If you're looking to pick up a new key fob, or repair one, you might wonder how long programming it takes and whether or not you can do it yourself.

The key fob is your lifeline to your car, letting you unlock the doors and set off the alarm, at a minimum, but how can you tell if it needs a new battery?

Several car manufacturers require the use of special scan tools to reprogram their key fobs. Some license those tools out to locksmiths and auto repair shops.

Hyundai Sonata's Digital Key means you can leave the fob at home Unlock, start the engine and go, all from your smartphone.