front of the car by the air filter area. Several Z sites offer a relocation kit or you could just relocate it without the kit. I have seen a YouTube video showing this performed. Also try the search function on this website to locate additional information as I know there was a recall on the early PTUs and this was discussed previously. I personally relocated my PTU to keep it as far away from heat as possible. It is an easy fix. But specifically to answer your question, heat is detrimental to the PTU.