OBD Code PO125
 

2000 Expedition, 4.6L Windsor is throwing code PO125- "Insufficient coolant temp for closed loop fuel control." The engine itself eventually warms up, but the temp guage never moves. Is this just a sensor malfunction?

You need a new thermostat.

The same thing happened to my 5.4L. The engine temperature would never get above 167 degrees in the winter and I got the same code. I installed a new thermostat and now I'm nice and warm with an engine temperature of 192. :)

Smae thing hapened to mine, installed a new tstat and everything is good now.

I'm having the same as many here. The PO125 code popped and my ALLDATA wants my to trouble shoot pages worth of wires and harnesses. So the masses here say remove and replace thermostat and I should be OK...RIGHT?!? I have the 5.4L F150 with about 105K. PLEASE HELP my baby.

Come back AFTER you've followed the recommendations....

is your truck warming up? or is it just the gauge that's not moving?

I can say it's warmed up. I was traveling home from work 20 minutes on the I15 when it came on. I did notice the temp gauge alittle lower than normal.

was it blowing warm before the gauge started working? trying to figure out if it's your t-stat or your temp sender

It's not the sender. It's a failure of the engine to reach operating temp within the allotted time.

if the sender was not working then the pcm wouldn't know when the engine got to temp

No it don't blow hot air right away, but warmed up before the gauge moved. But when selected to warm it blows hot air and cool when in cool.

Did you change the thermostat yet?

The problem code is due to the engine not warming up as fast as it should.

When you find one of these trucks where the ECT or the CHT is responsible for this code instead of low coolant or a leaky/stuck open thermostat, you let us know.

This is a simple and inexpensive repair. Just go do it.

this is out of fords workshop manual, I guess you never bother to get to the bottom of the list

Diagnostic Trouble Code (DTC) P0125 indicates the CHT sensor has not achieved the required temperature level to enter closed loop operating conditions within a specified amount of time after starting engine. This DTC will light the MIL.
Possible causes:

• Insufficient warm up time.
• Leaky or stuck open thermostat.
• Low engine coolant level.
• Malfunctioning CHT sensor.