Changing the Battery in Your Mazda 3 Key Fob

It's frustrating to get into your car at the conclusion of a long and tiring day and find that the key fob is dead. Fortunately, this is an easy fix by purchasing a simple battery replacement from the hardware store or big box retailer.

Incorporating a spare key fob to your Mazda 3 can be an affordable way to keep yourself from having to be taken to the dealer and having them re-program your keys.

Battery Replacement

You can replace the battery on your Mazda 3 keyfob at home. However, you should only replace mazda key the battery when it dies, or if the key fob displays a message on the multi-information display stating, "Low key fob battery. Replace battery."

You'll need to use an flathead screwdriver along with tape and patience to open the case. Insert the head of the flathead screwdriver in a notch or gap, on the bottom metal of the Mazda 3 key fob to cut off the lower half. Repeat the process for the top piece of metal Be careful not to scratch the rubber ring on the bottom of the case.

When the fob case is open, you'll see the slot on either side of the case that houses the battery. Use the tape-wrapped flathead screwdriver to gently pry the case open, beginning on one side before moving to the next. Remove the old battery and put in a new CR2025, making sure that it's in the right orientation for proper polarity. Finally, place the cap back on and then reattach both sides of the key fob's case. Continue pressing until you can hear them click.

After replacing the battery, test the fob to ensure it works by locking and unlocking your doors. If everything is in order you're good to go. Mazda 3 remote features can be used again.

Pairing Issues

This could be a sign that the transmitter in your car may have been damaged. It is usually a job to a professional and you require a new key fob.

If you've tried replacing the battery and reprogramme the key fob, but it hasn't worked the chip inside the key fob might be faulty. This can occur if the key fob has been dropped on hard surfaces and exposed to salt water or even touched by dirty hands.

To identify the issue it is necessary to find a small "key" that is embedded into the seam of the fob that lets you take it apart and remove the circuit board. You can then examine the electronic chip for damage or corrosion. To prevent damaging the chip, it is recommended to use a clean paper towel.

It is also possible to take a close look at the battery connector's terminals to determine if they're damaged or cracked. If this is the case it is possible to solder the terminals back into place can usually bring back functionality to the key fob. It is also possible to check the buttons for wear or damage. If the buttons are loose, they can easily be soldered back into place as well unless the button has actually snapped off.

Interference Signals

Few things are more annoying than staring at an "No Fob Detected" message when trying to start your vehicle. This usually occurs at the most awkward time, such as when you are late for work or picking up children from school/daycare. The good news is that there are steps you can take to pinpoint the issue and determine the cause.

Interference signals can cause the remote key fob to stop functioning in a proper manner. It can be caused by things like weather conditions, buildings, and transmitters using the same frequency. Interference can also occur when you have equipment from an aftermarket manufacturer installed in the vehicle that transmits at the same frequency as the key fob.

Additionally, if the key fob is exposed to salt or water waters, it could be damaged. The rubber seals on the electronic chip can be damaged by water, especially if it is submerged for an extended period of time like in a swimming pool or at the beach. This can cause the chip to stop functioning and require replacement of the key fob. If you have a programmeable key cleaning the chip using isopropyl alcohol or an electronic cleaner to aid in its return to working. If this doesn't work will be able to fix the issue, then the chip has been damaged and requires replacement.

Locking or Unlocking the Doors

The buttons on the keys send electronic signals to a solenoid inside the car. It transforms the signal into a mechanical action that locks and unlocks doors. If the door lock does not work, it could be an issue with the solenoid. This will require professionals from auto repair shops to examine.

A dead 12V battery can also stop the fob from functioning effectively. This is the case if the battery's charge is lost or the contacts get corroded and stop transferring electricity. The good news is that a new battery can solve this issue in only minutes.

The receiver module could be the reason why the key fob won't work after replacing the battery or program the device. The device interprets radio frequency signals transmitted by the key fob to control the vehicle. If it fails it could be costly to repair.

To check if this is the case, start by inserting your spare keys into the key slot and setting the ignition to ON. Press the key fob twice for 10 seconds without taking it out. The Mazda 3 system will now connect the key to the car, and you can use it as your primary remote for driving. You can program up to three keys this manner.