Code No.U1073 Bus off

caution

If diagnosis code U1073 is set in the combination meter, always diagnose the CAN bus lines.
Whenever the ECU is replaced, ensure that the communication circuit is normal.

TROUBLE JUDGMENT

Diagnosis code No.U1073 will be stored when the combination meter ceases CAN communication (bus off) and then resumes the communication by turning the ignition switch to the "LOCK" (OFF) position.

COMMENTS ON TROUBLE SYMPTOM

The wiring harness wire or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the combination meter may be defective.

PROBABLE CAUSES

Damaged harness wires and connectors
Malfunction of combination meter

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 54D - Troubleshooting

). Repair the CAN bus line and go to Step 3.

STEP 2. Check whether the diagnosis code is reset.

Recheck if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Turn the ignition switch to "ON" position.

(3)On completion, check that the diagnosis code is not 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

Replace combination meter and then go to Step 3.

STEP 3. Check whether the diagnosis code is reset.

Recheck if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Turn the ignition switch to "ON" position.

(3)On completion, check that the diagnosis code is not reset.

Q. Is the check result normal?

The procedure is complete.

Go to Step 1.