I drive an older make and model of car and occasionally I have some troubles. One day I was going over to visit my sister and I parked in her driveway. As I was about to leave my car would not start. It was totally dead. My brother in law happened to be in the vicinity and he brought out a handy little tool that he called an automotive diagnostic tool and he proceeded to try and tell me what was wrong with the car. He is by no means a mechanic but he said that this little automotive diagnostic tool could help to narrow down what was wrong. I have heard my mechanic talk about using an automotive diagnostic tool on vehicles and it helps them decide what kinds of things may need repairs done. In the end the automotive diagnostic tool helped my brother in law decide that it was a battery problem and he helped me remedy the problem. I guess the automotive diagnostic tool he used did come in handy that day because I was on my way before very long.