On the Car & truck worksheet, how do i find the Special Depreciation Allowance and AMT Special Depreciation Allowance

I am trying to file my taxes, but I keep getting an error saying that I must fill in 36i (Special Depreciation Allowance) and 36j (AMT Special Depreciation Allowance) on Schedule C: Car & Truck Expense Worksheet. The car was put into service in 2015 and is still in use today. I'm using the actual expenses method (which I have from the beginning) and on last year's taxes (through Turbo Tax) the boxes for these 2 items were left blank.  BTW, I'm in Texas. Please, please let me know what to do to find out what should be entered there and if it is indeed supposed to be blank--how do I correct the error I'm getting from TurboTax? Help is GREATLY appreciated