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Diagnosis System

  1. CHECK DLC3 
    1. The seat belt control ECU uses CAN and the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
    Fig 1: Checking DLC3
    G03002635Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    DLC3

    Symbols (Terminals 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 14V
    CANH (6) - CANL HIGH-level CAN bus line IG switch OFF 54 to 67 Ω
    CANH (6) - Battery positive HIGH-level CAN bus line IG switch OFF 1 MΩ or Higher
    CANH (6) - CG (4) HIGH-level CAN bus line IG switch OFF 3 kΩ or Higher
    CANL (14) - Battery positive LOW-level CAN bus line IG switch OFF 1 MΩ or Higher
    CANL (14) -CG (4) LOW-level CAN bus line IG switch OFF 3 kΩ or Higher

    HINT:

    If the display shows UNABLE TO CONNECT TO VEHICLE when you connect the cable of the hand-held tester to the DLC3, turn the ignition switch to the ON position and operate the hand-held tester, there is a problem on the vehicle side or tool side.

    • If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
    • If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the tool's instruction manual.
  2. FUNCTION OF WARNING LIGHT AND MESSAGE 
    1. The master warning light and warning message of the multi-information display in the combination meter warns the driver of the abnormal or poor conditions of the pre-collision safety system.
      Fig 2: Identifying Master Warning Light And Multi-Information Display
      G03002636Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Initial check.
      1. After turning the ignition switch to the LOCK position, wait more than 2 seconds and then turn the ignition switch to the ON position. Perform pre-collision safety system diagnosis for approximately 3 seconds after turning the ignition switch to the ON position.
      2. If a malfunction is detected during the initial check, "Check PCS system" or "PCS not Available Now" is displayed on the multi-information display in the combination meter assy during the initial check (approximately 3 seconds after turning the ignition switch to the ON position.
    3. Constant check.
      1. The seat belt control ECU and cruise control ECU assy (distance control ECU) constantly monitor the pre-collision safety system for malfunctions after the initial check period (approximately 3 seconds after turning the ignition switch to the ON position).
      2. "Check PCS system" or "PCS not Available Now" is displayed on the multi-information display in the combination meter assy when the constant check detects malfunctions in the pre-collision safety system.
    4. Review.
      MASTER WARNING LIGHT - REFERENCE TABLE

      Master Warning Warning Message Detail DTC
      Illuminate Check PCS system This message appears when the seat belt control ECU detects a system malfunction. O
      Illuminate PCS not Available Now This message appears when the seat belt control ECU is in the fail-safe mode (see FAIL-SAFE CHART  ). -
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