When you see the car lock symbol on your dashboard, it means that the vehicle anti-theft system has been activated. This system is designed to prevent thieves from stealing your car by making sure that only authorised key fobs can start your car's engine. This system works by sending a signal through the key fob to your vehicle's computer. The computer then checks the signal to make sure that it is an authorised key fob. If it isn't, the car and lock symbol will turn on.
This warning symbol can also appear when there is a problem with the anti-theft code or the ignition key. The most common cause of this is a dead battery in the key fob, but it can also be caused by a faulty immobilizer, a bad door lock or attempted theft. It is important to remember that it is extremely difficult to bypass or override the immobilizer without the help of a professional, so it is best to leave this problem to a dealer or locksmith.
If you have a car with lock symbol on your dashboard and it won't start, try locking the doors manually and then disconnecting the battery for 10 minutes. This should reset the anti-theft warning light and allow you to start your car. If you are still having trouble, it may be time to have a mechanic check out the anti-theft system in your car. They will be able to recommend the right solution for your specific situation.