Mazda 3 Key Fob Replacement Mazda 3 owners may need to change the battery in their keyfob in time. This is an easy task that you can complete yourself. Find the small button on the back of your key fob. Press the button to remove the cover. Lost Keys Before the 1990s the 1990s, losing your car keys was a minor inconvenience. You could replace keys at any hardware store, locksmith store, or dealer and it was affordable to do this. Your car's top-of-the-line key fob can do much more than just lock and start your car. But that added convenience comes with a price - more expensive replacements. The key fob comes with an encryption chip that sends an unique code to the computer of the car to unlock and begin the. The key fob is capable of controlling various other features, including closing the windows if you're in a hot parking lot and summoning your car to allow you to turn around in a tight spot (a feature found on some Genesis GV60 and Hyundai Sonata sedans). Mazda's remote controls aren't nearly the price of other car makers'. With a little knowledge you can replace the battery on your key fob by yourself. You'll require a flathead screwdriver and an updated CR2025 to do this. Be sure to use the directional buttons and red button to unlock and lock the doors before changing the battery. If you're looking to save money on the cost of a Mazda 3 key fob replacement search for one on the internet that is OEM and does not require programming by a locksmith or dealer. eBay offers a variety of options, however, they might not be the same color as your existing key fob. Lockouts A driver who is locked out of their vehicle is one of the worst things that can occur. There are several tricks drivers can employ to gain entry into their car. First, they should call their local Mazda dealership or locksmith. This is a great option because it's likely to be cheaper and faster than calling a truck. The locksmith or dealer will require a key code from the database to create an additional key fob, which typically costs about $100. This is why it's important to save the code in a secure place. If you are stuck outside your car, the second thing you can do is search for an additional key located under the car's underside. The button is typically small and round that can be press. This will open the doors of the vehicle, allowing the owner to open them by hand. Another method to gain entry into the vehicle locked is by using the emergency override feature. This will allow the key fob's device to bypass the functions that are suspended by the theft-deterrent system. This will activate the alarm lights and sound to ensure that the doors, the lid for the fuel filler or liftgate have been shut. Transponder Chips If the key fob you have has a transponder chip embedded in the head of the key with the L shape, you'll need a locksmith or dealer to have it replaced. These chips come with a unique identification code which is used to open your vehicle. When you insert your key and then turn it to the ON position the antenna ring releases an explosion of radio frequency energy that will reach the transponder chip within the metal key. The chip responds with an encoded code that is sent to the antenna ring telling the car that it's a valid key. Most Mazdas utilize a transponder chip that is rolling code that changes its code every time you turn the key. This means that the key you're using will never work with your car until you have a second copy with the same exact code inside the ignition cylinder. It's possible to create your own replacement keys. If you're able find an actual key, you can insert it in your Mazda and set the ignition to ON. You can copy the data from the key to another key if it starts your Mazda. You could also try the eraser method on your key fob in order to erase the current code, if required. It is important to note that this method isn't certain to work as certain transponder chips that have been recycled might not be able to respond properly. Programming Losing your car keys is an expensive and time-consuming experience. Luckily, Mazda has made it easy to add a third key. You can do this with just a few steps and you will not need to pay the dealer for the service. If you have an extra car key, this is the ideal way to avoid paying for towing and dealer charges. First, you'll need to buy a new battery for the fob. You can buy one at an online retailer or a hardware store for about $10. You'll also require an open-ended screwdriver that is flat to open the fob. The screwdriver's head must fit inside a tiny slot or a space on the side of the fob. After you've removed the case and battery, you'll need to replace the old battery with a new one. Now you can program your new key fob. To do this, simply insert the first working key into the ignition and turn it on. For about five seconds, you should wait before turning the ignition off. Repeat the process using a second working key, and then your new (or spare) key. After you've completed this and your Mazda should be able to be started using the newly programmed keys. If not, there may be another problem with the key fob, or the vehicle.