Headlight Beam Level Control Actuator Circuit [09/2014 - 10/2018]: Procedure

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Lexus RC 350, 2018 Lexus RC 300, 2017 Lexus RC 350, 2017 Lexus RC 300, and 2017 Lexus RC 200t. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST USING TECHSTREAM

Connect the Techstream to the DLC3.
Start the engine.
Turn the Techstream on.
Enter the following menus: Body Electrical / HL AutoLeveling / Active Test.

Perform the Active Test according to the display on the Techstream.

Body Electrical > HL AutoLeveling > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Drive The Leveling Motor	Leveling motor upward or downward operation	Stop/Down/Up	Perform the Active Test with the engine started and vehicle stopped

Body Electrical > HL AutoLeveling > Active Test

Tester Display
Drive The Leveling Motor

Headlight leveling motors operate normally.

Result

Proceed to
OK
NG

Result:

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE [09/2014 - 11/2017] , or refer to PROBLEM SYMPTOMS TABLE [11/2017 - 10/2018]

Result:

See step 2

CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - HEADLIGHT LEVELING ECU ASSEMBLY)

Disconnect the A61 headlight leveling ECU assembly connector.
Disconnect the A30*1 or A1*2 headlight assembly connector.
1. *1: for LH Side
2. *2: for RH Side

Measure the resistance according to the value(s) in the table below.

Standard Resistance

FOR LH SIDE

Tester Connection	Condition	Specified Condition
A61-11 (LH+) - A30-4 (LHIG)	Always	Below 1 Ω
A61-18 (LHT) - A30-1 (LH T)	Always	Below 1 Ω
A61-24 (LH-) - A30-2 (LH E)	Always	Below 1 Ω
A61-11 (LH+) - Body ground	Always	10 kΩ or higher
A61-18 (LHT) - Body ground	Always	10 kΩ or higher
A61-24 (LH-) - Body ground	Always	10 kΩ or higher

FOR RH SIDE

Tester Connection	Condition	Specified Condition
A61-10 (RH+) - A1-4 (RHIG)	Always	Below 1 Ω
A61-17 (RHT) - A1-1 (RH T)	Always	Below 1 Ω
A61-23 (RH-) - A1-2 (RH E)	Always	Below 1 Ω
A61-10 (RH+) - Body ground	Always	10 kΩ or higher
A61-17 (RHT) - Body ground	Always	10 kΩ or higher
A61-23 (RH-) - Body ground	Always	10 kΩ or higher

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 3

CHECK HEADLIGHT CORD

Remove the headlight cord.
Refer to DISASSEMBLY [09/2014 - 10/2018]

Inspect the headlight cord.

Refer to INSPECTION [09/2014 - 10/2018]

Result

Proceed to
OK
NG

Result:

REPLACE HEADLIGHT CORD. Refer to DISASSEMBLY [09/2014 - 10/2018]

Result:

See step 4

CHECK HEADLIGHT LEVELING MOTOR

Replace the headlight leveling motor with a new or known good one.
Refer to DISASSEMBLY [09/2014 - 10/2018]

Perform the Active Test according to the display on the Techstream.

Body Electrical > HL AutoLeveling > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Drive The Leveling Motor	Leveling motor upward or downward operation	Stop/Down/Up	Perform the Active Test with the engine started and vehicle stopped

Body Electrical > HL AutoLeveling > Active Test

Tester Display
Drive The Leveling Motor

Headlight leveling motors operate normally.

Result

Proceed to
OK
NG

Result:

END (HEADLIGHT LEVELING MOTOR WAS DEFECTIVE)

Result:

REPLACE HEADLIGHT LEVELING ECU ASSEMBLY. Refer to REMOVAL [09/2014 - 10/2018]