FixVault

Diagnosis System

  1. DESCRIPTION 

    The network gateway ECU controls the functions of the multiplex communication system on the vehicle. Data of the multiplex communication system and the Codes (DTC) can be read in the Connector DLC3 of the vehicle.

  2. CHECK DLC3 

    The vehicle uses ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

    Fig 1: Checking DLC3
    G02957495Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    DLC3

    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 ohms
    SG (5) - Body ground Signal ground Always Below 1 ohms
    BAT (16) - Body ground Battery positive Always 11 to 14 V

    HINT:

    Connect the cable of the hand-held tester to the DLC3, turn the power switch ON (IG) and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or the tester. If communication is normal when the hand-held tester is connected to another vehicle, inspect the DLC3 on the original vehicle.

    If communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.

    Fig 2: Connecting Cable Of Hand-Held Tester To DLC3
    G02957496Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT BATTERY VOLTAGE 

    Standard: 11 to 14 V 

    If the voltage is below 11 V, recharge or replace the battery before proceeding.