How to Fix the Car and Lock Light on Your Dashboard

• Try turning your key in the ignition. If the vehicle doesn’t start, leave the key in your ignition in the On position for 10 minutes to reset the system.
• Use your key or key fob to lock your vehicle’s doors. Unlock them after 10 minutes and try starting your vehicle.
• Disconnect your battery for about 10 minutes to reset the warning lights. If the light is still on, check and replace the fuse for the anti-theft system.

Car and Lock Symbol Meaning

Your vehicle is in anti-theft mode and may not start. When something triggers the anti-theft system, your vehicle uses an immobilizer to prevent thieves from driving away. While the car and lock symbol on your dash normally turns on if someone tries getting into your vehicle without the key, it may activate due to another faulty component. The anti-theft symbol on your vehicle may also look like the silhouette of a key inside of a car.

Fixing a Vehicle with a Lit Anti-Theft Light

Try turning your key in the ignition. Put your key in the ignition and turn it to the On position without starting the engine. Leave your key in the vehicle for about 10 minutes so the anti-theft system resets and detects your key. After that, the light will turn off and your vehicle will start. If that doesn’t work, check your key for any damage along the teeth or near the base. If you see nicks, dents, or damage, then replace your car keys at a local dealership or locksmith. If you have keyless ignition, use another one of the fixes listed below for your vehicle.

Unlock your doors with the key or fob. Roll all the windows up and close all the doors tightly. Use your key to manually lock all of the doors on your vehicle. Alternatively, press down on your key fob’s panic button for 5 seconds before pressing the lock button twice. Walk away for about 15 minutes before unlocking your vehicle again to check if the light reset. If the anti-theft light starts blinking when you try starting the engine, then the system hasn’t reset. If you have a spare key for your vehicle, try using that instead. If the spare key works, then the old key may be damaged. Replace the key fob battery if it isn’t working properly since your car may not be able to sense it. If it still doesn’t work, then get a replacement fob.

Disconnect your battery for 10 minutes to reset the light. Loosen the nuts on the battery cables to disconnect them from your battery. Touch the ends of the cables together to drain the rest of the current from your vehicle and reset the electrical system. After 10 minutes, reconnect your car battery and try starting your vehicle again to see if the car and lock light turned off. Disconnecting your battery also resets your vehicle’s clock and radio stations, so don’t forget to set them again. If your vehicle doesn’t turn on or start at all, then the battery may be completely dead. Check your car battery with a multimeter to ensure it has enough power.

Install a new fuse for the anti-theft system. Look for the fuse box on your vehicle, either behind a panel on the driver's side or under the hood. Check the back of the panel cover to locate the fuse for the anti-theft system. Test the fuse with a test light to see if it’s working properly. If the fuse is faulty, then replace it with a new one. Look for a fuse diagram in your vehicle’s manual if you don’t see one on the panel cover. Replacement fuses only cost around $20 USD, so replacing them is an affordable repair to try before spending money at the mechanic.

Replace the ignition cylinder if it’s damaged. The ignition cylinder is where you insert your key to start your vehicle. Inspect the cylinder for any scratches, pry marks, or separation between the components, which are signs someone attempted to start your vehicle without the key. Remove and replace the ignition to turn off the warning light. Replacing your ignition cylinder may require taking panels off of your steering column to access the parts. Alternatively, explain that there’s damage to your ignition cylinder to a mechanic to have it repaired for around $150–200 USD.

Contact a mechanic if none of the DIY fixes work. If you’re unable to solve the issue on your own, call your local mechanic and explain that the anti-theft system is activated on your vehicle. Let them know what you’ve already tried so they can check for problems with your electrical system or the actual immobilizer components in your vehicle.

Causes

Faulty key or fob If your key has nicks, scratches, or damage on any part of it, your vehicle may not recognize it. Similarly, if you’ve cracked the key fob or if it doesn’t have enough battery, your vehicle won’t be able to recognize it and may go into anti-theft mode to stay protected.

Dying battery When your battery doesn’t have enough power and goes dead, it may set off the immobilizer system in your vehicle and turn on the anti-theft light on your dash. If you jump-started your battery recently, the sudden surge of electricity may also set off the anti-theft system.

Old immobilizer system The immobilizer system usually only activates if someone tries to turn on your vehicle without the proper key, but an old, faulty system may have electrical issues. It may be as simple as a faulty fuse, or it may require more repairs to your vehicle's electrical system.

Damaged lock or ignition If someone attempts to steal your vehicle by breaking the lock or using a screwdriver in the ignition, your vehicle will recognize there’s a problem and immediately trigger the anti-theft system. Since your vehicle can’t tell the difference, any other damage to these parts could make the symbol light up too.