I have been seaching for the temperature sensor location and have had no luck. The engine coolant sensor on the thermostat housing is all I have found - please help!

That is your engine temp sensor. It detects the temp of the coolant right before it goes through the thermostat. If you are having a problem also check the relay and fan motor. Good Luck.

is that the sensor that makes the fan turn on?

Yes, it is wired to a relay near the battery. From the relay you can follow the wires to the fan motor.

Usually, but not always, its the relay when the fan doesn't come on.

Yeah, that has been my experience as well.

I changed the relay and i changed the engine coolant sensor, but have had no luck locating the temperature sensor which the dealer assures me does exist on this car.
It overheats then cools down quickly then maintains normal temp until i shut car off and start it then it goes through the same cycle.
I am at a loss as to what the problem may be or where this "ghost" sensor is.

Haynes Manual in your future???

I have thhe haynes manual yet it doesnt show me the part that is listed. I am changing the ECM and see if that is the problem.

Thanks for your help!

Whoa, ECM I don't think that is going to help. If it does feel free to call me on it. I would change the temp sending unit first. That one you see by the thermostat. On some cars they use a single unit as a source for the gague and the fan.

Took it to the dealership, i have changed the sending unit at the thermostat and the relay, replaced the fan motor for shits and giggles, but no help. put it on the diagnostic machine and ecm is bad - changing it now only 128.00 so cheaper than buying new car.

Yeah, it is hard to argue with a computer that suggest a $128 repair. That isn't too bad. Good Luck. Probably better that direct wiring the fan.