Multiplex Communication System Diagnosis System

Communication System. Lexus Is250, Is220D. Gse20 Ale20
Multiplex Communication. Lexus Is250, Is220D. Gse20 Ale20
  1. DESCRIPTION

  1. CHECK DLC3

  1. INSPECT BATTERY VOLTAGE

Multiplex Communication System -- Diagnosis System



DESCRIPTION
  1. The gateway ECU controls the functions of the multiplex communication system on the vehicle. Data of the multiplex communication system and the Diagnostic Trouble Codes (DTC) can be read through the Data Link Connector 3 (DLC3) of the vehicle.


CHECK DLC3


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System.Multiplex Communication System  Diagnosis System
  1. The vehicle uses ISO 9141-2 (Euro-OBD) as its communication protocol. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 9141-2 format.
    Verify the conditions listed in the table below:

    Symbols (Terminal No.)
    Terminal Description
    Condition
    Specified Condition
    SIL (7) - SG (5)
    Bus "+" line
    During transmission
    Pulse generation
    CG (4) - Body ground
    Chassis ground
    Always
    Below 1 Ω
    SG (5) - Body ground
    Signal ground
    Always
    Below 1 Ω
    BAT (16) - Body ground
    Battery positive
    Always
    11 to 14 V
    1. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.


  2. Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System.Multiplex Communication System  Diagnosis System
  3. Intelligent tester

    HINT:
    Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.
    1. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
    2. If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.

INSPECT BATTERY VOLTAGE
If the voltage is below 11 V, recharge or replace the battery before proceeding.
Standard voltage:
11 to 14 V