If your Mazda 3’s key fob is not working, the most common reason is a dead battery. Followed by water damage or fob failure.
Below, we’ve listed everything you need to do to get your car’s fob working again.
A dead battery is the most common reason a Mazda 3’s key fob fails.
Table of Contents
1. Dead Battery
The most common reason a key fob isn’t working is that the battery has died and needs to be replaced.
Some vehicles will display a warning message that the key fob battery is about to die. Depending on your Mazda 3’s model year, it may or may not warn you.
To replace your 3’s key fob battery, you’ll have to pop it open. You can find battery replacement instructions on YouTube for almost any vehicle’s remote. Otherwise, check the owner’s manual.
Once you open it, write down the key fob battery number and get a replacement. The most common size is CR2032.
Starting a Push to Start Vehicle With a Dead Key Fob
Keyless entry systems have been around for a while, but the combination of a push-start button and no physical ignition key is still relatively new. Even if your Mazda 3’s key fob is not working, you can still start your push to start vehicle. Here’s how:
- You’ll need to gain access to your 3 if the doors are locked. Most keyless start vehicles have a physical key hidden in the key fob.
- Look on the back of your fob for a button you can push to slide the fob out. The only tumbler to insert this key is likely the driver’s door.
- Hold the key fob close to the ignition button and press it until the car starts. Try pressing the key into the push start button. The ring around it actively searches for the key fob and should pick it up.
Key Fob Not Working After a Battery Change
If you’ve changed your Mazda 3’s key fob, and it’s still not working it’s likely that you have a damaged circuit board. You may need to reprogram the key to work with your vehicle.
Most vehicles’ key fobs work the same way. Consult your owner’s manual for instructions on reprogramming the key fob.
This video is a fantastic resource on how to get most vehicles to recognize their key fob again after changing the battery.
2. Out of Range
The second reason your key fob might not work is that it’s out of range from your 3.
Key fobs generally have a range of about 30 feet, so if you’re too far away from your car, it won’t respond.
Be sure to check that the key fob is close enough before trying to start your Mazda 3. If it works when you get close, it almost certainly has a low battery.
3. Water Damage
The third reason why your Mazda 3’s key fob might not be working is that it’s been exposed to water.
If your key fob has gotten wet, the circuits may have shorted out or corroded and will need to be replaced.
Take your car to a professional auto locksmith or a dealer who can program a new key fob for you.
4. Reprogramming Required
Your 3’s keypad may need reprogramming. This is usually the case if you’ve you’re using a fob that didn’t originally come with your car.
To reprogram your key fob, consult your car’s manual or contact a local mechanic to help.
5. Key Fob Failure
Another reason could be that there is a problem with the internal circuitry in your key fob, which can happen from wear and tear over time.
If this is the case, you will likely need to replace your Mazda 3’s key fob.
If you have recently changed your car’s battery or had the electronics in it serviced, then this could also be the cause of your key fob not working.
In this instance, you will need to reprogram your key fob with your car’s onboard computer. You should only suspect the computer needs reprogramming if BOTH key fobs don’t work.