I had a similar issue and it was answered by an Intuit employee as stated below. My issue was resolved by following these steps: Original answer by TurboTaxMichaelDC
What this means is that you have set the depreciation value to high in comparison to what the vehicle is worth. What you can do is:
1. Delete the vehicle and start over again
2. Add it back in with its original service date.
3. Calculate your estimated depreciation per year based on miles used for business
Also try these fixes:
Go back to the sale of vehicle and delete any numbers in the AMT section.
In Smart check, when the worksheet is displayed, right click on the field (Line 50 and/or Line 51). From the dropdown menu displayed, select "Override". You should then be able to enter any number that you want.
Depreciation assumes that assets used to generate business income will wear out, get used up, or become increasingly obsolete over a period of time. For taxation purposes, depreciation lets you deduct the "used up" portion of that asset's cost every year, until the entire cost is used up or the business no longer owns the asset. You cannot claim more in depreciation than the value of the item. In this case, your vehicle.
The prior AMT depreciation would be the same as the prior regular depreciation if the depreciation was calculated by using the standard mileage deduction.
It would also be the same if, when you depreciated the vehicle using the actual costs (fuel, tires, etc.). rather than the standard mileage, you chose a straight line depreciation method. (This is explained in the screens entitled "Let's Figure Out How to Deduct Your Vehicle Costs" and "Section 179 Deduction" which includes a link to on-demand tax guidance about the depreciation deductions you had used for your vehicle in the past).
If you don't remember, that's OK, use the defaults presented in TurboTax. If you've had the vehicle longer than 5 years, it would be fully depreciated under both the regular and AMT methods.
To get back to this in TurboTax:
· Under "Business Income and Expenses" select start/update next to Profit or Loss from Business
· Click "edit" on the Business Summary
Scroll down to business expenses section, and click update next to "Business Vehicle Expense"
Refer to IRS Publication 946, How to Depreciate Property if you require more detailed, in-depth information.