Code No.U1100 Engine-ECU Time-out (Related to Engine)


caution
  • If diagnosis code U1100 is set in the multi display station, always diagnose the CAN bus lines.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.

TROUBLE JUDGMENT



COMMENTS ON TROUBLE SYMPTOM


Current trouble
  • Connector(s) or wiring harness in the CAN bus lines between the engine-ECU and the multi display station, the power supply system to the multi display station, the multi display station itself, or the engine-ECU may be defective.
Past trouble
  • Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the engine-ECU and the multi display station, and the power supply system to the engine-ECU. For diagnosis procedures, refer to "How to cope with past trouble" (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points ).
    note For a past trouble, you may not find it by the M.U.T.-III CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ). and check the CAN bus lines. You can narrow down the possible cause of the trouble by referring to the diagnosis code, which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C, Explanation about the M.U.T.-III CAN Bus Diagnostics ).

POSSIBLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of engine-ECU
  • Malfunction of multi display station

DIAGNOSIS PROCEDURE


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



Q. Is the check result satisfactory?





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



Q. Is the diagnosis code set?





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




    ETACS-ECU

    • Code No.U1100: engine-ECU time-out (related to Engine)
    A/C-ECU

    • Code No.U1100: engine-ECU time-out (related to Engine)

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 to "ON" position.
(3)Check if the diagnosis code is set.

Q. Is the check result satisfactory?





STEP 5. Check whether the diagnosis code is reset.



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

Q. Is the check result satisfactory?





STEP 6. Check whether the diagnosis code is reset.



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

Q. Is the check result satisfactory?