Temperature reading is off

I have my 2 carbons connected to a totalscan transducer that is 5 degrees off. Is there a way to reset it?

Are you sure one of the units is not reading another sensor on the boat? You can check both units one at a time by pressing PAGES - SETTINGS - NETWORK - DATA SOURCES, then select third category from the top and select Sonar, Wtr Temp.
I will send you a PM with phone number if you want to talk while you check this area.