OK, I have swapped that temp sensor between my two cars and deduced that the sensor is not the problem.

Could this be a ground connection problem?

Is there a document anywhere that shows all the geound connections thoughout the car? Seems like I've seen one somewhere.

The fact is though, that 4-pin connector does not use a ground connection and the temp sensor is isolated...really two identical temp sensors in one.

So, all things considered, it must be a wiring harness issue.

Agree?

__________________
2012 E350
2006 Callaway SC560