One of the most important indications drivers can use to keep track of their car’s performance is the dashboard lights.
These lights display status information about the components and systems that allow the vehicle to function. And when a light turns on, drivers know there may be a problem they must address.
The lock symbol warning light is one of the strangest symbols that drivers sometimes see on their dashboards. This dashboard symbol generally indicates that a security and anti-theft system has been activated.
While the symbol might seem alarming to drivers who first notice it, the illuminated lock symbol is generally straightforward for drivers to address.
What Does a Car With Lock Symbol Mean?
When the lock symbol is lit up on your vehicle’s dashboard, it indicates that the anti-theft system is activated.
This entails the activation of a factory-fitted immobilizer that prevents the engine from starting if the correct information isn’t received from the ignition key or fob.
Generally, the immobilizing system is extremely helpful to drivers. It ensures that malicious car thieves aren’t able to steal the car easily.
Unfortunately, the anti-theft system can activate for many inconvenient reasons and actively work against drivers. If you notice that your car’s anti theft mode is constantly starting, it may be a result of minor issues such as:
- A damaged lock on your car door
- A dead key fob battery
- A dead battery in your car
- A broken immobilizer chip in your key
There are many points in the authentication process where issues can occur. When you unlock your car with a smart key or fob, the microchip inside the fob sends a code to the Engine Control Unit (ECU).
If the authentication code that the immobilizer receives is correct, the car will unlock, and the engine will start.
If any of the components in the smart authentication system are broken, however, the car won’t be able to start properly. If the immobilizer or other authentication components in your car begin to fail, you may notice issues including:
- Your car alarm goes off constantly
- Your car won’t lock and unlock properly
- Your engine won’t start
- Your key won’t turn in the ignition
Common Causes of the Car with Lock Symbol
#1. Key Fob Battery Issues.
One of the most common reasons for seeing the key fob symbol on a car display is a weak or dead battery in your key fob.
Modern keyless entry systems rely on battery power to transmit signals to your vehicle. The key and vehicle communication can fail with low battery power, triggering the security warning.
Signs of a failing key fob battery include inconsistent remote locking/unlocking, needing to be closer to the vehicle for functions to work, or having to press buttons multiple times. The fix is relatively simple: replace the battery with a fresh one of the same type.
#2. Damaged or Faulty Key.
Physical damage to your key or internal transponder chip can prevent proper communication with your vehicle’s immobilizer system. This is especially common after dropping the key or exposing it to water.
Modern keys’ internal components are delicate electronic devices that can be affected by impact damage, water exposure, extreme temperatures, or electromagnetic interference.
If your valet keys work but your primary key doesn’t, this strongly indicates that the problem lies with the key itself rather than the vehicle’s security system.
#3. Immobilizer System Malfunction.
The electronic components of your vehicle’s immobilizer system can fail due to age, electrical issues, or software glitches.
This is particularly common in vehicles with high mileage or those exposed to extreme weather conditions. A malfunctioning immobilizer may fail to recognize even a perfectly valid key.
Common immobilizer system failures include damage to the antenna receiver, control module failures due to voltage spikes, software corruption, or communication errors between vehicle systems.
#4. Ignition Switch Problems.
The ignition switch plays a critical role in the authentication process. A worn or damaged ignition switch may prevent proper communication between your key and the immobilizer system, triggering the car security warning light.
Signs of ignition switch problems include difficulty turning the key, intermittent electrical issues, unexpected vehicle stalling, or the key getting stuck in the ignition cylinder.
#5. Electrical System Issues.
If you’re experiencing issues with your car’s immobilizer system, don’t hesitate to [contact us] for professional assistance.
A vehicle’s security system requires consistent, clean power to function correctly. Investigating the electrical system should be a priority if your vehicle exhibits other electrical symptoms besides the security warning light.
#6. ECU or Control Module Problems.
