Thermostat/heater circuit open trouble code

[mjc457]

Is the gasket you are talking about the rubber piece that is already inserted on the side of the thermostat housing or is there also supposed to be a gasket for the oil cooler pipe at the bottom front of the thermostat where there are two bolts connecting the metal pipe to the t stat?

 

[Z71]

Is the gasket you are talking about the rubber piece that is already inserted on the side of the thermostat housing or is there also supposed to be a gasket for the oil cooler pipe at the bottom front of the thermostat where there are two bolts connecting the metal pipe to the t stat?

Yes, there is a separate oil pipe gasket.

 

[Workmany2k]

I have the same issue, light on/Engine fan always on

I have replaced two thermostats. After two or three days fan comes back on and check engine light. Says the same error as first thread. Fist part I just bought the front part with thermostat. Two days lights on fan was on. It was really cold so the only way to get heat was take off battery terminal and after a few days of working fine it would kick the code and the fan on. So I bought the entire housing. I did buy the parts cheap. From amazon and another parts website. I figured no way both parts suck as some people wrote that it fixed there fan always on issue. But for me it only works two days then I have to clear codes or take off battery terminal. I had a person I know hook up a dealer tester as they work at one and scan entire car. With code deleted everything works like a charm. Then two days later it comes back. When he scanned it it was mostly the same thing. Thermostat but I would figure it would be bad all the time not work fine for a few days and stop. I’m just confused if I should get a new battery, it’s never been replaced. 2013 sonic 123k miles. Could it be a short in one of the plugs that snap into the thermostat housing. I’ve pulled fan relays and fan still runs. I’m just not sure if I should go through the trouble this time of another thermostat unit or if it might be the computer or what at this point.

 

[Workmany2k]

Timing belt and water pump and serpentine belt and pulleys changed about 109k miles. I hear a little squeak coming from serpentine belt / water pump area after over night sit. Not sure if that’s anything or not also. If it’s a battery maybe not getting a good ground causing the code to pop up? Just at wits end on this.