I'm going to assume you have temp on your transducer at the bow. I'm also going to assume you've selected the correct transducer in the "installation" section under Settings/Sonar.
In Settings, under Networking, then Data Sources. Click the sonar that you have connected to that unit. Make sure it's set to LOCAL, over to the right on that same line as the check box is a triangle icon, click it and change it to local. Make sure there's a check mark in the temp "source" that you want to to read from.
Hope this helps.
Notice in my pic it's on depth... But the line above is for temp...