Hi, how do we take advantage of the section 179 full deduction for a new vehicle used 100% for business? Thanks!

We are self-employed filing married jointly, using Turbotax Home and Business. We purchased a new cargo van over 6000 lbs (Ford Transit 250) in 2017. When we enter the new vehicle in the Business Vehicle Expense section, and choose the Actual Vehicle Expenses method we do not get the option to depreciate the full amount of $31,000.  If we enter the vehicle in the Business Assets section, we do see the section 179 option and can deduct the full amount. Should we enter the new vehicle under Business Vehicle Expense, Business Assets, or both? If we have to enter the new vehicle under Business Vehicle Expense only, how can we take advantage of the section 179 deduction? Thank you!