Car Not Detecting Key Fob – 5 Reasons & How To Diagnose

A major issue most old car owners face is their car failing to start smoothly. Performance issues are perfectly normal when your car has chalked up some mileage. Among them, the most noteworthy one is the car’s key fob not functioning properly.

If a Car Not Detecting Key Fob, it’s usually due to the reasons mentioned below;

  • Key fob malfunctioning
  • Key getting damaged
  • Problems with the break switch
  • Environmental influences

A swift diagnosis can easily help identify the issue. Furthermore, the solutions are relatively straightforward. However, you can also start the vehicle without a key fob if you’re in a pinch.

5 Common Reasons why is my key fob not detected

Car Not Detecting Key Fob

Continuous and rough use of your car can cause it to pick up various problems over time. Among them, its inability to detect the key fob is the most noticeable one.

The vehicle’s inability to detect the key fob can cause many problems, including not getting the ignition or the doors not locking correctly. However, there’s no need to panic as the solutions are quick and inexpensive.

Below are some of the most prominent reasons why your car might not detect the key. Keep on reading which problem might suit your conditions best and quickly discover the right solution.

1. Issues with The Key Fob

Understanding the nature of the key fob is paramount to figuring out why your vehicle isn’t detecting it. These devices are powered by electricity and wirelessly signal the car’s doors and help the vehicle be aware of its presence.

One of the main reasons the key fob may not be working properly is its battery becoming low. A lack of energy can cause it to send out signals inconsistently. Therefore, it becomes more difficult for the car to detect it or for the doors to work.

Another probable reason for the car not to detect the key fob is if the device’s battery dies. Although such an issue is a rare case, it can cause the product to become completely useless.

2. Key Becoming Damaged

Damage to the key can also cause it not to work correctly and send signals to the car. Continuously dropping or washing it without taking appropriate precautions can cause its inner technology to malfunction and even harm the metallic portion.

3. Car Parts Underperforming

Depreciation in certain parts of the car can also cause it not to detect the key fob. Among them, the most significant is the battery’s weakening, which can cause the vehicle’s immobilizer to underperform.

Other parts that can cause your car not to detect the key are the brake switch and the start button. If the brake switch isn’t properly positioned, the vehicle will not start. Press it firmly to understand if you have this issue.

On the other hand, your car may not start properly if the start button is defective. Typically, this phenomenon can occur if it doesn’t contact the vehicle when the user pushes it.

4. Technical Systems Malfunctioning

Although chances are slim, your car might not be able to detect the key due to an issue with your immobilizer module. This scenario usually arises if you drive through rough terrain or during harsh weather conditions.

Water damage, circuit board damage, and software issues are the main reasons why your car’s immobilizer may not work properly. Furthermore, faulty wiring and wrong antenna positioning can also cause the key fob to not emit signals properly.

5. Environmental Conditions

Your car’s location can be a possible reason why it isn’t detecting the key fob. If it’s in a place with alarms and radars, then it might be difficult to locate the key’s signal.

Such a scenario usually happens if the surrounding devices are emitting signals at a frequency similar to the one emitted by the key fob. You will need to get closer to the car to resolve this issue.

How to Diagnose Why Your Car Isn’t Detecting the Key?

It’s impossible to naturally start a car if it doesn’t detect the key. However, it might provide a range of signals depending on the reason why the vehicle can’t detect it.

Out of the many signs, the most obvious one is the no i-key detected prompt in the vehicle. Typically, it’s also followed by the car showing readings of not reading the key or not getting a signal from it. 

Sometimes, the key fob might provide you with signs of why the car isn’t detecting it. Among them, the most notable one is the change battery prompt lighting up on it. Another noteworthy one is the system error signal.

How to Start a Car Without a Key Fob?

Many people don’t know this, but they can start their car even if their key fob isn’t working wirelessly. The process depends according to the brand and model.

Drivers can start their car by pushing the start button with the key fob. Some start by placing it on the armrest bin. Other models might require you to unlock the key fob before pressing it to the start button.

Frequently asked questions (FAQs)

1. How long does a key fob battery last?

It should last 3-4 years.

2. Can I replace the key fob battery myself?

Yes, you can, the process is quite simple.

3. How much does a car key fob battery cost?

On average, 10 USD for one battery.


Many novice drivers start to panic when their car not detecting key fob.

However, the solution in most cases is a hassle-free and quick one. In most cases, all that the key fob requires is a battery change and it will be alright.

Unlike most car troubles, issues with the car fob have inexpensive solutions. Furthermore, you can bypass the problem by manually starting the car as well.

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