U1121 – Failure information on engine-A-M-T-ECU (related to automated manual transmission) MMC Colt


  • If diagnosis code No.U1121 is set in the ETACS-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

  • TROUBLE JUDGMENT


    COMMENT ON TROUBLE SYMPTOM

  • Connector(s), wiring harness in the CAN bus lines, the engine-A-M/T-ECU, allshift lever, or ETACS-ECU may be defective.

  • PROBABLE CAUSES

  • Malfunction of the engine-A-M/T-ECU
  • Malfunction of the allshift lever
  • Malfunction of the ETACS-ECU

  • DIAGNOSIS PROCEDURE

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

    Q. Is the check result normal?

    STEP 2. Check the diagnosis code of the engine-A-M/T-ECU

    Q. Is the diagnosis code set?

    STEP 3. M.U.T.-III other system diagnosis code

  • Combination meter
    U1121: Failure information on engine-ECU <M/T> or engine-A-M/T-ECU <Automated manual transmission> (related to engine)
  • Q. Is the diagnosis code set?

    STEP 4. Check whether the diagnosis code is reset.

    Q. Is the diagnosis code set?

    STEP 5. Check whether the diagnosis code is reset.

    Q. Is the diagnosis code set?

    STEP 6. Check whether the diagnosis code is reset.

    Q. Is the diagnosis code set?

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