Code No. U1073: Bus Off


caution If diagnosis code U1073 is output from engine-ECU <M/T> or engine-A/T-ECU <A/T> surely perform CAN busline diagnosis.
caution Replace ECU after certainly confirming that the communication circuits are normal.

TROUBLE JUDGMENT


Check Condition
Judgment Criterion
COMMENT ON TROUBLE SYMPTOM

PROBABLE CAUSE



DIAGNOSIS

STEP 1. M.U.T.-III CAN bus diagnostics

  • Using M.U.T.-III, perform CAN busline diagnosis.

Q. Is the check result normal?
Go to Step 2 .
Correct CAN busline (Refer to 54D - Diagnosis - Can Bus Diagnosis Table ), and then go to Step 3 .

STEP 2. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output from engine-ECU <M/T> or engine-A/T-ECU <A/T>.

  1. Erase the diagnosis codes being output.
  2. Ignition switch: "LOCK" (OFF) to ON
  3. Confirm whether the diagnosis codes are output.

Q. Are the diagnosis codes output?
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>. Then go to Step 3 .
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 3. M.U.T.-III diagnosis code
Reconfirm whether the diagnosis codes are output from engine-ECU <M/T> or engine-A/T-ECU <A/T>.

  1. Erase the diagnosis codes being output.
  2. Ignition switch: "LOCK" (OFF) to ON
  3. Confirm whether the diagnosis codes are output.

Q. Are the diagnosis codes output?
Go to Step 1 .
Check end.