Unless you drive around in your grandpa’s car, you would know what a car key fob is! They are convenient keyless entry systems or car remotes to lock and unlock your car.

A car key fob has a short-range radio transmitter that sends a coded signal to the car’s receiver which decodes it and then authorizes the immobilizer to lock/unlock the car doors. All these have to work in tandem to perform their functions. A glitch in the system can lock you out of your car.

A car key fob is a part of the keyless entry system and it is crucial that it works properly. But sometimes, you’ll not be able to lock or unlock the car door when the key fob doesn’t transmit the signal or the receiver doesn’t decode it. Let’s see some of the reasons why a key fob may not work properly.

1. Damaged key fob

You don’t know if everything is proper inside the key fob. Sometimes, a wire may have come off or there might be damage due to water or moisture inside it. The electronics or the transmitter inside the fob may go wrong. Usually, there is wear and tear when you use it for years together. Also, a simple dropping of the keys can also damage the internal components. When the key fob is damaged, it stops working and prevents the car from locking and unlocking. Contact automotive locksmith services to get the key fob repaired.
If the key fob is beyond repair, you may have to go in for a car key replacement. The locksmith makes an assessment and decides the best course of action to be taken for the key fob.

2. Dead battery in the key fob

If your car is not responding to the signals sent from the car key fob, it is likely that the batteries of the fob are dead. You can know it when you have to press the button multiple times for it to send signals. Also, sometimes, the car doesn’t respond to signals from far. You’ll have to come closer to the vehicle for it to respond to the key fob signal. If it is the case, try replacing the batteries with new ones and see if the fob is working.

3. the Wrong key

Sometimes you pick the wrong car key when in a hurry. A key fob works for a specific vehicle. If you press the button of the wrong key fob, your car isn’t going to unlock. So, always make sure you pick the right car key.

4. Carlock issue

The car key fob isn’t the culprit always, right? Sometimes, there might be an issue with the car lock. If the lock gets jammed or when the internal mechanism gets damaged due to an attempted intrusion, the car door won’t unlock even after pressing the car key fob button.
To know if the car lock is at fault, insert the key and see if it turns. There are two possibilities. One is it turns but the car doesn’t get unlocked and the other is it doesn’t turn. If it is either of the two, your car lock is faulty. If the door unlocks, your car key fob is having an issue. For damaged car locks, reach out to automotive locksmith services to resolve the issue quickly.

5. Signal interference

Let’s first learn how a car key fob works to understand the signal interference issue. When a user presses the unlock button on the key fob, a short-range radio transponder in the key fob sends a distinct coded signal to the receiver unit in the car. The receiver unit decodes the signal and when there is a match in the code, it authorizes the car door control unit or the immobilizer to unlock the door. Some of the advanced key fobs can be used to start the engine remotely in addition to locking and unlocking the car and its trunk.
If another wireless device is in the close vicinity of your car, there’s every possibility that it transmits signals at the same frequency as that of your car’s key fob. At such times, your key fob will not work properly preventing you from locking or unlocking the door.

6. Not recognizing the code

As mentioned above, a car key fob has a microchip inside it that transmits a signal to the car. The car has onboard computers or receivers that recognize the microchip inside the car key fob and reads the unique code sent by it. But sometimes, there is a problem when the transponder key’s code cannot be read. When this happens, car key fob programming is required.
Reprogramming a transponder key is not an easy task as some claim it to be. Even though some car manufacturers provide manuals to do it, we suggest you contact automotive locksmith services to complete car key fob programming without any glitches.

7. Broken button contacts

Buttons getting stuck is a common issue in the car key fob. They get misaligned or the contact gets broken resulting in a non-operational car key fob. Sometimes, the car lock button is functional whereas the unlock button isn’t. The buttons simply do not press or are loose. In such cases, you’ll have to open the fob and make the necessary adjustments. If you aren’t comfortable, take the fob to your local locksmith service in Phoenix and get it repaired.

8. Car battery issue

The transponder inside the car needs battery power to remain operational. But if your car battery is dead or faulty, your car door will not unlock in spite of you pressing the button in the car key fob.

9. Using a cheap aftermarket key fob

You receive two keys for your car when you buy it from the dealer. But sometimes, you misplace your car key and in such circumstances, you are forced to make a duplicate. Other times, considering the costs involved, you may go in for a cheap aftermarket key. The problem with aftermarket keys is that they are poorly designed and their electronics are of sub-par quality. Even if you go in for a car key fob programming on it, there are chances it will stop working after a few days.

10. Duplicate key

It’s the same story with duplicate keys. They are never original and so a bit of information is lost in the transfer. A poorly copied key means a given disaster later, if not now. In such cases, contact a trusted car locksmith to make a new key from the vehicle code. And get the replacement key programmed by a skilled locksmith.


For many, a car is the only mode of transportation and when your key fob is not working properly, it is a hassle that you would want to solve at the earliest. Don’t panic. Half of your work is done when you try to understand where the problem is. Your next step is to take the help of automotive locksmith services so that they get the car key fob to work again.
If you are residing in Phoenix and its surrounding areas, you can contact us contact us for help. Desert Locksmith provides you with 24-hours locksmith services. We have specialists who will come to where your vehicle is and help you get up and running quickly.