Imagine you are rushing to go to work and hop into your car. You insert the key in the ignition and try to start the car, but nothing happens. Soon you figure out that there’s something wrong with the keys. Sometimes the solution for such issues may be simple, but you must know the precise problem before troubleshooting. In this article, we have highlighted some of the common car key problems. So, read ahead to understand why your car keys are not working and what you can do to solve the issue.

Types of car keys

Before we get to the business end of the discussion, you need to know the different types of car keys. Because you need to know what kind of key your car has to figure out an appropriate solution. In this section, we explain the automotive key types.

1. Traditional keys

If you purchased your car long ago, it might have a traditional key that looks like any other regular key in your house. They are made out of a single length of metal with specific cuts/grooves to match the locking mechanism. This type of key can lock/unlock car doors and operate the ignition system. It is one of the simplest forms of keys in the automotive industry.

2. Transponder keys

It is the most common type of car key. It is a combination of a traditional key and a transmitter, which is attached to the physical key. The transmitter communicates with the receiver (vehicle’s ECU or Electronic Control Unit) to lock/unlock the car and operate the ignition system. 

3. Keyless fobs

The keyless fobs are the evolved form of the transponder keys. Usually, most premium cars come with a keyless entry system with a remote, also called the fob. The remote communicates with the vehicle via the ECU (similar to transponder keys) to lock/unlock the doors.

However, one of the major highlights of this type of key is the push-button start system. There’s no need for a physical key to switch on the ignition. You just need to carry the remote along with you to operate the ignition system.

Why do your car keys stop working? What can you do about it?

Now, you have a fair idea about the types of car keys. Hence, it will be easier for you to understand why automotive keys stop working and know the possible troubleshooting steps. Your car’s keys may stop working for various reasons, depending on the key type. In this section, let’s discuss the reasons for car key failure and troubleshooting options.

Traditional keys: Reasons for failure and how to troubleshoot?

There are two main reasons why a traditional car key stops working, which are listed below.

  • Damage to the key: One of the most common reasons for traditional car key failure is the damage to the key itself. Damage doesn’t mean that the key is broken into two pieces. It might be the slightest damage to the grooves or worn-out surface, which may not be visible. In such cases, the key’s grooves will not match the internal mechanism of the lock or ignition, and you will be unable to lock/unlock or switch on the ignition.


Often, the only solution in such situations is to create a new key. A locksmith will be able to do it for you with the help of your car’s key code. You can also contact your car’s service centre to check if they can provide a spare key.

  • Damage to the lock: If the lock mechanism itself gets damaged, you will not be able to lock/unlock the vehicle, even if the key is in perfect condition. In this scenario, either the lock cylinder is blocked/damaged, or there’s some issue with the lock assembly. If you can insert the key and turn it, then the lock assembly needs attention. Sometimes, dirt and debris can deposit and block the lock cylinder. In such cases, you will not be able to insert the key itself. Apart from that, if your car suffers a collision, the lock is likely to get damaged. The lock can also freeze in extremely cold temperatures. 


Troubleshooting this problem involves repairing the lock. If the lock is damaged beyond repair, you may have to replace the lock set and keys.

Transponder keys: Why they fail and how to troubleshoot?

Since transponder keys come with a physical key, they can also fail due to damage to the physical key, as mentioned in the above section. As mentioned earlier, they can also fail due to damage to the lock. Apart from that, there are a few more reasons for a transponder to fail. You can refer to the following points for the same.

  • Dead key fob batteries: The key fob or the remote uses batteries to operate. The batteries run out of juice after a certain period. The physical key may work in such a scenario, but the remote functions may stop working.


The simple way to troubleshoot the problem is to replace the dead batteries with new ones. After you change the batteries, the key fob should start working, provided there are no other issues.

  • Damage to the key fob: The key fob/remote comprises electronic components such as a chip, batteries, etc. If you damage the key fob by dropping it or exposing it to water, it may stop working. Apart from the transponder, if there’s an issue with the receiver inside the vehicle, the key fob may not work. If that happens, you will not be able to lock/unlock the doors or switch on the ignition.


