Before replacing the ECU, ensure that the communication circuit is normal.
TROUBLE JUDGMENT
The headlamp automatic levelling ECU receives a vehicle height signal from the front and rear height sensors and calculates the headlamp levelling pitch angle. If an abnormal pitch angle is calculated, diagnosis code No.24 is set.
COMMENTS ON TROUBLE SYMPTOM
The front height sensor, the rear height sensor or the headlamp automatic levelling ECU may have a problem.
PROBABLE CAUSES
Malfunction of the front height sensor
Malfunction of the rear height sensor
Malfunction of the headlamp automatic levelling ECU
Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. Connector check: A-05 front height sensor connector
Q.
Is the check result normal?
Go to Step 2.
Repair the defective connector.
STEP 2. Front height sensor check
Check that the front height sensor is normal (Refer to ).
Q.
Is the check result normal?
Go to Step 3.
Replace the front height sensor.
STEP 3. Check whether the diagnosis code is reset.
STEP 8. Check whether the diagnosis code is reset.
Q.
Is diagnosis code No. 24 set?
Replace the headlamp automatic levelling ECU.
The trouble can be an intermittent malfunction (Refer to GROUP 00 -
How to use Troubleshooting/inspection Service Points -
How to Cope with Intermittent Malfunction ).