Causes and Fixes P0125 Code: Insufficient Coolant Temperature for Closed Loop Fuel Control

How to fix P0125 Code: Insufficient Coolant Temperature for Closed Loop Fuel Control
A P0125 Code when the computer (ECM/PCM) sees an issue with the engine not reaching its operating temperature.
A closed loop is when the computer (ECM/PCM) uses the oxygen sensor for feedback.
An open loop is when the computer (ECM/PCM) does Not use the oxygen sensor for feedback. An open loop is normal when the engine first starts. Once the engine warms up, it should go into a closed loop.
Cause of a P0125 code include a bad ECT sensor, low coolant levels, and a stuck open thermostat.
Possible Causes of a P0125 Code:
Low Coolant or Other Coolant Issues
Bad Engine Coolant Temperature (ECT) sensor
ECT Sensor Wiring Issue
Thermostat Stuck Open
Very Cold Weather
By using this information user assumes all risk of use.

[@kalpeshkapadia4623]

Thanks sir

[@figgiefigueroa7372]

Thanks for sharing your knowledge!!!!
My car did the 200,000 miles and im changing all the sensors.
But mine says is running too rich.

[@gera-FDP6900needed]

The first time after an engine swap my new basic engine overheated. It won't start. I have fixD diagnostics tool & the only thing that it says is 'nothing found' & 'open loop'

[@RoofboxCamping]

My 2000 lexus is200 is stuck in open loop and I can't figure out how to fix it at all