Changing the Battery in Your Mazda 3 Key Fob

It is frustrating to drive off at the end of a long workday and discover that your key fob is dead. This is a simple fix that is easily done at a big box retailer or hardware store.

Adding a spare key fob to your Mazda 3 can be an affordable solution to free yourself from having to be towed to the dealership and having them reprogram your keys.

Battery Replacement

Changing the battery in the Mazda 3 key fob is an easy task that you can perform at home. But, you should only replace the battery if it goes out of service, or if the key fob displays a message in the multi-information display, "Low key fob battery. Replace battery."

You'll need to use a flathead screwdriver, tape and patience to open the case. Locate a notch or gap in the bottom metal part of your Mazda 3's key fob, and then insert the tip of the screwdriver in it to break off the lower half. Repeat the process for the top metal piece Be careful not to scratch the rubber ring on the bottom of the case.

You'll find a slot on each side of the case, which houses the battery. Start with one side of the case and then gently open it. Remove the battery that was used and place in the new CR2025 ensure that it's facing upwards to ensure proper polarity. Attach the cap to the battery again and attach both sides of your key fob case by pressing until they click.

After replacing the battery After replacing the battery, lock and unlock your doors to confirm whether the fob is working. If everything looks good, you can start using the mazda key 3's remote functions to drive again!

Pairing Issues

If your key fob has stopped working suddenly it could be because the transmitter in the car has been damaged. This is usually a matter of a professional to repair and will likely require a replacement key fob.

If you've attempted to replace the battery and reprogramme the key fob but it's not working the chip inside the key fob may be defective. This can happen if your keyfob was dropped, exposed to saltwater, or the touch of dirty fingers.

To determine the cause it is necessary to locate a tiny "key" located in the seam of the fob that lets you lift it open and remove the circuit board. You can then examine the electronic chip for corrosion or damage. It is best to use a clean paper towel to ensure that the chip is not damaged.

You can also take a closer look at the battery connector's terminals and see if they are damaged or cracked. If this is the case, then carefully connecting them back can often restore the function of the key fob. You can also check the buttons for damage or wear. If the buttons are loose, they can be soldered back into position, unless they've physically snapped.

Interference Signals

There is nothing more frustrating than glancing at a "No Fob Detected" message when trying to start your car. It happens at the worst situations, like the time you're late to work or when you have to pick up your children from daycare or school. The good news is that there are a few steps you can take to investigate the issue and figure out what is causing it.

Interference signals can disrupt the remote key fob signal from the vehicle which causes it to not function properly. This could be due to objects such as weather conditions, buildings and transmitters that operate on the same frequency. Interference can occur when your vehicle has aftermarket equipment that transmits at the same frequency as your key fob.

The key fob might be damaged if exposed to water or salty water. The water can penetrate the rubber seals of the electronic chip particularly in the event that the key fob is submerged in water for a prolonged time. The chip may cease to function and require replacement of the keyfob. If you own a programmable key cleaning 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 and Unlocking the Doors

The buttons on the key fob send electronic signals to the solenoid inside the car, which transforms this signal into a mechanical action. It locks and unlocks doors. If your door lock fails to work, it could be an issue with the solenoid. This will require professionals from auto repair shops to investigate.

A dead 12 volt can cause the fob to stop working properly. This could happen if the battery loses its charge or if the contacts become corroded. The problem can be addressed in a matter of minutes by replacing the battery.

The receiver module may be the problem if the key fob won't work after replacing the battery or program the device. This device receives radio frequency signals from the key fob and interprets them to control the functions of the vehicle. It can be expensive to repair if it becomes faulty.

To determine if this is true, insert your spare key in the key slot. Then turn the ignition on. Press the key fob twice within 10 seconds without removing it. The Mazda 3 system will now connect the key to the vehicle and you can then use it as your primary remote for driving. This allows you to program up three keys.