MIL Circuit [10/2018 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK THAT MIL IS ILLUMINATED
- Perform troubleshooting in accordance with the table below.
Result
MIL Condition Proceed to Illuminates → Turns off Power switch on (IG) → engine is started A Other than above - B
Result:
A
CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [10/2018 - ]
Result:
B
See step 2
- Perform troubleshooting in accordance with the table below.
- CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Check the communication between the Techstream and ECM.
HINT:
It can be checked using the "Engine" item of the Data List.
Result
Result Proceed to Communication is possible A Communication is not possible B
Result:
B
GO TO VC OUTPUT CIRCUIT. Refer to VC Output Circuit [10/2018 - ]
Result:
A
See step 3
- CHECK WHETHER DTC OUTPUT RECURS
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: System Select / Health Check.
- Check if any DTCs have been detected. Note down the detected DTCs.
Result
Result Proceed to DTCs are not output A Any DTCs is output B HINT:
Check for detected DTCs output from other ECUs which relate to the MIL.
Result:
B
REPAIR CIRCUIT INDICATED BY OUTPUT
Result:
A
See step 4
- PERFORM ACTIVE TEST USING TECHSTREAM
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Combination Meter / Active Test / Check Engine Warning.
Body Electrical > Combination Meter > Active Test
Tester Display Check Engine Warning - Check the status of the MIL while performing the Active Test.
Result
Result Proceed to Changes A Does not change B
Result:
A
REPLACE ECM. Refer to REMOVAL [10/2018 - 07/2022] Refer to REMOVAL [07/2022 - ]
Result:
B
REPLACE COMBINATION METER ASSEMBLY. Refer to REMOVAL [10/2018 - 07/2022] Refer to REMOVAL [07/2022 - ]