ODB-II Code P0125

[SmokinBBC]

I don't know if this is the right place to post this, if not....sorry. It's not a vette, but I could use the help.


I have a Code P0125. Insufficient coolant temp for closed loop fuel control.

It's a 2003 Ford Expedition, 5.4L. 116k miles

The eng temp guage started reading real low a while back. When driving on the highway, the guage will read even lower..just a tick above the lowest level.

I have erased the code, but it returns after about a week...no other codes, just this one.

Do you think that the thermostat is stuck open? It never seems to really warm up unless I'm sitting at idle for about 5 minutes. Fuel economy sucks worse than normal!

Thanks.

 

[Twin_Turbo]

Sounds like it's a stuck stat indeed.

 

[SmokinBBC]

Found this on the net:

A code P0125 may mean that one or more of the following has happened:

Insufficient warm up time
Low engine coolant level
Leaking or stuck open thermostat
Faulty coolant temperature sensor


I know it isn't the first or second...the thermostat is easy to change...the coolant temp sensor is located on the intake manifold and is a bitch to get at...

 

[Twin_Turbo]

fingers crossed then, usually that means you swap the stat and it turns out to be the sensor afterall.

usually when those go bad or the connection is corroded they give waaay too high resistance across the board and this would result in the engine running very rich, the black cloud kind.

 

[SmokinBBC]

fingers crossed then, usually that means you swap the stat and it turns out to be the sensor afterall.

usually when those go bad or the connection is corroded they give waaay too high resistance across the board and this would result in the engine running very rich, the black cloud kind.

Changed the stat. It is running warmer than it has previously. I'll drive it for a week to see if the code comes back.

I checked the wires..they look ok. If the code comes back, I'll check the connectons.

Doesn't run rich as far as I can tell. No exhaust smoke at all.