Auto loan being charged off

I have an auto loan that is being charged off. The principal balance of the loan has been paid off for about a year. I have been paying insurance money that the bank purchased about 2 years into the loan because I failed to show proof of full coverage. I have fallen on difficult times due to my wife losing her job, and have been unable to make the payments. The accout is about 6 months past due. My question is can the repossess the vehicle even though the principal balance has been paid, and what happens when an account is charged off.