Occasionally, issues with the vehicle’s central computer (ECU) or the security system’s dedicated control module can trigger the warning light. This might be due to software corruption, hardware failure, or damage from previous repair attempts.
These complex issues often require dealer-level diagnostics or specialized repair shops with advanced scanning tools similar to those used by FCC application testers for vehicle compliance checking.
#7. Recent Battery Replacement or Electrical Work.
Sometimes, the car alarm symbol on the dashboard appears after a battery replacement or electrical system service. This occurs because the immobilizer system may need to reset or recalibrate after power interruption.
When a vehicle’s battery is disconnected, various systems may reset to default states or lose learned settings. Security systems, which are designed to detect tampering attempts, are susceptible to these changes.
How to fix Cars with a lock symbol
To fix a car with lock symbol, you want to replace the battery in your key fob and inspect the car locks. Then, you should try your spare key fob. If you see the same issue, you know there is an issue with the original key fob.
#1. Inspect Key Fob/Door Locks.
Considering the most likely cause of your problem is either the key fob or the lock, it’s important to begin the inspection here.
Check the key fob battery, as these only last a few years at a time. If you can’t use the key fob to unlock or lock the doors, it’s worth replacing the battery. Most batteries only cost around $5.
If the key fob doesn’t work after replacing the battery, it may be damaged. You need to have it replaced. The cost for a new key fob can vary based on what it’s used for.
If it doesn’t need to be reprogrammed by the dealer, you might only spend $50 online to get a new one.
However, the cost can quickly become more than $200 if the dealership is your only option. You may also need to program it to the immobilizer, which only a locksmith or the dealership can do.
Your next step is to look at the door locks. If the door locks are damaged, the anti-theft warning system could be triggered.
Finally, an inspection of the ignition cylinder must be examined. If someone tried to break in and mess with the ignition, it could be damaged.
This is what happens when a thief attempts to jam a screwdriver into the lock cylinder. Sadly, you will probably need to replace the ignition to fix this problem.
#2. Try Spare Key.
Take a look at your car key next. If it’s damaged, the system might think you are trying to break in. You can try a spare key in the lock to see if that fixes the problem. If so, you might need a new key.
Not all modern cars use a physical key anymore, so this step might be skippable. If you only use the key fob system and a proximity key, this step doesn’t apply to you.
#3. Replace Dead Battery.
If the battery isn’t charged fully, the same problems can occur. Start by unplugging the battery terminals to perform a reset and charge the car battery.
After ten minutes, you can reconnect the battery to see if that fixes the problem. However, doing this will also reset the electronics, including your clock and radio presets.
If that doesn’t fix the car with a lock symbol, it might be time to see if the battery is dying. If so, replace the battery to resolve the problem.
#4. Attempt to Start the Car.
The car probably won’t start while the car and lock symbol are on the dashboard. For this reason, you must first attempt to turn off the light before you can start it.
Put the key in the ignition and see if the light begins to flash. Once the car doesn’t start, you can switch the ignition back off and wait a few minutes. If the security system stops flashing, it has disabled itself, and you can try to start the vehicle once again.
#5. Use a Physical Key.
If you have a physical key that can be used on the doors, try this method to reset the system. Some key fobs contain a hidden key that can be pulled out for a time such as this.
Insert the key into the door and attempt to unlock it. Don’t open the door if it unlocks. Instead, leave the door unlocked for about a minute. During this minute, the security system should recognize that you are using the right key and disable it.
You can also attempt locking and unlocking the door several times. This method can cause a reset that disables the system.
#6. Check Fuse.
The car immobilizer uses a fuse to run the electrical connection. Fuses are not immune to damage, so there’s always the chance that it needs to be replaced.
Find the proper fuse to check by looking at the diagram in your service manual. You also need to make sure that the fuse is the same amperage as the one you are replacing.
#7. Call Locksmith/Mechanic.
If the above steps haven’t brought you to a resolution, it’s time to seek professional guidance. If the trouble seems to revolve around the lock or key, you might do better to reach out to a locksmith.
