What Does The Car Lock Symbol Mean?

Many car owners don’t know what every symbol on their dashboard means. If you’re wondering, “What does the car lock symbol mean,” then you’ve noticed a new indicator light resembling a key, lock, or similar item.

While it may seem threatening or strange, the car lock symbol simply indicates that you’ve activated your car’s anti-theft system. Like other dashboard symbols, the car lock indicator light may stay lit until you deactivate it.

You may also have trouble using your car normally. Learn more about the car lock symbol and what to do if it flashes or turns on.

Car Lock Meaning: Why Your Car Has A Pre-Installed Anti-Theft System

Car owners may not realize they have a built-in anti-theft system before driving their vehicles. Most car manufacturers install an anti-theft system in each vehicle as a deterrent to car thieves. When the anti-theft light comes on, your car locks itself against potential attackers.

Besides auto-locking, your car may have an immobilizer installed that keeps your engine from starting. While a great way to stop thieves from stealing a car, when the immobilizer activates against its daily driver, it can cause frustration and confusion.

Why Did The Car Lock Symbol Turn On?

Whether you use a key or have a keyless ignition, your car lock symbol can activate. Many things may cause your car lock indicator to turn on.

The car lock symbol could mean one of the following:

Dead Or Dying Car Battery

If you have a dead battery or if you have a failing car battery, your car lock indicator light may come on. Without a good battery, your car can forget your key or key fob and treat your attempted entry as a car theft.

Besides locking your doors, your car engine may deactivate, causing you to lose control of your vehicle completely.

Broken Key Or Bad Key Chip

Broken, misshapen keys may activate your vehicle’s anti-theft system. Keyless ignitions rely on a good key fob chip, so if your chip has recently failed or developed a fault, your car won’t recognize the code. In both cases, you may accidentally activate your car lock symbol.

Car Door Lock Damage

Attempting to force your way into your car can trigger the anti-theft system. While most vehicle owners won’t try to break into their own cars, cold weather may freeze a door shut, or something may prevent a door from opening properly. Thus, when you try to open your door forcibly, the immobilization system turns on.

Recent Engine Work

When a mechanic works on your engine, your vehicle may not register the changes properly. Instead of understanding that you had work done on your car, the anti-theft system may activate itself. However, if recent engine work causes your immobilization system to kick off, you may also notice other problems with your engine and battery.

Unusual Activity In The Vehicle

Car thieves might do any number of things to break into a vehicle, making it easy for the immobilizer system to recognize unusual behavior and lock the car down.

However, some of these activities may happen during regular use of the vehicle, such as accidentally using the wrong key, moving around inside the car, and attempting to force open your hood or trunk.

How To Fix Lock Symbol

If you’re locked out of your vehicle or dealing with a dead engine while staring at a new indicator light and wondering, “What does car lock symbol mean,” you can try any of these four methods to fix the problem. Try each technique on its own at least twice before moving on to the next to make sure that you’ve thoroughly attempted each one.

1. Hard Reset The Battery

A quick and easy way to reset the immobilizer system involves a hard battery reset. Pop your hood and remove the battery terminal from the positive or negative side. Wait for at least five minutes, then reconnect the battery and try to turn your car on.

2. Charge Your Battery

You might see your car lock symbol turn on if you have a low car battery. Use another vehicle or a car battery charger to juice up your battery before trying to turn your engine over. Wait at least ten minutes to ensure that your battery has enough time to charge completely.

3. Check Your Key Fob

A malfunctioning or broken key fob can trigger your anti-theft system. You may need to replace your key fob or put a new battery in it before trying to activate your vehicle again. If you feel that the problem lies with your key fob, move on to method four.

4. Use A Physical Key

Even if you use keyless entry and ignition, many vehicles come with at least one physical key. Unlock your car door with the physical key, but don’t open it. Instead, let the key settle in the unlock position for about a minute.

Many cars will recognize that you have a legitimate key and release the immobilization system. You may need to try this method multiple times before your vehicle recognizes the key.

What Happens If The Car Refuses To Start?

If your vehicle’s car lock symbol stays on and your vehicle’s engine refuses to start, you may need to contact your dealer. Sometimes, manufacturers share online tips on specific models and how to disable the immobilization system, or you may find videos that show how others have fixed their cars.

You can also consult your vehicle’s manual to see if the manufacturer included the necessary steps for disabling your anti-theft system. In the worst-case scenario, you’ll need to have your car towed to your local mechanic so they can disable the system for you.


When drivers see an unusual indicator light turn on, it’s normal to feel confused and worried. However, if you’re searching for “What does car lock symbol mean,” you can use the guide above to attempt resetting your anti-theft system yourself.


Garry is the happy owner of a funky 2018 Nissan Juke Ti-S AWD. After growing up around his family’s mechanics shop, he is passionate about bringing budget-friendly car care to every driver. Garry has a business degree and is a car enthusiast.