Code No. U1120: EV-ECU CAN data error


caution
  • If the EPS-ECU sets the diagnosis code No. U1120, 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 EV-ECU itself or EPS-ECU itself may be faulty.
Past trouble
  • Carry out the diagnosis with particular emphasis on the EV-ECU. 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 EV-ECU
  • 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. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if the diagnosis code is set to the EV-ECU.

Q. Is the diagnosis code set?
Perform the troubleshooting for the EV-ECU (refer to group 54D - EV-ECU - Diagnosis Code Chart ).
Go to Step 3.

STEP 3. Use M.U.T.-III to confirm a diagnosis code of other systems.
Check if a diagnosis code, which relates to the CAN communication-linked systems below, is set.

  • Combination meter
  • EV system-related CAN communication fail information

Q. Is the diagnosis code set?
Go to Step 4.
Go to Step 5.

STEP 4. 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. U1120 is set as a current trouble.

Q. Is the diagnosis code No. U1120 set?
Replace the EV-ECU.
An intermittent malfunction may be present. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)

STEP 5. 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. U1120 is set as a current trouble.

Q. Is the diagnosis code No. U1120 set?
Replace EPS-ECU.
An intermittent malfunction may be present. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)