Modern cars have multiple security measures in place to ensure that the correct key is being used to start the engine. Car keys are electronically coded specifically to work only with certain engines that have learned this code. Even if someone was able to copy the key and turn the ignition, the engine still would not start.
Without the correct key, it is very difficult to start the engine of most modern cars these days. Most vehicles have an ignition switch warning light to let you know of any problems occurring with the ignition.
What the ignition switch warning light means
Depending on the vehicle, this warning light could mean a few things. It could indicate an issue with the ignition switch or show that there is a problem with the key being used. An issue with the ignition switch is usually mechanical and it would prevent the key from turning. This may be caused by worn out tumblers, a worn out key, or if dirt and debris lodged in the mechanism prevents movement. You can try cleaning out the keyhole, but you may need to replace the switch and potentially even replace the key to fix the problem.
If this light comes on while you are driving, chances are the key can longer be verified. This is typically a computer glitch, and while rare, it can still happen. Since the key is no longer valid, it is likely that you will not be able to restart the engine once you have shut it off. Take the car immediately to an auto shop or service center where you can have the car relearn the key’s security code.
Is it safe to drive with the ignition switch warning light on?
In either situation, you should have the car checked out. While it is possible to do the key learning procedure without any special equipment, it typically requires two known, valid keys which could be difficult to gather, if you’re out and about. Any mechanical issues will also require cleaning or replacement of the ignition switch.
If you are having any troubles with your ignition switch, our certified technicians can help you diagnose any issues you may be experiencing.
This article originally appeared on YourMechanic.com as What Does the Ignition Switch Warning Light Mean? and was authored by Spencer Cates.