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6 Reasons Why Car Keys Stop Working

Have you ever gotten out of your car and started to head into a store or other destination only to have the key fob fail to work. Maybe you hit the lock button and see that nothing has happened? You stop, try again and…nothing. You probably walk back towards the vehicle to try again, and give up, manually locking the doors.

Why Car Keys Stop Working?

This is not an uncommon issue with car keys, and yet it is not the only way they might fail to work. There are also times when they won’t unlock the car, when they fit oddly in the locks or ignitions, and more. To understand why car keys stop working, you have to start with the types of keys in use and then look at why they, particularly, develop performance issues.

Keyless car key fob showing front and back with panel removed to show emergency key
Keyless car key fob showing front and back with panel removed to show emergency key

The Different Car Keys in Use Today

You probably know the “classic” style of car keys, which is simply a key that is used to manually lock and unlock the doors and trunk as well as starting the vehicle. While it seems as if this style is slowly disappearing, it is safe to say that anyone who owns a car dating to 1995 or earlier has this specific style of car keys.

Classic style of car keys

In the years after that, manufacturers began blending the traditional keys with “transponders”. These are the types of keys that will not work if there is something wrong with the transponder, and that is because a receiver in the car is not able to verify that the key is the valid key. The signals passing between transponder and receiver as just as important as the appropriately cut key.

This style of car keys has altered to today’s array of keyless remote options and push button ignitions – meaning you don’t need actual car keys to drive the vehicle, just the transponder or fob.

Car ignition cylinder

6 Reasons that Most Car Keys Fail to Operate Properly

Knowing the different types of car keys can help you to start to identify just why yours might be refusing to do their assigned jobs. Let’s work our way from the simplest to the more complex causes of car key failure.

  1. Broken and/or Damaged Locks

    One of the most common reasons that people need new car keys is because they have actually snapped off the stem of the key in a lock. In other words, the lock is probably not working properly and causes the key to break the moment turning pressure is applied. This is an old school sort of problem simply because most keys in modern cars don’t undergo those types of pressures thanks to key fobs.

    Yet, it still happens. To avoid problems, frequently maintain the locks with appropriate lubricants and keeping them free of dirt and debris. Switch from your usual to your spare key from time to time, too.

  2. The Key Itself Is Damaged

    This is the most obvious reason that a key stops working and it can be physical such as the key is bent or worn, but mechanical issues with modern key fobs can be to blame. Remember, they are little electronic gadgets and if you crush them, expose them to too much moisture or electrical impulses, they may cease to function. Dead batteries can actually even cause the electronic code to reset.

    In fact, worn out fob batteries are a major reason for people thinking something is wrong with their keyless remote system. You usually get some warning signs that this is about to occur, such as having to click a few times to open a door. If you notice this at all, then it is time to get those batteries replaced ASAP.

  3. You Are Using a Copied Key

    If you have gone to a locksmith and had a copy of a manual key made (or even one with a properly programmed transponder), that key may not work. Why? Because even a well-made copy may end up with flaws due to too much duplication. For instance, if you use a copy of a copy of a key to make a new key, that key may fail to work because there are just too many slight deviations from the original. Try to get copies made from a car’s original key rather than copies of copies, and so on.

  4. Ignition Cylinder Problems

    Whether a new or older style, a car key that is used to start the car may cease working if the cylinder it unlocks and turns is damaged. Just like the external locks on the car doors, the ignition is prone to wear and tear. If your key is fine when used to open the doors or trunk, yet fails to work with the ignition, it may be that the cylinder is to blame.

  5. Damage to the Key Fob

    As already mentioned, electronic car keys (those with fobs or keyless start) can encounter problems, too. While crushing them, dropping them in water or exposing them to other risks may cause them to malfunction, there are other issues that might affect the key fob.
    As a simple example, wiring inside of the tiny fobs can fray over time, and this can cause a failure in communication between the transponder in the fob and the receiver in the car. Of course, the receiver may also be to blame (and that is actually inside of the car). Typically, issues of this kind require the help of professional locksmiths.

  6. No Programming

    If you allow a key fob with a battery to go dead, it can lose its initial programming. This is because any key fob must be “paired” to the car it is meant to operate. However, if you acquire new keys or aftermarket keys, you must do that initial programming that tells the transponder and the car’s receiver that they are supposed to operate together.

If your car key stops working, and it is not for any of these issues, it’s time to get in touch with a skilled locksmith who can troubleshoot the problem and come up with a good solution.


Why Isn’t My Car Key Remote Working?

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