Headlight Leveling ECU Power Source 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.
- READ VALUE USING TECHSTREAM
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / HL AutoLeveling / Data List.
- Read the Data List according to the display on the Techstream.
Body Electrical > HL AutoLeveling > Data List
Tester Display Measurement Item Range Normal Condition Diagnostic Note +B IG power supply voltage value 0.00 to 19.75 V 11.00 to 14.00 V - Body Electrical > HL AutoLeveling > Data List
Tester Display +B OK
Normal condition listed above is displayed.
Result
Proceed to OK NG
Result:
OK
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:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (BATTERY - HEADLIGHT LEVELING ECU ASSEMBLY)
- Disconnect the A61 headlight leveling ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A61-1 (IG) - Body ground Engine switch on (IG) 11 to 14 V A61-1 (IG) - Body ground Engine switch off Below 1 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - BODY GROUND)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A61-9 (E1) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE HEADLIGHT LEVELING ECU ASSEMBLY. Refer to REMOVAL [09/2014 - 10/2018]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- Measure the resistance according to the value(s) in the table below.