Changing the Battery in Your Mazda 3 Key Fob

It is frustrating to get in your car at the end of a long, hard day and discover that the key fob is dead. This is a simple fix that is easily done at a major box retailer or at a hardware store.

Incorporating a spare key fob to your Mazda 3 can be an cost-effective way to stay away from having to be taken to the dealer and having them reprogram your keys.

Battery replacement mazda key

Changing the battery in the Mazda 3 key fob is a simple process that you can do at home. It is recommended to replace it if the battery fails or you notice a message stating "Low keyfob battery" on the multi-information display. Replace battery."

You'll need to use a flathead screwdriver with tape and patience to open the case. Find a gap or notch in the bottom part of the metal of the Mazda 3's key fob, and then insert the head of the screwdriver to cut off the lower part. Repeat the process for the top piece of metal Be careful not to damage the rubber ring at the bottom of the case.

You'll find a slot on each side of the fob case that contains the battery. Start on the opposite side of the case and then gently pry it open. Remove the old battery and put in a new CR2025 to ensure that it's face-up for proper orientation. Place the battery cap on again and secure 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 test that the fob works. If everything appears to be working then your Mazda 3 remote features can be used again.

Pairing Issues

This could mean that the transmitter in your car is damaged. It's usually a task for a professional, and you will require a new key fob.

If you've tried to replace the battery and reprogram the key fob, but it hasn't worked the chip inside the key fob may be faulty. This can happen when the key fob was dropped on hard surfaces or exposed to salt water or even brushed by dirty hands.

You'll need to find the tiny "key" that is built into the seam to remove the circuit board and identify the problem. You can then check the electronic chip for corrosion or damage. It is best to use a clean, dry paper towel to prevent damaging the microchip.

It is also possible to take a close look at the battery connector terminals to see if they are cracked or broken. If this is the case, carefully reconnecting them can generally restore the functionality of the key fob. You can also check the buttons for damage or wear. If the buttons are loose they can be resoldered into place, unless one has physically snapped.

Interference Signals

There's nothing more difficult than trying to start your vehicle and getting the message "No Fob Detected". This usually occurs at the most difficult moments, like when you're late for work or when you have to pick up children from daycare or school. There are several things you can do to troubleshoot and find out what's the cause.

Interference signals can affect the remote key fob's signal to the vehicle making it unable to work properly. This could be caused by objects like buildings, weather conditions and transmitters that operate on the same frequency. Interference may also occur if 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 seawater, it may be damaged. Water can get into the rubber seals of the electronic chip, particularly in the event that the key fob is submerged in water for an extended duration. This could cause the chip's function to cease and require replacement of the key fob. If you have a programable key it is possible to clean the chip with isopropyl alcohol or an electronic cleaner to aid in its return to working. If this doesn't work, the chip is likely to be damaged and needs to be replaced.

Locking/Unlocking the Doors

The buttons on the keys send electronic signals to a solenoid inside the car that then transforms the signal into a mechanical action that locks and unlocks the doors. If your door lock fails to work it could be because of an issue with the solenoid. This requires professional auto repair shops to examine.

A dead battery of 12 volts can also prevent the fob from functioning properly. This could happen if the battery loses its charge or the contacts are corroded and stop transmitting electricity. The good news is that a new battery is able to resolve this issue in a matter of minutes.

If the key fob won't work after you replace the battery or try to program it again then the problem may be in the receiver module. The device receives radio frequency signals from the key fob and interprets them into controlling the vehicle's functions. If it breaks down it could cost a lot to repair.

To determine whether this is the case, begin by inserting your spare keys into the key slot and turning the ignition to ON. Press the key fob button three times within 10 seconds without taking it. The Mazda 3 system will now connect the key to the car and allow you to use it as your primary remote for driving. This lets you program up three keys.