Code No.U1700 SWS Communication Line


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.


















TROUBLE JUDGMENT



COMMENT ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of the column switch
  • Malfunction of the front-ECU
  • Malfunction of the CAN converter-ECU
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Check the following connectors.




  • D-420 ETACS-ECU connector
  • D-311 Column switch connector
  • A-09X Front-ECU connector
  • D-252 CAN converter-ECU connector

Q. Are all the connectors in good condition?





STEP 2. Check the following wiring harness.




  • Wiring harness from D-420 ETACS-ECU connector terminal No.59 to D-311 column switch connector terminal No.3
  • Wiring harness from D-420 ETACS-ECU connector terminal No.59 to A-09X front-ECU connector terminal No.22
  • Wiring harness from D-420 ETACS-ECU connector terminal No.59 to D-252 CAN converter-ECU connector terminal No.3
note Prior to the wiring harness inspection, check intermediate connectors D-241, and repair if necessary.

Q. Are all the wiring harness wires in good condition?





STEP 3. Check whether the diagnosis code is reset.



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

Q. Is the diagnosis code set?





STEP 4. Check whether the diagnosis code is reset.



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

Q. Is the diagnosis code set?





STEP 5. Check whether the diagnosis code is reset.



(1)Disconnect the CAN converter-ECU connector.
(2)Erase the diagnosis code.
(3)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(4)Check if diagnosis code is set.

Q. Is the diagnosis code set?





STEP 6. 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?