Key Guard prevents thieves from starting your car with stolen keys. Key Guard is an electronic module that intergrates with a car's electrical sysem to prevent unauthorised use.It is controlled via an encrypted remote control keypad. Key Guard requires you to enter a 4-digit PIN number before the car engine will start.. You can enter you 4-digit PIN before or after you have unlocked your vehicle .You can personalise and change you PIN number as many times as you wish. Key Guard uses anti-scan technology, so a thief cannot electronically grab your code