The key fob for your Mazda has a built-in chip that’s programmed so your security system will both recognize and accept it - allowing you to open your doors. You obviously use your keyless remote to open your Mazda door because it is convenient. When it stops working, the first thing you want to do is fix it. Before you head off to buy a new remote, there are a few other things that you can do to try and get it to work again.
Reset The System
Simultaneously hold the open and the lock button down for 60 seconds. This should reset the system. If it worked, the interior car lights will go on and off. You may even hear the horn beep.
If this did not work, then use the key to unlock the car. Get in it and drive it. Sometimes just having the key in it and driving it will reset the alarm. This will allow your keyless remote to start working.
If both transmitters are not working, then there may be a problem in the receiver. You can test it by grounding the receiver wire. Once you ground it, the locks should cycle. If they do not, then the problem is in the receiver. You may need to locate your owner’s manual to get the location of the receiver wire.
If the other remote works, you may have a bad battery. Open the key fob case and put a new battery in. Any fob over one-year-old probably needs a new battery. Locate the transmitter and ground it. Push the buttons that lock and unlock the remote until you hear it cycle. It usually takes 10 seconds. Do this for every remote you have up to four. Now, you can take the ground off the transmitter wire and try out the remote.
If you do not want to ground the wire, then you can turn the car on and off. Do this eight times within 10 seconds. This alerts the security system that you are going in the programming mode. You can then press a button to synchronize your transmitter to the security system. You can do up to four transmitters. Turn the ignition to the OFF position and test your transmitters.
If you do not know how to ground a wire or are still having trouble with the remote entry, you may need to program it. (We provide instructions for re-programming the Mazda3 fob here.) If you're still stuck, contact your local Mazda dealership for assistance.