A key fob with remote locking/unlocking and push-button start. A key fob with push-button start and keyless entry that owners can leave in their purse or pocket for virtually all functions.

Learn how to choose and install a new Ford Fusion key fob battery to keep yours in perfect working order.

New key fobs must be programmed with codes that the vehicle has to read before it unlocks the door or allows starting the engine.

A push button start key fob is a button that allows drivers to start their engine by pressing it. That said, you won't be able to turn on your car if you don't apply your vehicle's brakes.

Push-button ignitions work via the fob, also known as a "smart key," which allows a driver to keep the device in a pocket, purse or other place when unlocking, locking and starting the vehicle.

When you need to find your key or key fob, you may not know which pocket it’s in. Also, you get so used to not using a key that you may forget to turn the vehicle off with the button.