Inspection Procedure 4: The LDW is cancelled together with a visual warning temporarily.

caution

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

COMMENTS ON TROUBLE SYMPTOM

If the LDW is cancelled together with a visual warning temporarily, the CAN bus line, the engine system, the ASC system, the steering wheel sensor, the ETACS-ECU or the LDW-ECU may be defective.

PROBABLE CAUSES

Malfunction of the CAN bus lines
Defective engine system
Defective ASC system
Defective steering wheel sensor
The ETACS-ECU may be defective
Malfunction of the LDW-ECU

DIAGNOSIS PROCEDURE

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

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

). On completion, go to Step 2.

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

Check if diagnosis code is set to the LDW.

Q. Is the diagnosis code set?

Troubleshoot the LDW-ECU. Refer to

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code

Check if diagnosis code is set to the ASC-ECU and engine-ECU.

Q. Is the diagnosis code set?

Set to the engine-ECU. : Troubleshoot the engine (Refer to GROUP 13A - Diagnosis Code Chart

).

Set to the ASC-ECU. : Troubleshoot the ASC. Refer to GROUP 35C - Troubleshooting

.

The diagnosis code is not set.

: Go to Step 4.

STEP 4. M.U.T.-III data list

Check the LDW-ECU service data.

Vehicle stopped (the steering wheel is in the neutral position)

Item No.	Item name	Normal condition
Item 13	Steering angle	-6 to 6 deg

Running

Item No.	Item name	Normal condition
Item 13	Steering angle	Nearly the same as the steering wheel operation angle <-720 to 720 deg (LDW-ECU normal detection value)>

OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 5.

Replace the steering wheel sensor.

STEP 5. M.U.T.-III other system service data

Check the ETACS-ECU system data list.

Release the brake pedal.

Item No.	Item name	Normal condition
Item 290	Stop lamp switch	OFF

OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 6.

Troubleshoot the stop lamp. Refer to Inspection Procedure 12 "The stop lamps do not illuminate or go out normally."

STEP 6. Retest the system

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction

Replace the LDW-ECU.