In such a situation, you must take the key fob to the authorised service centre to diagnose and rectify the problem.

  • Using aftermarket keys: If you get an aftermarket key, it may not work with your vehicle because the receiver and the transponder are programmed to communicate with each other. The aftermarket key may not be programmed. Hence, it cannot communicate with the vehicle’s receiver.


In such situations, you can contact the authorised service centre to program the key fob, provided the service centre approves using such keys.

Keyless fobs: Why do they fail and how to troubleshoot?

Keyless fobs are the more advanced avatar of the transponder keys. However, the basic working principle of key fobs and transponders remains the same. If there’s any damage to the fob itself, it may cause damage to the internal electronics (chip), and it may stop working. The only difference here is that you cannot lock/unlock the car or turn on the ignition due to the absence of a physical key.


If you find yourself in such a situation, you can either get a spare fob from the authorised service centre or tow the car to the service centre to program a new fob to your vehicle. Please note that if you get a spare fob, remember to get it programmed for your car, or else it will not be of any use.

Other car-key-related problems and solutions

Apart from the reasons mentioned in the above sections, there may be a few other issues with the car key. This section highlights such car key problems and their possible solutions.

  • The car’s central locking is not working with the key: This problem may arise if the key fob has an issue or the fob’s battery is dead. You can try replacing the batteries or getting the key remote diagnosed at the service centre.
  • Car key sensor is not working: If the key is not working at all, it may be due to the drained battery, faulty fob, low car battery, or faulty keyless entry system (if applicable). You can try replacing the fob batteries, diagnosing the fob or towing the vehicle to a service centre to fix the issue. 
  • Car key not working in the ignition: If the key is working fine with the doors and doesn’t work when you insert it in the ignition, it may be a sign of a faulty ignition cylinder. You can get it checked at the service centre. The expert will let you know if it is repairable or needs replacing.
  • Keyless entry not working with the fob: This problem could be due to a drained fob battery, an issue with the fob, a faulty keyless entry system or a drained car battery. It’s a critical system; hence, you must visit the service centre to rectify the problem.
  • The car door lock is not working: The main reason for this problem could be a faulty lock mechanism. This issue could also occur if the key/fob is defective. You can try troubleshooting by checking the key/fob. If the troubleshooting doesn’t work, you can visit a car key locksmith or a service centre to fix the lock/key.

Frequently Asked Questions (FAQs)

Here are a few common questions and their answers related to situations where the car keys are not working.

Frequently Asked Questions (FAQs)

Car doors won’t open with the key fob. What should I do?

Check if the key fob battery is drained and replace it with new batteries. If that doesn’t work, get the fob inspected by the service centre. If none of the methods work, get the door locks checked at the service centre.Can I repair the remote?

You can get the key remote repaired, provided it is in a repairable condition. You may have to get a spare fob if it’s damaged beyond repair.Can I use an aftermarket key fob for my car?

You can use an aftermarket key fob, which is programmed to work with your vehicle. However, check with your service centre if it’s safe to do so.Can I turn on the car’s engine if the key fob is faulty?

Typically, you cannot turn on the car’s engine if the fob is faulty. Modern cars come with a security feature called Engine Immobiliser. It prevents the engine from starting until you use a correctly working key.What is a speed-sensing door lock in cars?

Speed-sensing door lock in cars is a system wherein the doors will lock automatically after the vehicle reaches a certain speed.What is impact-sensing auto door unlock in cars?

The impact-sensing auto door unlock is a safety feature wherein all doors will unlock if the impact sensors detect a collision or impact.What is a passive door lock and unlock in cars?

The passive door lock is a system wherein all doors will lock automatically after a few seconds after you switch off the ignition. The passive door unlock mechanism will automatically unlock the doors if you are near the vehicle with the key fob.What is delayed door lock in cars?

The delayed door lock is a feature which does not allow the doors to lock when one of the doors is still open. The system waits until all the doors are closed before locking all the doors.How can I fix the locking mechanism of the car door?

You cannot fix the car door’s locking mechanism by yourself. You must visit a locksmith or the car’s service centre to get it fixed.

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