Why Chevy Impala Won’t Start Security System [Reasons + Solutions]

The most common reasons behind Chevy impala won’t start security system are a bad ignition switch, security system failure, and battery issues.

Keep reading this article to find out how you can fix these issues. You’ll also learn how to turn off anti-theft on Chevy Impala here. Let’s dive in!

chevy impala won't start security system

Why Chevy Impala Won’t Start Security System [Reasons + Solutions]

If you’re wondering why my chevy impala won’t start, you’ll find the answer in this section. Here is the list of the common reasons why the Chevy Impala won’t start because of the security system:

Note: You can also read how to bypass anti theft system Chevy Cavalier.

1. Bad Ignition Switch

The ignition switch deals with the BCM or the Body Control Module of the car. A bad ignition switch sends the wrong signal to the BCM and can cause the security light to come on.

Sometimes the ignition switch gets damaged when a piece of the broken key stays inside it. That’s why the Impala security car won’t start when you turn on the key. There are both temporary and permanent solutions to this problem.


For a temporary fix, you can open up the dashboard door and locate the BCM fuse. It’ll most likely be a 10 amp fuse. Take it out for a few seconds and put it back in. Start the car again.

The security light will still be on and the car will crank. You may have to try it more than once for this temporary fix to work. While doing it is okay once or twice, you don’t want to do it all the time.

For a permanent fix, you’d have to replace the ignition switch. It’s not too expensive to replace the ignition switch. Replacing the ignition switch will take care of your problem in the long run, especially if doing the temporary fix every now and then becomes annoying for you.

2. Security System Failure

Because of glitches in the security system, sometimes it forgets the “key” and causes the security light to flash and keeps the car from turning on. If that’s the issue, you’d have to reprogram the key.


Instead of turning the key over like you would when you start a car, don’t turn it all the way. Keep the key in that position for about 10 minutes. What this does is that it allows the security system to relearn the key.

Once the ten-minute wait is over, the security light should stop flashing. Pull the key out and try to start the engine once again. If the engine starts, your problem is solved.

3. Battery Issues

When the Chevy Impala runs out of battery, it can trigger the theft-deterrent system in the car. If there are also other battery issues like low battery, the battery discharging itself, or the battery dies, it can also cause this problem.


You’d have to replace the battery of the car if it has been damaged and disconnects or discharges automatically. Make sure that the battery you’re using is in good condition before you start the car.

2003 Chevy Impala Won’t Start Security Light On Fix

How do you reset the service theft deterrent system on a Chevy Impala? You’ll learn how to do a 2003 Chevy Impala theft deterrent system reset in this section.

This car uses a pass lock system and if there are issues with the system, the engine won’t crank or start. Follow these steps to reset the pass lock system on a 2003 Chevy:

  • Put the key in the ignition and turn it into the “On” position.
  • The security light will be blinking.
  • Press the radio display button for a few seconds.
  • It’ll bring up the settings menu for the pass lock.
  • With the seek button, scroll to the option that says “Orig. Set”.
  • The “Orig. Set” button refers to Original Settings.
  • Press the next button once you get there.
  • The “Set All” option will appear next.
  • Press the display button and the system will start to reset.
  • Scroll to the exit menu using the seek button.
  • Take the key out of the ignition and wait for ten minutes.

After waiting for 10 mins, you’ll see that the red light on the radio control panel starts to blink. That means the system has been reset. The security light will also stop blinking once you’ve successfully reset the pass lock system.

How To Bypass The Chevy Impala Theft Deterrent System On A Chevy Impala 2004?

Bypassing the Chevy 2004 can act as a temporary fix if you don’t have the resources to fix the underlying issues. You may have to do this fix 5-6 times a year. Follow these steps to bypass the security system:

  • Turn the key to the “On” position.
  • Wait for at least ten minutes.
  • Take it to the “Off” position.
  • Wait for at least ten seconds.
  • Take out the key.
  • Turn the key back on and start the car.

Your security light should stop flashing. Be patient while doing it and make sure that you wait the full ten minutes. Otherwise, you’ll have to start the process from scratch again.


How do you know when the security light has been reset?

The security light will stop blinking and it’ll be steady or disappear completely when the theft deterrent system has been reset.

Will disconnecting the battery reset the security light?

Disconnecting and reconnecting the battery can reset the security light in some cases. You can always poop the hood, disconnect the battery for five to ten minutes, put it back in, and see if it works.

Can a door lock cylinder turn on the theft-deterrent system?

If the door lock cylinder and the door handles are damaged, it can turn on the theft-deterrent system in your Chevy Impala.

Is it normal for the security light to stay on when you start the car?

If the security light is on steadily, that’s not an issue. But if it keeps flashing or blinking, you won’t be able to start your car unless you bypass or reset the pass lock system in your car.


Now you know the reasons why the Chevy Impala won’t start security system and how you can fix it.

If doing the permanent fix can be troublesome for you, reset the theft deterrent system to get your car moving. Leave a comment below if you have any questions about Chevy Impala security systems.

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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