Phone temperature too low

@itsserge most common is actually a failed sensor on the ribbon cable from the daughter board to the main board. Replace that first. If that does not work, then this could be an issue with the battery or the daughter board. You can replace those and see if that fixes the error. Most common is actually a failed sensor on the ribbon cable from the daughter board to the main board. Replace that first. Let us know what you find out.

Since iFixit does not yet have a guide for this, use something like this video

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!