Updated at: 27-07-2023 - By: Lucas

The fundamental obligation of any car owner is to guarantee the machine is running efficiently whenever called to action. However, issues develop.

As most current automobiles use electronic control units, faults can impede our intentions, whether mechanical or electronic parts.

Most vehicles currently rely on key fobs or electronic car keys to work. Key fobs handle practically every function when you wish to run your car.

For instance, you need the key fob to unlock the car, start the engine, open and close the trunk, handle the alarm system, and even power windows.

But key fobs use batteries to function, and at some point, the battery empties. So you will need to replace it. Unfortunately, the key fob battery can fail to work after replacing the key fob battery.

So, what could be the problem?

And what could be the source of such problem?

This is a concern many car owners rely on the key fob for most basic experiences.

Your car’s key fob can not operate after replacing the battery because of several difficulties including.

  • You mishandled the key fob circuit
  • The key fob’s buttons are worn out
  • The key fob is spoiled and many other reasons

Luckily, these problems may be remedied and get your key fob on track. Keep reading to discover more about these and other causes of key fob failing to work after changing the battery.

Why is my Key Fob not Working after Replacing the Battery?

Hyundai Key Fob Not Working After Battery Change

Your key fob can have other faults that never emerged until you changed the battery. So, when you replace the key fob’s battery, several complications could stop it from functioning. Let us dig further into these problems.

Worn out Key Fob Buttons

Key fob buttons are not there to stay forever therefore they will wear out over time. Sometimes, the buttons could be worn out but remain in touch with the circuit.

However, with minimal interference when charging the battery, the buttons cease to function. You can observe this by continuously pressing the button when the button functions after squashing it in a certain way or when one button functions and the other does not.

Also, if the covering plastic is out of place, it suggests a problem in the key fob. You can open the remote and align the buttons to generate contact with the circuit, and if it fails, you get another key fob.

Broken Door Lock

Sometimes difficulties coincide. When you change the key fob batteries, your automobile lock can fail to work, not because of the key fob but because the lock is faulty and the problem has now arisen.

This might leave you wondering, but it is easy to discover this problem. These signs can assist you recognize if the lock has a problem.

  • The lock fails to function even after opening it manually or with a key.
  • The key fob opens some door locks.
  • The door locks fail to open, whereas the signal light has flashed.
  • The lock moves without thoroughly engaging or disengaging.

Spoilt key fob

Car key fobs can easily degrade owing to specific circumstances like water. But these problems could not arise until there is a tiny change in the key fob. So, when you change the key fob battery, it can fail to work. Some symptoms can confirm the key fob is spoilt. They include:

  • The spare key is working
  • Buttons failure to move
  • The key fob is broken
  • If the key fob is damaged, the only solution is to replace it.


When you change the key fob’s battery, great possibilities are the key will reset and will fail to function after that. These two indications can help you realize the situation quickly.

  • If all spare key fobs fail to function too
  • The key fob entirely stop functioning

If this is the situation, you can summon a professional to reset the key fob or do it yourself by following these procedures.

  • After changing the battery, get in the car and close all the doors to avoid reset process disruption.
  • Turn on the vehicle’s ignition system without starting the engine.
  • Press and hold the remote’s lock button and turn off the vehicle key. Repeat the process three or four times.
  • After the third step, listen for the car’s lock sound, which indicates you have entered the key fob’s programming mode. After the sound, press the remote lock button again within five seconds.
  • If there are other remotes you want to program, this is a significant step. After entering the programming mode, press the key fob’s lock button within ten seconds. This will program the other additional remotes.
  • Turn off the car’s ignition system to close the programming process.
  • Step out of the car and lock all the doors to test the key fob. Test all the lock and unlock buttons to affirm the key fob is appropriately functioning.

However, this programming approach does not work on all vehicles, therefore you should first consult before performing the process to avoid destroying your vehicle’s ECU.

Does Resetting the Key Fob Fix the Issue?

Hyundai Key Fob Not Working After Battery Change

If the key fob problem arose from resetting itself after changing the battery, resetting the key fob can fix the problem. However, if the origin of the key fob problem was not resetting itself, this approach cannot fix the problem. Also, you should never attempt to reset the key fob without consulting because some vehicles ECU might be destroyed.

Should you Reprogram the Car after Replacing the Battery?

After changing the battery, you will need to reprogramme the vehicle. Changing the battery, as previously stated, causes havoc with the car’s usual operation. Resetting it will be necessary as a result.

Can you start a Hyundai car Without a Key Fob?

Using a smartphone, you may unlock your Hyundai with a digital key. If your key fob stops working, you can rely on this app.

Unfortunately, the app can only be used with certain Android devices and is only accessible via NFC. The digital key feature must be enabled on one of the specified Android smartphones in order to unlock and start your Hyundai without a key fob.

With a dead key fob, how do you start a Hyundai vehicle?

Hyundai vehicles are one of a kind in that they may be started using a dead key fob. You may use a dead key fob to start your Hyundai in two ways.

  • Use the end or back of the dead key fob to press the start button while pressing the brake.
  • Put the dead key fob in the smart key slot with buttons facing up and press the start button while pressing the brake.


Key fobs for most current vehicles are powered by batteries that need to be replaced after a period of time.

There are a variety of reasons why a key fob battery change may result in a malfunctioning key fob. Some key fob issues can be resolved, while others necessitate a new key fob.

Keeping your key fob in working order can be accomplished in a number of ways. The most important thing to remember is that after changing the batteries in your key fob, you will have to re-program the automobile.

You may start your Hyundai vehicle even if your key fob is dead by going through the above listed steps. Having a basic understanding of these key fobs will allow you to address any problems that may emerge when you are in a remote location.

If you notice any of the above indicators, it will be much easier for you to identify the root of the issue and find a solution.