Code No.03 Communication Error with Front-ECU

caution

If diagnosis code No.03 is set in the ETACS-ECU, diagnose the CAN bus lines.

TROUBLE JUDGMENT

The ETACS-ECU communicates with the front-ECU through the SWS communication line. If there is any trouble in that communication, diagnosis code No.03 will be set.

COMMENTS ON TROUBLE SYMPTOM

The front-ECU, the ETACS-ECU, connector(s), or wiring harness between the two may be defective.

PROBABLE CAUSES

Malfunction of the front-ECU
Malfunction of the ETACS-ECU
Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

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

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 line (Refer to GROUP 54D - Troubleshooting ).

STEP 2. Check whether the diagnosis code is reset.

Check again if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Ignition switch: LOCK (OFF) position to ON

(3)On completion, check that the diagnosis code is not reset.

Q. Is the check result normal?

	If a trouble is solved, it is determined that there is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).

	Go to Step 3.

STEP 3. ECU check by using the SWS monitor

Check that the power supply and earth lines to the ETACS-ECU and the front-ECU and the SWS communication lines are normal.

Ignition switch: OFF

ECUS TO BE CHECKED

Front ECU
ETACS ECU

OK: "OK" are displayed for all the items

Q. Are the check result normal?

	YES <Normal conditions are displayed for all the items.> : Intermittent malfunction (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).

	NO <"NG" is displayed on the "ETACS ECU" menu.> : Refer to Inspection Procedure 2 "Communication with the ETACS-ECU is not possible ."

	NO <"NG" is displayed on the "FRONT ECU" menu.> : Refer to Inspection Procedure 3 "Communication with the front-ECU is not possible ."