Otherwise, diagnostics should be performed by a qualified mechanic. If there’s a malfunction with the immobilizer itself, you may not be experienced enough to handle the repair.
What Is the Reason for the Pop-Up of the Car with the Lock Symbol?
Typically, your car’s key fob must be close enough for the transponder chip, which transmits a regulation to the vehicle’s immobilizer procedure, to accept it.
Regardless, compatible when the key is immediately sufficiently to communicate the code, the immobilizer procedure may be triggered, so the sunshine turns on, and the “car with lock” symbol pops up. This is usually due to the following:
#1. Low Battery.
When a car’s battery is melancholy, it abandons the recollection of the key. A low battery may provoke the immobilizer daybreak on the dashboard to come on.
Actually, if the key is immediately adequate, it still may not start because its code will not be recognized and seen as foreign to the car.
#2. Damaged Car Door Lock.
When the anti-theft procedure observes any compelled entry into your car, the dashboard lights depend on, the immobilizer boots in, and the appliance cannot be extended commencement. A broken car entrance lock can occasionally be the motivation.
As a consequence, the procedure may be incompetent in distinguishing between an attempted car stealing and a discontinuous car door lock.
So, you then terminate up with the symbol “car with lock.” While the immobilizer procedure may be a state-of-the-art protection characteristic, it is not a positively materialized procedure.
#3. Bad Key.
If your car contains a keyless ignition, you may not presently acknowledge it. If your key is damaged, your car’s immobilizer system may also be activated.
When this occurs, the anti-theft system intention is triggered presently. The key’s fragment can be shattered, stemming from connecting the appropriate code to the immobilizer procedure.
#4. Immobilizer Damage.
A damaged immobilizer may prevent the transponder key’s codes from being read. Inspect the circumstances of your immobilizer if the immobilizer sunshine on your dashboard is nevertheless on.
FAQs.
Q: Why is my car showing a car with a lock on it?
Your car can display a car with a lock on the dashboard for several reasons. For instance, it could be someone tries to break into your vehicle, the key fob battery is dead, the blown immobilizer fuse or the immobilizer is damaged. In any case, the light means the anti-theft security system has been triggered.
Q: How do I get my car out of anti-theft mode?
As explained earlier, several methods exist to remove the lock symbol on a car, depending on the leading cause.
However, here’s the most common way of getting out of anti-theft mode. First, insert the physical key and unlock the driver’s door. Then leave the key inside in the unlock position without opening the door for 30 to 45 seconds.
If that doesn’t fix the problem, repeatedly lock and unlock it with the physical key. If this method does not get rid of the anti-theft mode, scroll up and try the other methods listed above.
Q: How long does it take for the anti-theft system to reset?
This depends on the approach you choose and your vehicle model. For instance, if you decide to reset the car anti-theft system on your Honda car by unlocking and locking the driver’s door with a physical key, it’ll take around 10 minutes of driving to reset the anti-theft system. Other vehicles may take lesser or longer than that.
Q: What happens when your car goes into anti-theft mode?
If your car goes into the anti-theft mode for any reason, it’ll project a car with a lock symbol on the dashboard and prevent the car engine from starting.
This can happen for several reasons, but until you track and fix the leading cause, the vehicle will not start. Meanwhile, this can happen for no apparent reason, such as having a locked steering wheel. Therefore, you have to check every possible cause and rectify it.
Final Words
The anti-theft features in cars make it difficult to steal cars in today’s world. However, they can malfunction and keep you frustrated or, at least, make you think you have serious underlying problems that need your attention.
The system can act up due to lousy keys, dead key batteries, faulty door locks, etcetera. When the car triggers the anti-theft feature, the car won’t start until you deactivate it.
This article has explained car with a lock symbol how to fix, to help you resolve the issue and start your vehicle. Follow the above guidelines religiously to clear the security light and start your car.