DTC P0125: Insufficient Coolant Temperature for Closed Loop Fuel Control [11/2021 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125)
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Powertrain / Engine / Trouble Codes.
- Read the DTCs.
Powertrain > Engine > Trouble Codes
Result
Result Proceed to DTC P0125 is output A DTC P0125 and other DTCs are output B HINT:
If any DTCs other than P0125 are output, troubleshoot those DTCs first.
Result:
B
GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2021 - ]
Result:
A
See step 2
- INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY
- Inspect the water inlet with thermostat sub-assembly (thermostat opening temperature).
Refer to INSPECTION [11/2021 - ]
Result
Proceed to OK NG
Result:
NG
REPLACE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY. Refer to REMOVAL [11/2021 - ]
Result:
OK
See step 3
- Inspect the water inlet with thermostat sub-assembly (thermostat opening temperature).
- CHECK COOLING SYSTEM
- Check for defects in the cooling system that might cause the system to be too cold, such as abnormal cooling fan operation or any modifications.
HINT:
Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.
Refer to INITIALIZATION [11/2021 - ]
Result
Proceed to OK NG
Result:
OK
REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to REMOVAL [11/2021 - ]
Result:
NG
REPAIR OR REPLACE COOLING SYSTEM
- Check for defects in the cooling system that might cause the system to be too cold, such as abnormal cooling fan operation or any modifications.