Diagnosis System

1. Inspect the battery voltage.

   Voltage: 

   11 to 14 V 

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

   Fig 1: Identifying DLC3 Connector Terminals

   Courtesy 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.

   DLC3 CONNECTOR TERMINALS 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.

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Turn the engine switch on (IG), and check that the master caution indicator comes on for approximately 3 seconds.

   HINT:

   The master caution indicator goes off while the system is in the DTC output mode and blinks while other systems are in the Test Mode.

   Fig 3: Identifying Master Warning Light

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Using SST, connect terminals TC and CG of the DLC3 (to be in the DTC output mode).

   SST 09843-18040 

2. Turn the engine switch on (IG).
   Fig 4: Identifying DLC3 Connector Terminals

   Courtesy 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 5: Multi Information Display (1 Of 3)

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • If the 4WD control system is not normal, "DIAG 4WD XX(DTC)" will be displayed on the multi-information display.
     Fig 6: Multi Information Display (2 Of 3)

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   • Although the Test Mode is not set for the 4WD control system, a message on the left will be displayed on the multi-information display when the Test Mode is activated for checking the VSC, etc.
     Fig 7: Multi Information Display (3 Of 3)

     Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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" (See 4WD INDICATOR LIGHT DOES NOT COME ON  ).
   • If the 4WD indicator light check result is not normal, proceed to troubleshooting for the 4WD indicator light circuit.
     TROUBLE AREA - PROCEDURE
     
     

     Trouble Area	See procedure
     4WD indicator light (Remains on)	4WD INDICATOR LIGHT REMAINS ON
     4WD indicator light (Does not come on)	4WD INDICATOR LIGHT DOES NOT COME ON

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.
   MALFUNCTION - CONTROL
   
   

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