I have been searching for several weeks trying to find the oil temp that the fan is supposed to come on on my 98 400. After finally finding a module that actually works, i can finally answer that question. Using an oil fryer thermometer in the dipstick hole it is right at 215 degrees fahrenheit, using an infrared thermometer at the oil filter cap and the case right above the sensor it was reading about 230. I am guessing that is picking up heat from the cylinder dissipating through the aluminum case. Hope this helps a bunch of people since it seemed to me a lot of people were asking this question but no one had exact numbers.