How to Replace a Dead Battery in the Mazda3 Key Fob?
2 Answers
Place the back of the smart key near the start button and press it. Vehicles with push-button start have a sensing area inside; usually, placing the smart key near this area will still allow the car to start. If the Mazda3 key fob battery is dead, it should be replaced as soon as possible. The method for replacing the battery in the Mazda3 key fob is as follows: 1. Remove the mechanical key, insert a screwdriver into the groove, and gently pry open the cover with the screwdriver. 2. Insert the screwdriver into the gap between the cover and the transmitter, then pry it open and remove the back cover of the key. 3. Remove the battery cover, then take out the old battery. 4. Insert a new battery and replace the battery cover, ensuring the positive side of the battery faces upward.
Changing the battery for the Mazda3 key is something I've done several times, and it's super simple. There's usually a small groove or gap on the back of the key. Just use a coin or a thin card to gently pry open the back cover. Inside, you'll find a CR2025 coin battery. Before removing the old battery, make sure to note which side is the positive terminal (the shiny side faces up) to avoid inserting it the wrong way. Insert the new battery with the shiny side up, then press the cover back on tightly. The whole process can be done at home and takes no more than five minutes. I recommend working on a clean table to prevent dust from getting inside and affecting the contact. I personally use a cheap battery bought from the supermarket, and after replacing it, I test the remote range to ensure both locking and unlocking work properly. Remember to pry the cover gently—don't use excessive force, as it could damage the plastic parts of the key and compromise the seal, making it prone to water damage. If the key buttons start responding slowly or the remote range shortens, it's time to replace the battery. Generally, changing it every two years is a safe bet.
