Vehicles are equipped with a wide variety of symbols meant to draw the driver’s attention to various functions. Since these signs vanish when the vehicle moves, they usually aren’t anything to worry about. These symbols may indicate a potentially serious problem, so it’s important that you pay attention to them and learn what they mean.
As soon as the car and lock icon appears, the anti-theft features of the vehicle have been activated, even though it could feel like you’ve lost access to your vehicle. It’s just a safety measure automakers take to make their products less prone to theft.
In this guide, I’ll explain in more detail what the car with a lock symbol means, the symptoms of a failing immobilizer, and how to troubleshoot the issue.
Car With Lock Symbol Meaning
The technical term for the symbol that looks like a car with a lock is “immobilizer.” This is a warning light that flashes on your dashboard to inform the driver that the car will not turn on.
This light should come on for a few seconds whenever you turn the key in the ignition, indicating that you have used the correct key to start the engine. Turning the correct key sends electrical signals to the car, telling it to shut off the anti-theft system.
On the other hand, when the key’s code isn’t recognized by the computer, the indicator light will blink rapidly, preventing the user from turning on the engine until you have used the correct key.
So, what about cars with keyless start buttons? The immobilizer light will still flash on and off. The light will remain off when the valid key is within detection range. Otherwise, it will continue flashing until the sensors can locate the correct key or when you have recharged or replaced the car’s battery.
The immobilizer indicator works in a standard fashion across makes and models, but for details on your vehicle’s setup, please consult the owner’s manual.
What Causes the Immobilizer Light to Turn on?
When the immobilizer light turns on and off, that means the whole system is ready to go. Your key’s code has been registered, and you can turn the engine on before letting it warm up and driving away.
But what can cause the immobilizer light to flash continuously? Here are a few common causes.
1. The immobilizer is doing what it’s supposed to
Best-case scenario (or worst-case, depending on whether you’re a car thief or are trying to “borrow” your parent’s car for the night), the flashing immobilizer light means that it’s working as intended. It prevents an unauthorized user with an invalid key from starting the engine and driving off.
2. Low car battery
If your car’s battery is running out of power, it can cause malfunctions throughout the vehicle’s entire electrical system, which includes security measures like the immobilizer. Low battery power may cause the immobilizer to flash regardless of whether you have the correct key or not. This is usually a problem for vehicle owners with keyless start buttons.
3. The key is out of range
In some cases, the immobilizer light will turn on and remain on when the key fob is out of a specific range. This is due to sensors that continuously check for the key fob, even when the emergency key is not used to start the engine. The sad reality is that in most cases, your car will merely make beeping noises when the key is out of range, which allows unauthorized users to force their way into your car, force the engine to start and drive off.
4. Bad key
A “bad” key doesn’t necessarily mean fake. In fact, you could be using the key provided to you when you first purchased your vehicle, but if it’s banged up and in rough condition, your vehicle’s immobilizer system may register it as a bad key and prevent you from starting the engine.
5. Forced entry
Modern vehicles have multiple anti-theft measures in place, including automatic locking doors. Usually, this locking system is tied to the immobilizer, so even if someone manages to break into the car by smashing the windows, the immobilizer will kick in and prevent them from hotwiring the vehicle and driving away.
Basic Troubleshooting Tips
Assuming you’re using the correct keys and are not trying to start the car outside of curfew hours (a feature found in the Subaru STARLINK system), here are a few things you can try to troubleshoot a problematic immobilizer:
Disconnect the car battery
Sometimes, disconnecting the car battery and letting it rest for a few minutes can reset the immobilizer system. The longer you disconnect the battery, the more power will drain from your vehicle’s electrical systems, leading to a “full reboot.”
- Enter the vehicle.
- Pull the hood latch.
- Lift the hood and keep it up using the hood prop rod.
- Disconnect the negative terminal.
- Disconnect the positive terminal.
- Wait for 5 to 10 minutes.
- Reconnect the positive and negative terminals.
- Try testing the ignition.
If disconnecting the car battery doesn’t work on the first attempt, you can try disconnecting the battery for 30 to 60 minutes to see whether draining the power resolves the problem.
Use another set of keys
When you first purchased your brand-new vehicle, you should have received 2 fobs and emergency keys. Try setting your go-to key fob aside and use the emergency one to see if that resolves the problem.
Contact your dealer
In extreme cases, you may have no choice but to rely on the help of professional mechanics. Ideally, you should contact the authorized dealer where you first purchased your car to see what they can do. If your car is still under warranty, you usually won’t have to spend a dime.
Contact a locksmith
Professional locksmiths may have the necessary tools to create a brand-new key for you, a microchip, and all. They may ask to check for proof that you are the car’s owner to determine whether or not to make a set of new keys for your vehicle.