Inspection Procedure 2: One of the automatic levellings does not work.



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


When one of the automatic levellings does not work, the wiring harness and connector(s) between the ETACS-ECU and the headlamp assembly (headlamp levelling unit) may have a problem.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Headlamp levelling unit check


Perform a levelling motor drive test of the headlamp levelling unit to check that the motor is driven. Refer to .

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 Malfunctions ).

NO (The left levelling motor is not driven.) : Go to Step 2

NO (The right levelling motor is not driven.) : Go to Step 5

STEP 2. Check of open circuit in (MBL, MGL, MSL) line between ETACS-ECU connector and headlamp assembly (LH) connector.


Q. Is the check result normal?



Repair the connector(s) or wiring harness.

STEP 3. M.U.T.-III data list


(1)Disconnect the headlamp assembly (LH) and (RH) connector.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
Item No.
Item name
Normal condition
Item 418
A/L actuator output voltage
Indicates the voltage value of system voltage within the range of 20 to 80%.
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 4

Go to Step 8

STEP 4. Check the headlamp assembly (LH).


Check the headlamp assembly (LH) for internal failure.
(1)Disconnect the headlamp assembly (RH) connector.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Perform the drive test using the M.U.T.-III. Refer to .

Q. Is the check result normal?

Go to Step 8

Replace the headlamp assembly (LH).

STEP 5. Check of short to power supply, short to earth, and open circuit in (MBR, MGR, MSR) line between ETACS-ECU connector and headlamp assembly (RH) connector.


Q. Is the check result normal?



Repair the connector(s) or wiring harness.

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


(1)Disconnect the headlamp assembly (LH) and (RH) connector.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
Item No.
Item name
Normal condition
Item 418
A/L actuator output voltage
Indicates the voltage value of system voltage within the range of 20 to 80%.
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 7

Go to Step 8

STEP 7. Check the headlamp assembly (RH).


Check the headlamp assembly (RH) for internal failure.
(1)Disconnect the headlamp assembly (LH) connector.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Perform the drive test using the M.U.T.-III. Refer to .

Q. Is the check result normal?

Go to Step 8

Replace the headlamp assembly (RH).

STEP 8. Retest the system


Check that the automatic levelling of the right headlamp operates 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.