Inspection Procedure 2: ABS warning lamp does not illuminate when ignition switch is turned to the ON position (engine stopped).

caution

If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
Before replacing the ECU, ensure that the communication circuit is normal.

OPERATION

ABS-ECU sends the illumination request signal of the ABS warning lamp to the combination meter through ETACS-ECU via CAN communication.
ABS-ECU illuminates the ABS warning lamp via ETACS-ECU for approximately 3 seconds for valve check with the ignition switch turned to the ON position.

COMMENTS ON TROUBLE SYMPTOM

This may be caused by faults in the CAN bus line, ETACS-ECU, combination meter or ABS-ECU.

PROBABLE CAUSES

Damaged wiring harness and connectors
Malfunction of ETACS-ECU
Combination meter malfunction
ABS-ECU malfunction
Malfunction of coding data for ETACS-ECU

DIAGNOSIS PROCEDURE

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

Use 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 - CAN Bus Diagnostics Table .). Then go to Step 7.

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

Use M.U.T.-III to check the diagnosis code for the ABS system.

Q. Is the diagnosis code set?

	Carry out the diagnosis for the diagnosis code (Refer to ).

	Go to Step 3.

STEP 3. M.U.T.-III actuator test

Perform the following actuator test by the combination meter system, and check if the ABS warning lamp illuminates (Refer to GROUP 54A - Combination Meter/Actuator Test Table

Item No.07: Indicator 1

Q. Is the check result normal?

	Go to Step 4.

	Diagnose the combination meter (Refer to GROUP 54A - Combination Meter/Trouble Symptom Chart ). Then go to Step 7.

STEP 4. ETACS-ECU coding data check

Perform the variant coding to the ETACS-ECU.

Q. Is the check result normal?

	Go to Step 5.

	Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU ), and then go to Step 7.

STEP 5. M.U.T.-III other diagnosis code

Use M.U.T.-III to check that other diagnosis code is set in the combination meter system.

Q. Is the diagnosis code set?

	Diagnose the combination meter (Refer to GROUP 54A - Troubleshooting ). Then go to Step 7.

	Go to Step 6.

STEP 6. Retest the system.

Q. Does the ABS warning lamp turn ON and OFF normally?

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunction ).

	Replace the hydraulic unit [(integrated with ABS-ECU) Refer to ]. Then go to Step 7.

STEP 7. Retest the system.

Q. Does the ABS warning lamp turn ON and OFF normally?

	This diagnosis is complete.

	Return to Step 1.