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Diagnosis System

WARNING: This page is about a different variant/trim than selected.
  1. DIAGNOSIS SYSTEM 
    1. Inspect the battery voltage.

      Standard voltage: 11 to 14 V 

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

      Fig 1: Identifying DLC3 Connector Terminals
      G05318636Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the DLC3.

      The 4WD 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.

      Verify the conditions listed in the table below.

      CONNECTOR TERMINAL REFERENCE

      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
      CANH (6) - CANL (14) HIGH-level CAN bus line Engine switch off 54 to 67 Ω
      CANH (6) - Battery positive HIGH-level CAN bus line Engine switch off 1 MΩ or higher
      CANH (6) - CG (4) HIGH-level CAN bus line Engine switch off 3 kΩ or higher
      CANL (14) - Battery positive LOW-level CAN bus line Engine switch off 1 MΩ or higher
      CANL (14) - CG(4) LOW-level CAN bus line Engine switch off 3 kΩ or higher

      HINT:

      If the display shows a communication error message when the cable of the intelligent tester is connected to the DLC3, the engine switch is turned on (IG) and the intelligent tester is operated, there is a problem on either the vehicle side or the tester 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 tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's operator's manual.
  2. FUNCTION OF 4WD INDICATOR 
    1. The 4WD indicator light in the combination meter assembly (multi-information display) warns the driver of abnormal or poor condition of the four wheel drive control system.
      Fig 2: Multi-Information Display - Check 4WD
      G05318637Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. CHECK 4WD INDICATOR LIGHT 
    1. Using SST, connect terminals TC and CG of the DLC3 (to enter the DTC output mode).

      SST 09843-18040 

    2. Turn the engine switch on (IG).
      Fig 3: Identifying Terminals TC And CG Of DLC3
      G05318638Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. "DIAG" is displayed on the multi-information display, and the 4WD control ECU checks the system for malfunctions.
      • If the 4WD control system is normal, "DIAG 4WD OK" will be displayed on the multi-information display.
        Fig 4: Display 4WD OK On Multi-Information Display
        G05295807Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      • If the 4WD control system is not normal, "DIAG 4WD XX (DTC)11 will be displayed on the multi-information display.
        Fig 5: Display DIAG 4WD XX (DTC) On Multi-Information Display
        G05295808Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      • Although the Test Mode is not set for the 4WD control system, the message shown in the illustration will be displayed on the multi-information display when the Test Mode is activated to check the VSC, etc.

      HINT:

      • Test Mode DTCs will not be stored because the Test Mode is not set.
      • On the multi-information display, VSC, TIRE PRESSURE and 4WD are displayed in order.
      • If the systems above are not displayed on the multi-information display, there may be a malfunction in "TC AND CG TERMINAL CIRCUIT " .
      • If the 4WD indicator light check result is not normal, proceed to troubleshooting for the 4WD indicator light circuit.
        Fig 6: Display 4WD TEST MODE On Multi-Information Display
        G05318641Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TROUBLESHOOTING CHART

      Trouble Area See
      4WD indicator light (Remains on) PROBLEM SYMPTOMS TABLE 
      4WD indicator light (Does not come on)
  4. FAIL-SAFE FUNCTION 
    1. If following malfunctions occur, the 4WD control ECU will stop the function of 4WD control system or partly change the function to control the system.
      FAIL-SAFE FUNCTION

      Malfunction Control
      Malfunction in a speed sensor Stop the function
      Malfunction in the steering angle sensor and throttle signal line Partly change the function