Code No.U0121 ABS/ASC CAN timeout


caution
  • If the diagnosis code No. U0121 is set, be sure to diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

DIAGNOSTIC FUNCTION



JUDGEMENT CRITERIA



PROBABLE CAUSES



  • Malfunction of the CAN bus
  • Malfunction of ASC-ECU
  • ASC-ECU power supply circuit malfunction
  • Malfunction of the LDW-ECU

DIAGNOSIS PROCEDURE


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



Q. Is the check result normal?





STEP 2. M.U.T.-III other system diagnosis code



Q. Is the diagnosis code set?





STEP 3. Check the M.U.T.-III Diagnosis code for other systems




    ETACS-ECU

    • Code No.U0121: ABS/ASC CAN timeout

Q. Is the diagnosis code set?





STEP 4. Check whether the diagnosis code is reset.



(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?





STEP 5. Check whether the diagnosis code is reset.



(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?