Car With Lock Symbol Light On? (5 Causes and Potential Fixes) (2024)

Ever spotted what looks like a ‘car with lock symbol’ lit up on your dash and now your car won’t start? You’re definitely not alone. But what exactly is the problem?

In this article, we’ll break down 5 common reasons you might be seeing this symbol and offer some potential fixes you can try before heading to the mechanic.

What Does the Car With Lock Symbol Mean?

There are several variants of lock symbols you might see on the dashboard. Typically the light is related to theimmobilizer.

Before immobilizers, vehicles were quite prone to being stolen if someone wanted your car. This could happen when the thief hotwires your car. Sometimes simply sticking a screwdriver in the ignition would do the trick. The immobilizer system is designed to prevent both of these scenarios.

Reasons You’re Seeing the Car With Lock Symbol

Not all causes of the car with lock symbol are bad. For the ones that are, we’ve included some potential fixes you can try yourself before bringing your vehicle into the shop.

1) You’ve Locked the Car

When you lock your vehicle, you will see a little red light that blinks intermittently. The light looks like a car with a padlock, or a car with a key. This light indicates that the vehicle is locked and the security system is activated. In this state it should not be possible to start the vehicle without a valid key.

If you were to unlock the vehicle from the inside while this light is blinking, it is likely that your car alarm will go off. It’s important to remember that you may set off your car alarm if you have the window rolled down, lock the vehicle from the outside, and then unlock the vehicle from the inside by reaching through the window.

2) Problem With the Immobilizer

The immobilizer system consists of a computer, the ignition or lock cylinder, the key(s), and the transponder. If any of these systems malfunction, you may see a warning light such as “key not detected”, a car and lock symbol, or a car with a key icon. The warning light is typically amber or red in color.

If you have aproblem with the immobilizer system, odds are really good that you will not be able to start the vehicle, even if the vehicle is otherwise functioning perfectly. This is a safeguard that keeps the vehicle from being stolen when someone who is unauthorized tries to start the car.

3) Key Not Detected

A key that is not detected by the car will be unable to start the vehicle. The most common reason a key is not detected is because the battery is low. Try replacing the battery in your key fob and see if this resolves the problem. Key fob batteries typically last about a year, but may last even longer in some cases.

Some key fobs have a spare physical key in case your battery dies. Some keys are designed so that you can touch the back or side of the key to the ignition button to start the vehicle. This is a feature offered on some push button start models.

Check online for an example of how to start your car with a dead key battery, because the process will look different for each make and model. YouTube is a great source for these types of videos.

4) Problem With the Ignition

The transponder may be placed inside the ignition in some vehicles. If you have a bad ignition, your key might not be detected properly, even if you have a fresh battery in the key fob.

On vehicles that come with an old school key that you have to turn in a lock cylinder, the mechanical components inside the ignition may wear out over time. This is more probable if your key is old and worn out, or you have a heavy keychain hanging off of the ignition while you drive.

If yourkey is stuck in the ignition, try jiggling the key and the steering wheel at the same time to see if this allows you to turn the key in the ignition. If this trick works, start thinking about replacing your ignition before the problem gets worse.

5) Key Is Not Programmed

If you have recently purchased a new key, that key will not work with your vehicle until it has been programmed.

Each key needs to be programmed to the vehicle in order to start that vehicle, and this is not a process that is easy for the consumer to do themselves. A specialized professional scan tool may come with the features needed to reprogram keys, butinexpensive consumer scan toolsdo not typically have this feature.