How to Add, Change, and Reprogram a Mazda 3 Spare Key

Whether you dropped your key fob on the floor or it has stopped working, it's best to have an extra key available. This article will cover everything you should be aware of when adding, changing, and changing the programming of your Mazda 3 key fobs.

Note: Some keys require programming by an experienced locksmith, whereas others don't. Make sure to use genuine Mazda replacements for your key fob.

How to add an additional key

You can also add an additional key in case you don't have a spare key, or when you accidentally damage your existing one. To accomplish this, you'll need an incredibly small screwdriver, a flathead screwdriver, and a new CR2025 battery. Once you've got these items you can remove the key fob and change the battery. First find the button that allows you to release the key. It's located on the underside of the metal portion and is easy to find. When you press the button, the cover should fall off right away. Then, insert the head of the screwdriver into the notch or space at the top of the metal component and pull it off.

Once the auxiliary key has been removed, insert the new or spare key into the slot. Set the ignition ON and wait for about five seconds, then turn it to OFF. This will register the new key's information to the system, allowing it to start your car in the future.


It's important to keep in mind that you can only program up to three keys on your Mazda 3. The final thing you want is to have more than two functioning key fobs, and not be capable of getting your vehicle started. This is a safety precaution designed to prevent unauthorised users, such as valet drivers from activating your key and thereby starting your car.

How do you reprogram a spare key

It's a smart idea be aware of how to reprogram an extra key in the event that your original key becomes lost or stolen. This will prevent unauthorized people from opening your car or taking it. This method should work on any Mazda but you'll need two keys working to begin the process of reprogramming. If you don't have two working keys, you should take your Mazda to the dealer to get this completed.

Begin by getting into your driver's seat and closing the door, except for the one that's open. Place the first working key in the slot, and then turn the ignition to the ON position. Take five seconds before removing the key. Repeat the process with the second key.

After you finish programming your new key you should have three keys that will allow you to start your car in the future. Check each key to make sure they're working correctly before placing them away.

You should think about purchasing a spare Mazda 3 remote, especially in cases where your car is prone to issues. You can purchase one online or at your local auto store, but be sure to read the reviews before buying so that you can avoid purchasing an item that isn't compatible with your car.

How to change the Battery on a spare key

It's depressing to find out that your key fob is dead and you're not able to unlock your car. It's easy to replace the battery yourself and save money at the dealership.

The first step is to press the auxiliary button on the back of the key fob. This will take out the metal key that is used as an auxiliary key, and expose two slots on the sides of the case. The flathead should be inserted into one of these slots and then gently push the two halves apart. When the battery is completely exposed, take it out and place it in a safe place in a place where you will not forget it.

Before you begin, make sure that you have a new replacement battery. These batteries can be purchased at any retailer that sells batteries or from a Mazda dealer in Winter Garden. The correct type of battery is essential to ensure that your keyfob works properly.

Then, put the new battery in place and replace the cap of the battery. Be careful not to scratch the rubber ring on which the battery rests. Then press the two halves of the key fob until you hear an audible click.

How do you reset the Keyless Entry System

The key fob in your Mazda 3 is not only an extra convenience, but also an important security feature. mazda 3 key replacement won't start if your key is lost or stolen, even if you've got an extra fob. This is because the key fob needs to be reprogrammed at the dealership to work properly. This can be an expensive and stressful experience therefore it's a great idea to understand how to reset the system yourself.

Remove the battery from the system for 15 minutes. This will clear any residual electricity from the on-board computer. Next, disconnect both the LF-ECU and demand switch connectors. Check continuity between the following terminals.

To program an entirely new key or spare, insert it into the slot and turn the ignition to ON. Leave the key in for about five seconds and then turn off. The key information is now added to the vehicle's computer and the new fob can start your vehicle. You can program as many fobs as you desire however only one must be used at a particular time. This will stop unauthorised people from copying the key and getting ahold of your vehicle. You can purchase a new key fob online, but you'll still have to visit an expert locksmith or dealer to have it cut and programmed.