Hyundai Sonata Key Fob Not Working: How to Fix

The Hyundai Sonata Key Fob is an important component of the car’s security system, but it is not uncommon for it to stop working. If you are facing this issue, don’t worry. Several simple fixes can be done at home without needing to visit a mechanic.

In that case, you’ll just have to check the key fob’s battery, ensure the key is within range of the car, and all the car’s systems are working properly. If the key still does not work, try resetting it by pressing the unlock and lock buttons simultaneously for 15 seconds.

For your help, in this guide, we’ll explain the causes of the key fob not working on the Hyundai Sonata and troubleshoot the issues.

What Is Key Fob In Hyundai Sonata?

A key fob, also known as a remote keyless entry (RKE) system, is a small device with a Hyundai Sonata that allows the driver to lock/unlock the doors and start the engine without using a physical key. The key fob typically has buttons for locking/unlocking and starting the car, and it works by transmitting a signal to the car’s receiver.

How Does Key Fob Work In Hyundai Sonata?

The Key Fob in a Hyundai Sonata uses a radio frequency (RF) communication mechanism. When the driver presses a button on the key fob, it sends a specific RF signal to the car’s receiver near the steering column.

The car’s receiver interprets the signal and performs the requested action, such as locking/unlocking the doors or starting the engine. The car and key fob communicate using encrypted signals to prevent unauthorized access. This system allows the driver to perform certain functions from a distance, providing added convenience and security.

Common Causes of Key Fob Not Working In Hyundai Sonata

Here are some common causes for a Key Fob not working in a Hyundai Sonata, with details:

  • Dead Battery: A dead battery is the most common cause for a Key Fob not working. Over time, the battery will lose its charge and need to be replaced.
  • Signal Interference: Other devices in the vicinity can interfere with the signal from the Key Fob to the car’s receiver, causing it to stop working. For example, cell phones, Wi-Fi routers, and other electronic devices can emit signals disrupting the Key Fob’s signal.
  • Damaged Key Fob: Dropping the Key Fob, getting it wet, or exposing it to extreme temperatures can cause physical damage to the device, making it non-functional.
  • Weak Signal: If the Key Fob is too far from the car’s receiver, the signal may be too weak to activate the requested function.
  • Malfunctioning Car Receiver: In some cases, the issue may lie with the car’s receiver, not the Key Fob. A malfunctioning receiver can prevent the car from receiving the signal from the Key Fob.

Note: If you experience these issues with your Jeep Cherokee, you should fix the push button start not working issue to prevent any further damages.

How to Fix the Hyundai Sonata Key Fob Not Working?

When the key fob isn’t working, it can be a major disruption to your daily routine. Fortunately, you can take a few steps to get your key fob working again. Here’s what you need to know.

  • Dead Battery: To fix the battery issue, simply replace the battery in the Key Fob. Refer to the Key Fob manual for specific instructions on replacing the battery.
  • Signal Interference: To fix the signal interference problem, move the Key Fob closer to the car or away from other electronic devices emitting signals.
  • Damaged Key Fob: If the Key Fob has physical damage, it may need to be replaced. Contact a Hyundai dealer for assistance.
  • Weak Signal: To fix this issue, ensure the Key Fob is within range of the car’s receiver when attempting to use it. Try moving closer to the car or moving it away from other electronic devices that may be emitting signals.
  • Malfunctioning Car Receiver: If the issue lies with the car’s receiver, it may need to be repaired or replaced. Contact a Hyundai dealer for assistance.

How to Reset Key Fob in Hyundai Sonata?

Sometimes, your key fob can become unresponsive, and you’ll need to reset it. Here’s a step-by-step guide to reset your Hyundai Sonata key fob.

  1. Start by locating the key fob in the center console of your Sonata. It should be easy to spot.
  2. Push and hold the unlock button on the key fob for at least five seconds. This will reset the key fob’s memory and allow you to use it again.
  3. Once you’ve held the unlock button down, press the lock button for five seconds. It helps to reset the key fob’s settings and make it work again.
  4. After five seconds, release both buttons, and the key fob should be reset.

How to Resolve Malfunctioning Car Receivers?

Here’s how to resolve malfunctioning car receivers in Hyundai Sonatas:

  • Check the Battery: Ensure the car’s battery is charged and functioning properly. A dead battery can cause the car’s receiver to malfunction.
  • Inspect the Antenna: Check the car’s antenna for any signs of damage or corrosion. If the antenna is damaged, it may need to be repaired or replaced.
  • Check for Loose Connections: Ensure that all connections between the car’s receiver and the rest of the electrical system are tight and secure. This is because loose connections can cause the receiver to malfunction.
  • Clean the Receiver: Dirt, debris, and other contaminants can build up on the car’s receiver over time and cause it to malfunction. In that case, you have to clean the receiver using a soft, damp cloth.
  • Update the Software: Check if any software updates are available for the car’s receiver. Installing the latest software updates can resolve any bugs or glitches that may be causing the receiver to malfunction.
  • Consult a Hyundai Dealer: If the above steps do not resolve the issue, it may be necessary to seek assistance from a Hyundai dealer. They have the expertise and equipment to diagnose and repair the car’s receiver.

Note: If the car’s receiver continues to malfunction after trying these steps, it may need to be repaired or replaced. Contact a Hyundai dealer for further assistance.

How to Improve the Weak Signal from the Key Fob?

Here are ways to improve the weak signal from the Key Fob in a Hyundai Sonata:

  • Change the Battery: A weak signal may indicate a dying battery. Try replacing the battery in the Key Fob.
  • Keep the Key Fob Away from Metal Objects: Metal objects can interfere with the Key Fob’s signal. Keep the Key Fob away from metal objects like keys, cellphones, or other electronic devices.
  • Check the Signal Strength: Check the signal strength of the Key Fob by pressing the lock/unlock button and observing the LED light. If the LED light is weak, the signal may be weak.
  • Relocate the Key Fob: Try moving the Key Fob to different locations to see if the signal improves. The Key Fob may be positioned too far away from the car, or a physical object may block it.
  • Replace the Key Fob: If the above steps do not improve the signal, the Key Fob may be damaged or worn out. Consider replacing the Key Fob with a new one.


A non-functioning Key Fob in a Hyundai Sonata can be a major inconvenience. However, with some troubleshooting and maintenance, most Key Fob issues can be resolved. From checking the battery, to fixing weak signals and malfunctioning receivers, many steps can be taken to improve the performance of the Key Fob.

So, it is important to keep the Key Fob away from metal objects and other electronic devices and perform regular maintenance checks. If the Key Fob continues to cause problems, it may be necessary to seek assistance from a Hyundai dealer.

By following these tips, you can ensure that your Key Fob remains in good working condition and that you have a seamless, stress-free experience using your Hyundai Sonata.

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