Still looking but leaning toward there is something from the personal data I have observed in my own vehicle and some of the FSM data. I can't say definitively either way though at this point. If it is there it isn't a standalone sensor and like I said before part of the valve body or that ECM. It wouldn't take much to integrate a temp sensor. With it being water cooled temps would often stay close together with normal driving. I even seen this on my GX...but start pulling heavy loads on hills, mountain passes or towing trailers and one should see temp gap noticeably widen.