Old thread but it's the most relevant to my problem.
This last month it's been cold here in WA. state, between 4 and 20 degrees f. The CEL will come on, I check the codes, they have been p118 p0117 and another code can't remember off the top of my head. p112B I think. They have to do with coolant temp sensor and too rich at idle. I figure it's too rich at idle due to the car thinking it's constantly in warm up mode. Drives fine and can clear code but comes back a week later. I have cleaned the MAF, IAT sensor and air filter as well running non ethanol gas. The CEL had been gone since I cleared it Saturday morning and came back on this morning after driving to work. Took the long way to work about 20 minutes, so it's warmed up and no light the entire time. Right before I turned the car off the light came back on. Is all this related to it being so cold?
Randomly, twice, the fan will come on right after start up, the engine's cold after sitting overnight. It will stay on if I shut the car off a minute later, but if I get up to op temperature it functions as normal, no fan on after shut down. I don't want to replace the coolant temp sensor if its not bad.
I have also replaced the thermostat housing twice so I'm positive it's not leaking and there is no air in the system as I've checked twice this last week and the air is hot.
I am stumped as to what it could be. Any help or suggestions would be greatly appreciated. Thanks.

 

Just an update, we got the cold climate version in stock in bremmen parts, Genuine MINI version is nla https://www.ecstuning.com/Search/SiteSearch/ES4660507/