Changing the Battery in Your Mazda 3 Key Fob

There's nothing more frustrating than stepping into your vehicle after a long day, and discovering that the key fob battery is dead. Luckily, it's an easy fix by purchasing the simple replacement of a battery at a hardware store or big box retailer.

A spare key fob for your Mazda 3 is an inexpensive alternative to not having to be towed by a dealership to let them reprogram the keys.

Battery Replacement

Change the battery in your Mazda 3 key fob is an easy procedure that you can perform at home. However, you should only replace the battery when it dies, or if the key fob displays a message on the multi-information display that reads, "Low key fob battery. Replace battery."

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

Once the fob's case is opened, you'll notice the slots on either side of the case that houses the battery. Start on the opposite side of the case and gently lift it up. Remove the old CR2025 and replace it with a new one, making sure that you place it face-up to ensure the correct direction of polarity. Place the battery cap on again and secure both sides of your key fob case by pressing until they click.

After you've replaced the battery, test the fob to confirm it functions by locking and unlocking your doors. If everything is in order you're now able to use the mazda key fob 3's remote functions on the road again!

Pairing Issues

This could indicate that the transmitter in your car may have been damaged. This is usually a matter to a professional and you will need a new 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 faulty. This could happen if the key fob has been dropped on hard surfaces or exposed to saltwater or even touched by dirty hands.

You'll need a small "key" that is inserted into the seam, to remove the circuit board and diagnose the issue. You can then examine the chip for damage or corrosion. It is recommended to clean the paper towel to keep the microchip from being damaged.

If you aren't sure it is possible to check the battery connector's terminals for cracks or broken. If this is the situation, soldering the terminals back into place can usually restore functionality to the key fob. You can also inspect the buttons for wear or damage. If the buttons are loose they can be resoldered into position, unless they've physically snapped.

Interference Signals

There are few things more frustrating than glancing at an "No Fob Detected" message when you attempt to start your car. It usually happens at the most awkward time, such as the time you're late to work or when you have to pick up children from daycare/school. There are some things you can try to figure out what's the cause.

Interference signals can cause the remote key fob to stop functioning properly. This can be caused from objects such as weather conditions, buildings, and transmitters that operate on the same frequency. Interference may occur if your vehicle is equipped with aftermarket equipment that transmits at the same frequency as your key fob.

The key fob can also be damaged if it is exposed to salt water or water. The rubber seals on the chip's electronic components can be penetrated by water, especially in the event that it is submerged for an extended period of time such as in a pool or at the beach. The chip may stop working and require replacement of the keyfob. If you own a programmable key it is possible to clean the chip with isopropyl Alcohol or an electronic cleaner to help it come back to normal. If this doesn't work will be able to fix the issue, then the chip has fried and needs to be replaced.

Locking and unlocking of the Doors

The buttons on the fob's key send electronic signals to the solenoid inside the car, which then converts the signal into mechanical action. This locks and unlocks doors. If the door lock is not working, the problem may be a solenoid issue that requires some investigation with the assistance of a professional auto repair shop.

A dead 12 volt battery could also hinder the fob from working properly. This can occur if your battery fails to charge or if your contacts become corrosion-prone. The good news is that a new battery can fix this issue in just minutes.

The receiver module could be the problem if the key fob won't work after you replace the battery or re-program the device. The device receives radio frequency signals from the key fob and interprets them to control the vehicle's functions. It can be a costly repair if it becomes faulty.

To check if this is the case, Mazda 3 key begin by putting your spare key into the key slot and turning the ignition to ON. Press the key fob two times within 10 seconds, but without taking it out. The Mazda 3 system will now be able to synchronize the key with your car, and you can use it as your primary remote for driving. This allows you to program up three keys.