Inspection Procedure 19: You cannot enter the off-road mode when you operate the drive mode-selector. <4WD>


caution
  • If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - Troubleshooting ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the hydraulic unit assembly (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G sensor (Refer to ).

COMMENTS ON TROUBLE SYMPTOM


When you set the drive mode-selector to "4HLc" or "4LLc", the ASTC-ECU will enter the off-road mode, and "GRAVEL" will appear on the multi-information display in the combination meter.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnosis


Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

Go to Step 2.

Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ). Then go to Step 4.

STEP 2. M.U.T.-III diagnosis code


Use M.U.T.-III to check the diagnosis code for the ASTC system.

Q. Is the diagnosis code set?

Carry out the diagnosis for the diagnosis code (Refer to ).

Go to Step 3.

STEP 3. M.U.T.-III data list


Check the ASTC system data list.

Item No.
 Item name
 Normal condition
23
 Transfer SW position (SS4/ES4)
 Each time you operate the drive mode-selector, the drive mode is switched among "2H", "4H", "4HLc" and "4LLc".

Q. Is the check result normal?

Go to Step 4.

Diagnose the transfer-ECU (Refer to GROUP 23A - Troubleshooting <SS4II> ). Then go to Step 4.

STEP 4. Retest the system


When you set the drive mode-selector to "4HLc" or "4LLc", "GRAVEL" should appear on the multi-information display in the combination meter.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).