Diagnosis code No. U1109 is set when the combination meter cannot communicate with the ETACS-ECU for more than 0.5 second.
COMMENTS ON TROUBLE SYMPTOM
The M.U.T.-III shows a diagnosis code status as active.
Connector(s) or wiring harness in the CAN bus lines between the combination meter and the ETACS-ECU, the power supply circuits to the ETACS-ECU itself may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
If diagnosis code No.U1109 is set as past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the CAN bus lines between the combination meter and the ETACS-ECU, or power supply to the ETACS-ECU. For diagnosis procedures, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble .
note
For a past trouble, you cannot find it by the M.U.T.-III CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions and check the CAN bus lines. You can narrow down the probable cause of the trouble by referring to the diagnosis code, which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C - CAN Bus Line Diagnostic Flow ).
PROBABLE CAUSES
Malfunction of the combination meter
Malfunction of the ETACS-ECU
Malfunction of wiring harness or connector
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
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 ). On completion, go to Step 6.
STEP 2. Check the M.U.T.-III Diagnosis code for other systems
Check that the ETACS-ECU sets a diagnosis code.
Q.
Is the diagnosis code set?
Diagnose the ETACS-ECU (Refer to ). On completion, go to Step 6.
Go to Step 3
STEP 3. Check the M.U.T.-III Diagnosis code for other systems
Check if the diagnosis code No. U1109 is set to MCU.
Q.
Is the diagnosis code set?
Go to Step 4
Go to Step 5
STEP 4. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the combination meter.
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.
Q.
Is the diagnosis code set?
Replace the ETACS-ECU. Then, carry out the CAN bus diagnostics.Then go to Step 6 .
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the ETACS-ECU and the combination meter (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.
Check again if the diagnosis code is set to the combination meter.
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.
Q.
Is the diagnosis code set?
Replace the combination meter. Then, carry out the CAN bus diagnostics. Then go to Step 6 .
A poor connection, open circuit or other intermittent malfunction is present in the CAN bus lines between the ETACS-ECU and the combination meter (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
STEP 6. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set to the combination meter.
(1)Erase the diagnosis code.
(2)Turn the electric motor switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.
.
Go to Step 2
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting 