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 - CAN Bus Diagnostics Table ).
Whenever ECU is replaced, ensure that the CAN bus lines are normal.
If diagnosis code U1109 is set in ASC-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.
Before replacing the ECU, ensure that the communication circuit is normal.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if ASC-ECU cannot receive the signal sent from ETACS-ECU for a certain period.
PROBABLE CAUSES
Wiring harness or connector failure of CAN bus line
ASC-ECU malfunction
ETACS-ECU malfunction
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use 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 - CAN Bus Diagnostics Table ).
STEP 2. M.U.T.-III ETACS diagnosis code
Check if any diagnosis code is set to the ETACS-ECU.
Q.
Is the diagnosis code set?
Perform troubleshooting for ETACS-ECU (Refer to GROUP 54A - Troubleshooting/Diagnosis Code Chart ).
Go to Step 3.
STEP 3. M.U.T.-III other system diagnosis code
Check if diagnosis code No.U1109 is set to the Combination meter assembly.
Q.
Is the diagnosis code set?
Go to Step 4.
Go to Step 5.
STEP 4. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set .
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code No.U1109 set?
Replace the ETACS-ECU.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
STEP 5. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code No.U1109 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - CAN Bus Diagnostics Table 
).