I don't think you have business income unless you sell it right away. If you convert it to personal use, it becomes personal property.
Because you used section 179, this may trigger an immediate recapture. It's easier to explain with a simpler example. Suppose you bought the car in 2020, claimed section 179, and used it 100% for business. If you convert it to personal use in 2022, you have 3 years of deprecation you have to recapture (pay tax on) because the car is 5 year property and you are only entitled to 2 years of depreciation. That recapture is taxed on your 2022 business tax return (schedule C or other, depending on the type of business).
Because your section 179 claim was 5 years ago, but the vehicle was used less than 100% for business (I think that is implied in your question even though you didn't state it), those facts are too complicated for me to comment on the implications. Someone else will have to advise on how to calculate this. But you may have depreciation to recapture immediately. If you don't have to recapture any depreciation, then your cost basis going forward in your personal vehicle is zero.
Then later, when you sell the car, it is a personal sale only. Your basis in the car is the adjusted basis after any recapture. If you sell the car for more than your basis, you have a personal long term capital gain. I don't know what you mean by "accrued capital losses." You have to realize the loss by selling a capital investment at a loss, and it has to be a personal investment not a business one, since this would be a sale of a personal vehicle at that point. But if you have an investment you can sell at a loss, you can offset the gain on the sale of the vehicle.
@Hal_Al or @rjs might be able to help with the section 179 recapture.
