Code No. U1073: Bus-off



caution
  • If the EPS-ECU sets the diagnosis code No. U1073, diagnose the CAN bus lines. If there is any fault in the CAN bus lines, an incorrect diagnosis code may be set.
  • Before replacing ECU, ensure that the communication circuit is normal.

TROUBLE JUDGEMENT




COMMENT ON TROUBLE SYMPTOM




PROBABLE CAUSES



  • Defective wire(s) or connector(s) in the CAN bus lines
  • Malfunction of the EPS-ECU

DIAGNOSIS PROCEDURE


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


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 lines. (Refer to GROUP 54C, Troubleshooting .)

STEP 2. Diagnosis code recheck


Recheck if the diagnosis code is set.
(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Start the electric motor unit.
(3)Check if the diagnosis code No. U1073 is set as a current trouble.

Q. Is the diagnosis code No. U1073 set?

Replace EPS-ECU.
Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)