Ok, my X has already thrown me this code twice now in less than a week. P0125 ‘Insufficient Coolant Temperature For Closed Loop Fuel Control’ What dose this mean for a shade tree mechanic like myself? Could it be a bad coolant temp sensor? Thx For any info.

 

Hi,

Got this one about a month ago driving home on a very cold night in northern NJ. Seems my thermostat was just beginning to go, and the CEL and code would only happen on the coldest nights when the engine didn't reach operating temperature fast enough for the emissions control system's liking.

Got a new thermostat for $8 and the extra o-ring for $6, and about a half hour later all was well again. The first time I drove it I noticed that the temperature gauge read higher, sooner, and stays pretty solid in the middle of the range all the time now now matter how cold it is outside. Before, it would fluctuate down towards "C" on a very cold day, but not enough to make me suspect a failing thermostat without the code.

There may be other causes for this code, but this is the first place I'd look.

Good luck!

Ed
2000 F150 XL 4x4, gettin' close to 100k mi.

 

Yep, thermostat time....

Steve

 

That's what it sounds like to me.