Changing the Battery in Your Mazda 3 Key Fob
There's nothing more annoying than stepping into your car after a long day, and discovering that the key fob battery is dead. Fortunately, it is an easy fix with the simple replacement of a battery at an hardware store or a big box retailer.
Adding a spare key fob to your Mazda 3 can be an cost-effective way to stay away from the hassle of being transported to a dealership and having them reprogram your keys.
Battery Replacement
You can change the battery on your Mazda 3 keyfob at home. But, you should only replace the battery if it goes out of service, or if the key fob shows a message on the multi-information display that reads, "Low key fob battery. Replace battery."
You'll need to use a flathead screwdriver and tape and patience to open the case. Locate a notch or gap in the bottom portion of the metal of your Mazda 3's key fob, and insert the head of the screwdriver into it to cut off the lower part. Repeat this procedure for the top metal part, but be careful not to damage the rubber ring at the bottom of the key fob's case.
Once the fob case is open, you'll see a slot on either side of the case, which houses the battery. Use the flathead screwdriver with tape to gently pry open the case, beginning with one side and moving to the other. Take out the old CR2025 and replace it with a brand new one, making sure to place it face-up to ensure proper direction of polarity. Then, put the cap of the battery back on and reattach both sides of the key fob case, pressing until you can hear them click.
After replacing the battery Test the fob to confirm it is working by locking and unlocking your doors. If everything is working you're now able to use your Mazda 3's remote features to drive again!
Pairing Issues
This could mean that the transmitter inside your car is damaged. This usually requires a professional to repair and may need a new key fob.
If you've attempted to replace the battery and reprogramme the key fob but it hasn't worked, the chip inside the key fob could be defective. This can occur if the key fob was dropped on hard surfaces and exposed to salt water or even touched by dirty hands.
To diagnose this issue You will need to locate a tiny "key" that is embedded into the edge of the fob which allows you to lift it open and remove the circuit board. You will then be able to check for any corrosion or damage on the chip. It is recommended to use a clean paper towel to ensure that the chip is not damaged.
It is also possible to take a closer look at the battery connector's terminals and examine if they're cracked or broken. If this is the case it is possible to solder the terminals back to their original position will usually bring back functionality to the key fob. Similarly, you can inspect the buttons to see whether they've been worn out or damaged. If the buttons are loosened, they can be resoldered to their original position unless they have physically snapped.
Interference Signals
There are few things more frustrating than trying to start your car and seeing the message "No Fob Detected". This can happen at the most inconvenient situations, like when you're running late to work or you're trying to collect your children from daycare/school. There are some things you can do to find out what's causing the issue.
Interference signals can disrupt the remote key fob's signal from the vehicle making it unable to function properly. This could be due to objects such as weather conditions, buildings and transmitters using the same frequency. Interference may occur if your vehicle has aftermarket equipment that transmits at the same frequency as your key fob.
The key fob may also be damaged if exposed to salt water or water. The rubber seals on the electronic chip could be damaged by water, especially when it is submerged over long periods of time, such as in the ocean or a pool at the beach. The chip may stop working and require replacement of the keyfob. If you have a programmeable key it is possible to clean the chip using isopropyl alcohol or an electronic cleaner to aid in its come back to normal. If this does not help the chip, it is likely to be damaged and will need to be replaced.
Locking/Unlocking of the Doors
The buttons on the key fob transmit electronic signals to the solenoid inside the car. It converts that signal into a mechanical action that locks and unlocks the doors. If the door lock does not work it could be due to an issue with the solenoid. This requires expert repair shops to look into.
A dead 12 volt can also hinder the fob from working properly. This can happen when your battery is not charged or if your contacts become damaged. The good news is that a new battery is able to fix this problem in just minutes.
The receiver module could be the cause if the key fob doesn't work after replacing batteries or reprogram the device. The device detects radio frequency signals sent by the key fob to control the vehicle. It could be a costly repair if it becomes faulty.
To determine if mazda key fob replacement is the case, start by inserting your spare keys into the key slot and turning the ignition to ON. Press the key fob button two times within 10 seconds without taking it. The Mazda 3 system synchronizes the key with the vehicle, so you can use it as your primary driving remote. You can program up to three keys this manner.