If diagnosis
code No.U1073 is set in the ETACS-ECU, diagnose the CAN bus lines.
Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.
TROUBLE JUDGMENT
Diagnosis code No.U1073 will be stored when the ETACS-ECU ceases CAN communication (bus
off) and then resumes the communication by turning the ignition switch to the "LOCK" (OFF) position.
COMMENT ON TROUBLE SYMPTOM
The wiring harness wire or connectors may have loose, corroded, or damaged terminals,
or terminals pushed back in the connector.
PROBABLE CAUSES
Damaged harness wires and connectors
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 3.
STEP 2. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)On completion, check that the diagnosis code is reset.
Q.
Is the check result normal?
If the trouble is solved, it is determined that there is an intermittent malfunction
such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Use Troubleshooting/Inspection
Service Points -
How to Cope with Intermittent Malfunctions ).
Replace the ETACS-ECU, and Then go to Step 3.
STEP 3. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set to the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting 
).
On completion, go to Step 3.