Lexus IS250 · Service Manual BODY ELECTRICAL

AVC-LAN Circuit

Circuit diagnosis

DESCRIPTION

Each unit of the audio system connected to the AVC-LAN (communication bus) transfers the signal of each switch by communication.
When a short to +B or short to ground occurs in this AVC-LAN, the audio system will not function normally as the communication is discontinued.

INSPECTION PROCEDURE


1. INSPECT RADIO RECEIVER
E121249E01
  1. Disconnect the radio receiver connectors.

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

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    ATX+ - ATX-
    Always
    60 to 80 Ω
    TXM+ - TXM-
    Always
    60 to 80 Ω
    TX+ - TX-
    Always
    60 to 80 Ω



NG
REPLACE RADIO RECEIVER
OK


2. CHECK HARNESS AND CONNECTOR

HINT:
For details of the connectors, refer to the "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.

      OK:
      There is no open or short circuit.

      E121250E01



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE


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