Coolant Temperature not Logging

[Salad 419]

Sorry for this ridiculous post, I tried searching, but the search function would not work. When I log, My coolant temp is at -74.2F, but my temp gauge reads fine. Which of the two sensors on the Thermostat housing read the coolant temp that the logger sees? How do I correct this so the ECU sees the correct temp?

Thanks, Salad

 

[Jazzie6044]

It should be the smaller one on the bottom