Code No. U1122: Brake CAN data error


caution
  • If the EPS-ECU sets the diagnosis code No. U1122, 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


Current trouble
  • The ABS-ECU wheel speed sensor system, ASC-ECU itself, or EPS-ECU itself may be faulty.
Past trouble
  • Carry out diagnosis with particular emphasis on connectors and wiring harness between the ASC-ECU and the wheel speed sensor. For diagnosis procedures, refer to "How to Cope with Historic Trouble" (GROUP 00 - How to Use Troubleshooting/Inspection Service Points ).

PROBABLE CAUSES



  • Defective harness wire(s) or connector(s)
  • Malfunction of the ASC-ECU.
  • Malfunction of the EPS-ECU

DIAGNOSIS PROCEDURE


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



Q. Is the check result satisfactory?





STEP 2. Use M.U.T.-III to confirm a diagnosis code of other systems.



Q. Is the diagnosis code set?





STEP 3. Diagnosis code recheck



(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. U1122 is set as a current trouble.

Q. Is diagnosis code C1122 set?





STEP 4. Diagnosis code recheck



(1)Turn the electric motor switch to the "LOCK" (OFF) → "ON" position.
(2)Check if the diagnosis code No. U1122 is set as a current trouble.

Q. Is diagnosis code C1122 set?