Code No. U1118: 4WD/Transfer ECU CAN timeout


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 ).
  • If diagnosis codes U1118 is set in ASTC-ECU, always diagnose the CAN bus line. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set. In this case, the set diagnosis code is not highly reliable.
  • 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 ).

OPERATION


The ASTC-ECU communicates with the transfer-ECU via the CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS


If the ASTC-ECU cannot receive any signal from the transfer-ECU for a predetermined period, this diagnosis code will be set.
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 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines

Q. Is diagnosis code No. U1118 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check whether a diagnosis code is set in the transfer-ECU (Refer to GROUP 23A - Troubleshooting <SS4II> ).

Q. Is the diagnosis code set?
Follow the relevant diagnosis code procedure. Then go to Step 5.
Go to Step 4.

STEP 4. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check whether an transfer-ECU "time-out" related diagnosis code is set in other ECUs.

Q. Is the diagnosis code set?
Replace the transfer-ECU (Refer to GROUP 23A - Transfer-ECU ). Then go to Step 5.
Go to Step 5.

STEP 5. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set.
(1)Erase the set diagnosis code.
(2)Ignition switch: "LOCK" (OFF)
(3)Ignition switch: "ON"

Q. Is diagnosis code No. U1118 set?
Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).