Diagnosis System

UF1AE TRANSFER: FOUR WHEEL DRIVE CONTROL SYSTEM: DIAGNOSIS SYSTEM

DIAGNOSIS SYSTEM

1. DIAGNOSIS SYSTEM





(a) Inspect the battery voltage.
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge the battery before proceeding.

(b) 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.





HINT:
If the display shows a communication error message when the cable of the Techstream is connected to the DLC3, the engine switch is turned on (IG) and the Techstream 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





(a) 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.

3. CHECK 4WD INDICATOR LIGHT





(a) Using SST, connect terminals TC and CG of the DLC3 (to enter the DTC output mode).
SST: 09843-18040

(b) Turn the engine switch on (IG).
(c) "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.




- If the 4WD control system is not normal, "DIAG 4WD XX(DTC)" will be displayed on the multi-information display.




- 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" TC and CG Terminal Circuit.
- If the 4WD indicator light check result is not normal, proceed to troubleshooting for the 4WD indicator light circuit.






4. FAIL-SAFE FUNCTION
(a) 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.