    NG

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - NAVIGATION ECU)


    1. Disconnect the z9 radio and display receiver assembly connector.

    2. Disconnect the z8 navigation ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z9-9 (TX+) - z8-2 (TX+) Always Below 1 Ω
      z9-10 (TX-) - z8-3 (TX-) Always Below 1 Ω
      z9-9 (TX+) - Body ground Always 10 kΩ or higher
      z9-10 (TX-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT NAVIGATION ECU


    1. Disconnect and reconnect the navigation ECU until the radio and display receiver assembly returns to normal operation.

      OK
      Radio and display receiver assembly returns to normal operation.

      Tech Tips

      If disconnecting a navigation ECU causes the radio and display receiver assembly to return to normal operation, the navigation ECU is defective and should be replaced.


    OK

    REPLACE NAVIGATION ECU Click here

    NG

    REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY Click here