Security researchers have developed a home-made gadget called ‘CAN Hacking Tools (CHT) The device uses the Controller Area Network (CAN) ports that are built into cars for computer-system checks, and draws power from the car’s electrical system. Injecting malicious code to CAN ports allows an attacker to send wireless commands remotely from a computer. Once hackers take hold of this network they can control lights, locks, steering and even brakes. They have already tested their CHT device on four different vehicles and successfully did tricks.
Source: https://thehackernews.com/2014/02/hacking-car-remotely-with-20-iphone.html