1992 300e coolant temp sensor
 

I have read about the 2 pin sensors and how to check but my car has a four pin sensor. How do I check this version? Can I check all points to ground or are there specific resistances available from pin to pin?

The pins are checked through the sensor for resistance. They are checked "across" the pins, like in an "X" pattern. The two resistances should be close to equal. I'm sorry I don't have the resistances memorized for a given temp setting, usually they will be upwards of 1000 ohms resistance, but again it varies according to temp.
Gilly