Hyundai Sonata Key Fob Not Working: How to Fix

Your Hyundai Sonata Key Fob suddenly stops working, and you’re not sure what to do? Keep reading!

In this post, I’ve explained the common reasons behind this issue and what you can do to resolve it.

In short, a quick way to resolve a non-responsive Hyundai Sonata key fob is to replace the battery. If that doesn’t help, try reprogramming the key fob.

For more details on the causes of key fob issues on your Hyundai Sonata and fixes to apply, keep reading.

Table of Contents

Causes of Hyundai Sonata Key Fob Issues

Dead Battery: One of the most common culprits of a malfunctioning key fob is a dead or weak battery. The key fob requires power to communicate with the vehicle—and if the battery is depleted, it won’t function properly.
Interference: Radio frequency interference from other electronic devices or strong radio signals in the vicinity can disrupt the communication between the key fob and the car’s receiver.
Key Fob Programming Issues: If your key fob was not properly programmed during its setup or if there’s a glitch in the programming, it might fail to communicate with the car.
Physical Damage: Accidental drops or exposure to moisture can damage the internal components of the key fob, rendering it inoperable.
Car Battery Issues: In some cases, if the car’s battery is weak or disconnected, the key fob might not work as expected.

How to Fix ‘Hyundai Sonata Key Fob Not Working’

Replace the Battery

As mentioned earlier, a common reason for a malfunctioning Hyundai Sonata key fob is a depleted or weak battery.

Most Hyundai Sonata key fobs use a coin cell battery (usually a CR2032), and replacing it is a straightforward process. Here’s a step-by-step guide to help you replace the battery in your key fob:

1. Materials Needed:

New coin cell battery (CR2032 or the specific battery recommended by Hyundai) and a small flat-head screwdriver or a plastic pry tool.

2. Prepare the Key Fob:

Find a clean, well-lit workspace where you can comfortably work on your key fob. Ensure that you have a new battery on hand that matches the specifications of the old one.

3. Open the Key Fob:

Examine your key fob to identify the seam or groove along the edges. This is where you’ll insert the screwdriver or pry tool.

Insert the screwdriver or pry tool into the seam and gently apply pressure to pop open the key fob. Work your way around the edges to release the clips holding the two halves together.

4. Access the Battery Compartment:

Once the key fob is open, you’ll see the internal components. Locate the battery compartment; it’s usually a small recessed area designed to hold the coin cell battery.

5. Remove the Old Battery:

Carefully use your fingers or a non-metallic tool to remove the old battery from the compartment. Pay attention to the battery’s orientation, noting which side is facing up.

6. Insert the New Battery:

Take the new battery and ensure its polarity matches the markings inside the battery compartment. The “+” side of the battery should be facing up. Gently place the new battery into the compartment, ensuring it’s securely seated.

7. Close the Key Fob:

Align the two halves of the key fob and press them together firmly until you hear or feel the clips snap into place.

8. Test the Key Fob:

Stand near your Hyundai Sonata and press the buttons on the key fob to test its functionality. Try locking, unlocking, and opening the trunk.

Video tutorial:

If it still doesn’t work, continue to the next steps.

Check for Interference

Radio frequency interference occurs when other electronic devices or strong radio signals interfere with the communication between your key fob and your Hyundai Sonata’s receiver. This interference can disrupt the signals and prevent the key fob from working as expected.

Move away from potential sources of interference, such as large metal objects, other electronic devices, or radio towers.

Attempt to use the key fob again in a different location to rule out interference as the issue.

Reprogram the Key Fob

If your Hyundai Sonata key fob isn’t responding as it should, a programming glitch might be the culprit. Reprogramming the key fob can often resolve communication issues and restore proper functionality.

Here’s how to reprogram your Hyundai Sonata key fob:

Sit in the driver’s seat with all doors and windows closed.
Insert the ignition key and turn it to the accessory (ACC) mode without starting the engine.
Now, press and hold the Unlock or Open button on your key fob until your vehicle’s lights start flashing.

Inspect for Physical Damage

Another reason your Hyundai Sonata key fob is unresponsive is physical damage. Accidental drops, exposure to moisture, or other mishaps can cause internal components to malfunction.

Examine the key fob for visible damage like cracks, dents, or signs of moisture ingress.

If any damage is found, consider replacing the key fob or repairing it through a professional.

Check the Car Battery

If your Hyundai Sonata key fob isn’t working, don’t overlook the possibility that your car’s battery might be the root cause. The key fob requires power from the car’s battery to function properly.

Ensure the car’s battery is charged and properly connected.

You can also try to reset your car by disconnecting the battery. Then wait 30-60 seconds and reconnect the battery.

Now try to use the remote again to see if it works.

Related: How to Fix Hyundai Sonata Horn Issues.

Wrapping Up

Dealing with a Hyundai Sonata key fob that’s not working can be frustrating. But by diagnosing the issue and following the troubleshooting steps outlined in this post, you can resolve the problem yourself.

If you’re unsure about any of the steps or the problem persists, it’s always a good idea to seek assistance from your local Hyundai dealership or a qualified mechanic.