Problem Symptoms Table [10/2016 - 09/2020]
WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2020 Lexus IS 350, 2020 Lexus IS 300, 2019 Lexus IS 350, 2019 Lexus IS 300, and 2018 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If the No. 1 headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the No. 1 headlight ECU sub-assembly LH.
Refer to INITIALIZATION [10/2016 - 09/2020]
HINT:
- Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
- Inspect the fuses and relays related to this system before inspecting the suspected areas below.
AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM
| Symptom | Suspected Area | Link |
|---|---|---|
| Automatic headlight beam level control system does not operate (Left Headlight) | Headlight beam level control actuator circuit | Refer to Headlight Beam Level Control Actuator Circuit [10/2016 - 09/2020] |
| No. 1 Headlight ECU sub-assembly LH | Refer to REMOVAL [10/2016 - 09/2020] | |
| Automatic headlight beam level control system does not operate (Right Headlight) | Headlight beam level control actuator circuit | Refer to Headlight Beam Level Control Actuator Circuit [10/2016 - 09/2020] |
| No. 1 Headlight ECU sub-assembly RH | Refer to REMOVAL [10/2016 - 09/2020] | |
| Initialization cannot be performed | CAN communication system | Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2016 - 09/2018] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2018 - ] |
| No. 1 Headlight ECU sub-assembly LH | Refer to REMOVAL [10/2016 - 09/2020] |