Recently my car has been overheating on the highway. I will get going about 65 or 70 mph for a few minutes and the temperature gauge will slowly tick up from the middle all the way to the H. My car will then start beeping and saying engine idle please shut off engine. I will then pull over and shut off the car for 5 mins and then return driving and the temperature will slowly tick back to the middle, and this will keep going on if I am going over 60 or so. I took it somewhere and they think it is my temperature sensor, they said they dont think it is really getting that hot. I went and bought a new sensor so now my question is, Where is the temperature sensor located in the 1999 Cadillac Seville SLS?