Car With Lock Symbol: Meaning & How to Fix

Tim Miller
Car With Lock Symbol


The anti-theft system malfunctions.

Car With Lock Symbol


  • Key Related Issues
  • Faulty Immobilizer Components



Easy to fix


What Does a Car With Lock Symbol Mean?

The car with a lock symbol called the security indicator light indicates the activation of your vehicle’s immobilizer or anti-theft system.

The symbol, behavior, and meaning can vary between different vehicles. Thus, refer to the owner’s manual or our Dash Lights Lookup for specific information on your vehicle’s system.

Generally, the concept is the same. When you turn the ignition to the “ON” position, the immobilizer system performs a self-check, triggering the security indicator light to illuminate for a few seconds. If the system functions well, the light turns off.

However, if the light stays on and the engine fails to start, there could be a problem with the anti-theft system.

Note that in some cases, the light might blink even when the engine is running.

Let’s find out the possible causes in the next part. 

Why Does the Car With Lock Symbol Come on?

Key Related Issues (Most Common Cause)

The key or key fob contains a transponder chip to communicate with the immobilizer system. When you start the car, the immobilizer system verifies the code transmitted from the chip. If the code doesn’t match the stored data, the system will shut off the engine and activate the security indicator light. 

Some possible key problems that disrupt communication with the immobilizer system include the following:

  • Damaged transponder chip
  • Low or dead key fob battery
  • Unprogrammed key

Faulty Immobilizer Components

This can be due to issues with the control module, antenna, or wiring. In such cases, professional diagnostics and repairs are necessary to resolve the problem.

What to Do if the Car With Lock Symbol Comes on

Here are some steps you can take when encountering this situation:

Step 1: Restart the engine

When you see a car with lock symbol on your dashboard and the car fails to start, switch the ignition off, and try restarting the engine. Temporary glitches or communication errors can sometimes trigger the light.

Note: Before restarting, ensure the key is programmed and within the operational range. Also, keep metallic objects or additional coded keys away from the main key.

Step 2: Visually inspect the key

If the key has any signs of damage, replace it.

When buying a new car, you typically receive two sets of key fobs. This allows you to have a spare key fob in case one is lost or damaged.

You can also choose to have additional key fobs, and of course, they need programming. Check the service information to know the key programming procedure, as some vehicles may require a specific sequence of actions like turning the ignition on and off or pressing the pedal to learn new key fobs. Some more sophisticated systems may require a key programmer.

For hassle-free key programming, consider investing in a key programmer tool, such as the XTOOL InPlus IP616. The tool simplifies the process by providing step-by-step instructions and compatibility with various vehicle models, ensuring you can easily add or replace key fobs as needed.

Step 3: Check the key fob battery

A key fob often has a built-in LED indicator light. Press any button on the key fob, and if the LED light appears dim, it is a sign that the battery may be weak or depleted.

You can use a TPMS tool to test the key fob’s operation. As key fobs and TPMS sensors use the same frequencies, most TPMS tools often have a built-in function for this purpose. 

If the key fob has a weak signal, replace the battery and reprogram the key fob.

Step 4: Perform further diagnostics and repair

If the above steps do not resolve the issue, it’s possible that the immobilizer has trouble with the antenna, control module, or wiring. As the system is quite complex, you should seek assistance from a qualified automotive technician or dealership. They have the expertise and diagnostic tools to inspect and repair immobilizer system problems accurately.

What’s Next?

A car with lock symbol indicates the activation status or any potential issues of the immobilizer system. Understanding its meanings and taking necessary actions ensures proper immobilizer function and enhances overall vehicle security.

We appreciate your thoughts! Please leave a comment with any questions, experiences, or insights you have regarding the security indicator light.

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Information sourced from the owner's manual.