I have a 2015 Chrysler 200 2.4L giving me a code P0128 just outside the warranty period. From what I understand this is a common problem and the thermostat housing has to be replace. I have purchased the part from the local dealer and will be replacing it.

My question are as follows:

Does this usually fix the problem or are there other things to check? Car runs fine just does not get up to temperature on very cold days.

Are there any special precautions or red flags that I need to know about before I replace is such as what parts may need to be removed, any special handling of hoses etc?

What is the best way to refill the radiator?

Thanks in advance.

Jim