Inspection Procedure 3: The LDW does not enter the warning monitor mode under some circumstances.

caution

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

COMMENTS ON TROUBLE SYMPTOM

When the LDW does not enter the warning monitor mode, the windshield glass, the stop lamp switch circuit, the column switch circuit, the turn signal lamp circuit, the ETACS-ECU or the LDW-ECU may be defective.

PROBABLE CAUSES

Faults on the windshield glass (such as scratch, cracks, contamination or drain drops on the glass surface)
Defective stop lamp switch circuit
Defective column switch circuit
Defective turn signal lamp circuit
The ETACS-ECU may be defective
Malfunction of the LDW-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the camera mounted surface on the windshield.

Visually check the LDW camera mounted surface on the windshield for scratch, cracks, contamination or drain drops.

Q. Is the check result normal?

Go to Step 2.

Windshield glass replacement (Refer to GROUP 42A - windshield glass removal and installation

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 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 4.

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

STEP 4. M.U.T.-III other system service data

Check the ETACS-ECU system data list.

Turn-signal lamp switch: LH or RH position.

Item No.	Item name	Normal condition
Item 343	Turn switch left	ON
Item 344	Turn switch right	ON

Turn-signal lamp switch: Except LH or RH position.

Item No.	Item name	Normal condition
Item 343	Turn switch left	OFF
Item 344	Turn switch right	OFF

OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 5.

Troubleshoot the ETACS. Refer to Inspection Procedure 11 "The column switch signal is not received."

STEP 5. Operate the turn signal lamp switch check

Operate the turn signal lamp switch to LH or RH side to check that the turn signal lamps illuminate and go out.

Q. Is the check result normal?

Go to Step 6.

Troubleshoot the turn signal lamp (Refer to Headlamp - Diagnosis Code Chart

STEP 6. M.U.T.-III data list

Check the LDW-ECU service data.

The vehicle is being driven on the road where lane division lines are clear with the LDW activated.

Item No.	Item name	Normal condition
Item 103	Lane Detection (R)	ON
Item 104	Lane Detection (L)	ON

The vehicle is being driven on the road where lane division lines are not clear with the LDW activated.

Item No.	Item name	Normal condition
Item 103	Lane Detection (R)	OFF
Item 104	Lane Detection (L)	OFF

OK: Normal condition is displayed.

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.