Diagnosis code No. U1102 is set when the combination meter cannot communicate with the ASC-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 ASC-ECU, the power supply circuits to the ASC-ECU itself may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
If diagnosis code No.U1102 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
ASC-ECU, or power supply to the ASC-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 ASC-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 ASC-ECU sets a diagnosis code.
Q.
Is the diagnosis code set?
Diagnose the ASC-ECU (Refer to GROUP 35C - Troubleshooting ).
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. U1102 is set to ETACS-ECU.
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 ASC-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 ASC-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 ASC-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 