There is a forms icon just below the top right of the Turbo Tax screen. If you're in the California state part of the program, you click on the forms icon and select form 3554 from there. Then select the option to delete it.
I'm no expert, but I didn't have to delete my CA return to get rid of form 3554. The fact that the form is spontaneously popping up during the checking process makes me suspect that this is a bug.
