Inspection Procedure 2: None of the high-beam headlamps illuminate.

caution

Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)

COMMENTS ON TROUBLE SYMPTOM

If both headlamps (high-beam) do not illuminate normally, the headlamp switch input circuit, headlamp relay (HI), or ETACS-ECU may have a problem.

PROBABLE CAUSES

Malfunction of column switch
Malfunction of headlamp relay (HI)
Malfunction of the ETACS-ECU
Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Check if diagnosis code is set to the ETACS-ECU.

Q. Is the diagnosis code set?

Troubleshoot the ETACS-ECU. Refer to

Go to Step 2.

STEP 2. M.U.T.-III data list

Use the ETACS-ECU service data to check the signal related to the operation of headlamp function.

Headlamp switch to ON.

Item No.	Item name	Normal condition
Item 341	Head lamp switch	ON

OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 3.

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

STEP 3. Headlamp relay (HI) check

Refer to

Q. Is the check result normal?

Go to Step 4.

Replace the headlamp relay (HI).

STEP 4. Voltage measurement at the headlamp relay (HI) connector

(1)Remove the headlamp relay (HI), and measure at the relay box side.

(2)Measure the voltage between headlamp relay (HI) connector (power supply terminal) and the body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 5.

Go to Step 6.

STEP 5. Check of open circuit in HHI line between ETACS-ECU connector and headlamp relay (HI) connector

Q. Is the check result normal?

Go to Step 7.

Repair the connector(s) or wiring harness.

STEP 6. Check of open circuit in power supply line between fusible link and headlamp relay (HI) connector

Q. Is the check result normal?

Go to Step 7.

Repair the connector(s) or wiring harness.

STEP 7. Retest the system

Check that the headlamps (high-beam) illuminate normally.

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 ETACS-ECU.