Inspection Procedure 3: Electric power steering warning lamp has illuminated, but the diagnosis code is not stored.








COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Damaged harness wires and connectors
  • Malfunction of the on board charger/on board transformer
  • 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 .) Then, go to Step 2.

STEP 2. Connector and terminal check

  • Check the B-114 EPS-ECU connector terminal No. 2, No. 3, and junction block connector for improper engagement, terminal damage, or drawn-in terminal to the connector case.

Q. Are the connector and terminal normal?
Go to Step 3.
Repair the damaged connector.

STEP 3. Voltage measurement at B-114 EPS-ECU connector

  • Disconnect the connector and measure at the wiring harness side.
  • Turn the electric motor switch to the "ON" position.
  • Measure the voltage between B-114 EPS-ECU connector terminal No. 3 and the body earth.
OK: Battery voltage

Q. Is the check result normal?
Go to Step 4.
Go to Step 6.

STEP 4. Voltage measurement at B-114 EPS-ECU connector

  • Disconnect the connector and measure at the wiring harness side.
  • Measure the voltage between B-114 EPS-ECU connector terminal No. 2 and the body earth.
OK: Battery voltage

Q. Is the check result normal?
Go to Step 5.
Go to Step 7.

STEP 5. Measure the resistance at B-114 EPS-ECU connector.

  • Disconnect the connector and measure at the wiring harness side.
  • Measure the resistance between B-114 EPS-ECU connector terminal No. 1 and the body earth.
OK: Continuity exists (2 Ω or less).

Q. Is the check result normal?
Go to Step 9.
Go to Step 8.

STEP 6. Wiring harness check
note Before the wiring harness inspection, check the junction block connectors B-302 and B-306, and repair if necessary.

  • Check the wiring harness between B-114 EPS-ECU connector and junction block connector for any abnormality.

Q. Is the wiring harness normal?
Go to Step 11.
Repair the wiring harness.

STEP 7. Wiring harness check

  • Check the wiring harness between B-114 EPS-ECU connector and the fusible link No. 23 for any abnormality.

Q. Is the wiring harness normal?
Go to Step 11.
Repair the wiring harness.

STEP 8. Wiring harness check

  • Check the wiring harness between B-114 EPS-ECU connector and the body earth for any abnormality.

Q. Is the wiring harness normal?
Go to Step 11.
Repair the wiring harness.

STEP 9. Auxiliary battery check

  • Refer to GROUP 54A - Battery Test .

Q. Is the auxiliary battery normal?
Go to Step 10.
Charge or replace the auxiliary battery.

STEP 10. Charging system check

  • Check if the diagnosis code is set to the on board charger.

Q. Is the diagnosis code set?
Carry out the troubleshooting on the on board charger (Refer to GROUP 54D - On Board Charger/DC-DC Converter - Diagnosis Code Chart ).
Go to Step 11.

STEP 11. Check the trouble symptom.

Q. Is the check result normal?
An intermittent malfunction may be present. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace EPS-ECU.(Refer to .)