2013 jku 168k miles. Electric fan is running wide open at all times when the engine is running. A few seconds after first starting the engine the fan is running at the highest rpm I've ever heard it. So cold engine or hot same thing, coolant is good, no over heating, operating at normal temp. Anyone have a thought on what I need to be looking for. I do have another issue but being the coolant temp sensor has been causing an error, coolant temp too low. That error has been going on for about a year. The fan just started last week.

 

clear the code and i bet that fan stops. i literally just helped neighbor with this over the weekend on their tahoe. they had a whole slew of codes but i spoted a P0128. as soon as i cleared all those codes the truck's fan was back to normal. in his case i think it was thrown as a fluke. coolant gauage wouldn't register and truck didn't know what the temp was so it freaked out and tried to prevent overheating. in your situation you have an active code related to the cooling system and a fan that is running on high. i think there could be a chance that the sensor had a blip and failed to log a temperature at all, which the computer would not have liked. Clearing codes to see what comes back should always be step 1 IMO. That might not be it, but it's so simple as first troubleshooting step.

 

Unfortunately resetting the code didn't work. I had thought of that and tried before, just failed to put it in my post above. Thanks for assistance!