Changing the Battery in Your Mazda 3 Key Fob
There's nothing more annoying than getting in your vehicle after a long work day and finding that the key fob battery is dead. This is a simple fix that is easily done at a major box retailer or at a hardware store.
A spare key fob for your Mazda 3 is an inexpensive way to avoid having to take your vehicle to a dealer to have them reprogram the keys.
Battery Replacement
You can replace the battery on your Mazda 3 keyfob at home. However, you should replace the battery when it goes out of service, or if the key fob shows a message on the multi-information display stating, "Low key fob battery. Replace battery."
To open the case of your key fob you'll need a tape-wrapped flathead screwdriver and some patience. Put the flathead screwdriver's head in a notch, or gap, on the bottom metal of the Mazda 3 key fob to pry the lower half off. Repeat this process for the top metal piece Be careful not to scratch the rubber ring that is at the bottom of the key fob's case.
When the fob case is open, you'll see the slots on either side of the case that houses the battery. Start on mazda cx 5 keys locked in car of the case, and then gently lift it up. Remove the old battery and put in a new CR2025 to ensure that it's face-up for proper orientation. Put the cap of the battery on the other side and attach both sides of your key fob case by pressing until they click.
After you've replaced the battery check the fob to verify that it functions by locking and unlocking your doors. If everything is in order then you can begin using your Mazda 3's remote capabilities for the first time!
Pairing Issues
If your key fob has stopped working suddenly it could be a sign that the transmitter in the car has been damaged. It is typically a need for a professional to repair and may need a new key fob.
If you've tried to replace the battery and reprogram the key fob, but it hasn't worked then the chip in the key fob may be defective. This can happen if your keyfob has been dropped, exposed to saltwater, or was touched by dirty fingers.
To identify the issue it is necessary to locate a tiny "key" located in the seam of the fob that lets you take it apart and remove the circuit board. Then, you can examine the chip for damage or corrosion. It is best to use a clean, dry paper towel to prevent damaging the microchip.
It is also possible to examine the battery connector terminals to examine if they're damaged or cracked. If this is the case you can solder the terminals back into place can usually restore the functionality of the key fob. In the same way, you can examine the buttons to see whether they're worn or damaged. If the buttons are loose, they can easily be soldered back in place as well unless the button is physically snapped off.
Interference Signals
There are few things more difficult than trying to start your vehicle and getting the message "No Fob Detected". This usually occurs at the most inconvenient times, such as when you're running late for work or if you're picking up kids from school/daycare. The good thing is that there are a few steps you can take to investigate the issue and figure out the root of the problem.
Interference signals can cause the remote key fob to stop functioning properly. This can be caused by things like weather conditions, buildings, and transmitters that operate on the same frequency. Interference could occur if your vehicle has aftermarket equipment that transmits at the same frequency as your key fob.
The key fob could be damaged if it is exposed to water or salty water. The rubber seals on the electronic chip could be damaged by water, particularly when it is submerged for an extended period of time such as in a pool or at the beach. The chip may cease to function and may require replacement of the keyfob. If you own a programmable key, you can clean the chip using isopropyl alcohol or an electronic cleaner to aid in its return to functionality. If this doesn't work the chip, it's likely fried and will need to be replaced.
Locking or Unlocking the Doors
The buttons on the keys send electronic signals to a solenoid inside the car. It then transforms the signal into a mechanical action that locks and unlocks doors. If the door lock isn't working, the issue may be a solenoid issue that requires some investigation by an expert repair shop for autos.
A dead 12 volt battery can also prevent the fob from functioning correctly. This could happen if the battery fails to charge or if your contacts become corrosion-prone. This issue can be resolved in a matter of minutes by replacing the battery.
The receiver module may be the reason why the key fob doesn't work after you replace the battery or re-program the device. This device receives radio frequency signals from the key fob and interprets them to control the functions of the vehicle. It could be a costly repair if it becomes faulty.
To test if this is true, place your spare key in the key slot. Then turn the ignition on. Press the key fob two times in 10 seconds, without removing it. The Mazda 3 system will now synchronize the key with the car and you can use it as your primary remote for driving. This lets you program up to three keys.