Changing the Battery in Your Mazda 3 Key Fob It's a pain to pull into your car 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 A spare key fob for your Mazda 3 is an inexpensive alternative to not having to take your vehicle to a dealership in order to have them reprogram the keys Battery Replacement You can change the battery on your Mazda 3 keyfob at home But, you should only replace the battery when it is dead, or if the key fob shows a message on the multi-information display, "Low key fob battery Replace battery" You'll need an flathead screwdriver along with tape and patience to open the case Find a gap or notch in the bottom portion of the metal of the Mazda 3's key fob and then insert the head of the screwdriver into it to pry off the lower portion Repeat this procedure for the top metal piece Be careful not to scratch the rubber ring at 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 on one side and then shifting to the other Remove the old battery, and put in a new CR2025 and make sure it's in the right orientation for proper polarity Then, put the cap on the battery and reattach both sides of the key fob case Keep pressing until you hear them click Once you've replaced your battery, test the fob to ensure it's working by locking and unlocking your doors If everything is in order then you can begin using your Mazda 3's remote features for the first time Pairing Issues This could be a sign that the transmitter in your car has been damaged This is usually a matter to a professional and you will need a new key fob If you've tried to change the battery and reprogram the key fob, but it hasn't worked it is possible that the chip inside the key fob might be defective This could happen if the keyfob was dropped or exposed to saltwater or was touched by dirty fingers You'll need to find an extremely small "key" that is built into the seam, to remove the circuit board and diagnose the problem Then, you will be able to check for any damage or corrosion on the chip It is recommended to use a clean paper towel to prevent damaging the microchip If you aren't sure then you should also examine the battery connector terminals for cracks or broken If this is the case, then carefully connecting them back can often restore the function of the key fob Similarly, you can inspect the buttons to determine whether they've been worn out or damaged If the buttons are loose, they can be soldered back into place regardless of whether a button has physically snapped off Interference Signals There are few things more frustrating than trying to get the engine started in your car and seeing the message "No Fob Detected" It usually happens at the most inconvenient moments, like when you're running late for work or picking up children from daycare/school 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 not to function properly This could be caused by things like buildings, weather conditions and transmitters that use the same frequency Interference could occur if your vehicle has aftermarket equipment that transmits at the same frequency as your key fob In addition, if the key fob is exposed to water or salt water it may be damaged Water can damage the rubber seals of the electronic chip particularly if the key fob is submerged in water for a long time The chip can stop working and require replacement of the keyfob If you have a programable key, you can clean the chip with isopropyl Alcohol or an electronic cleaner to aid in its come back to normal If this doesn't work, it is likely that the chip is fried and requires replacement Locking and unlocking of the Doors The buttons on the key fob send electronic signals to the solenoid in the car, which transforms the signal into mechanical action This locks and unlocks doors If https//wwwthekeylabcouk/mazda-car-keys/ isn't working, the problem could be a solenoid issue that requires some investigation with the help of a professional auto repair shop A low-voltage battery can also stop the fob from functioning correctly This can happen if the battery loses its charge or the contacts become corroded, and stop transferring electricity The problem can be addressed in minutes with a new battery The receiver module could be the cause if the key fob doesn't work after you replace the battery or reprogram the device This device interprets radio frequency signals sent by the key fob to control the vehicle It could be a costly repair if it malfunctions To check if this is the case, start by putting your spare key into the key slot and turning the ignition to ON Press the key fob twice in a period of 10 seconds, without taking it out The Mazda 3 system synchronizes the key to the vehicle and you can now use it as your primary driving remote You can program up to three keys in this way