Code No. U1109: ETACS CAN time-out


caution
  • When three minutes or more elapse since the electric motor switch is turned ON, the EPS-ECU may set diagnosis codes No. U1100, U1102, U1108, and U1109, and M.U.T.-III may show the diagnosis code status as the historic trouble.
  • If the EPS-ECU sets the diagnosis code No. U1109, diagnose the CAN bus lines. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set.
  • Before replacing ECU, ensure that the communication circuit is normal.

TROUBLE JUDGEMENT



COMMENT ON TROUBLE SYMPTOM


Current trouble
  • The wiring harness or connector in the CAN bus lines between the EPS-ECU and ETACS-ECU, the power supply system of the ETACS-ECU, or the EPS-ECU itself may be faulty.
Past trouble
  • If the diagnosis code No. U1109 is stored as a historic trouble, carry out the diagnosis with particular emphasis on the wiring harness and connector in the CAN bus lines between the EPS-ECU and ETACS-ECU as well as on the power supply system of the ETACS-ECU. For diagnosis procedures, refer to "How to treat past trouble" (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ).
    note In case of a historic trouble, the M.U.T.-III CAN bus diagnosis cannot find the problem even when there is an abnormality in the CAN bus. In this case, be sure to diagnose the CAN bus lines in the same manner as for "How to Cope with Intermittent Malfunction" (refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points ). You can narrow down the possible cause of the trouble by referring to the diagnosis code, which is set regarding the CAN communication-linked ECUs (refer to GROUP 54C - Explanation About the M.U.T.-III CAN Bus Diagnostics ).

PROBABLE CAUSES



  • Defective harness wire(s) or connector(s)
  • The ETACS-ECU may be defective
  • Malfunction of the EPS-ECU

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 lines. (Refer to GROUP 54C, Troubleshooting . ) After repairing the CAN bus lines, go to STEP 2.

STEP 2. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the ETACS-ECU sets a diagnosis code.

Q. Is the diagnosis code set?
Diagnose the ETACS-ECU. (Refer to GROUP 54A - Troubleshooting .)
Go to Step 3.

STEP 3. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Start the electric motor unit.
(3)Check if the diagnosis code No. U1109 is set as a current trouble.

Q. Is the diagnosis code No. U1109 set?
Replace the EPS-ECU (refer to ), and then go to Step 4.
Go to Step 4.

STEP 4. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. U1109 is set as a current trouble.

Q. Is the diagnosis code No. U1109 set?
Replace the ETACS-ECU.
The diagnosis is complete.