Car Door Won't Lock with Key: Common Reasons and Ways to Fix

One day, you park your car in a shopping mall. As you ready yourself to go grocery shopping, you realize something - you left your car unlocked. You return and hit the knob on your car key. But much to your dismay, you don't hear any sound.

Opening the doors confirms your worst suspicions - your car key isn't working! You decide to risk it and go shopping. When you return, your car is luckily still there. But what about next time? If you're looking for solutions to car key issues, you've come to the right place.

We prepared to teach you the following about a car whose key dob doesn't work:

• What happens when it stops working
• Why it stops working
• What you can do to fix the issue
• How expensive the fixes are

What happens when your car door won't lock with a key?

Although a faulty key fob won't affect your car's performance, it can compromise its safety. After all, an unlocked car is an easy pick for thieves. But before we deal with the potential fixes, let's first examine the symptoms.

Firstly, you should start by assessing the problem. Is it just one door that won't lock? Or is it all of them? You can lock most cars manually by pressing a button on one of the doors. Is it only the key fob that doesn't work or are you unable to lock your car altogether? Can you hear the locking sound or not? A thorough examination will help you understand the cause behind your lock issues better.

While you have this issue, make sure you don't leave your car alone. You can still drive it, just make sure someone stays behind to prevent potential thieves from getting any ideas.

7 reasons why your car door won't lock - and how to solve them

Now that you know what to expect from a malfunctioning car key, it's time to look at the possible causes. Once you understand why your car won't lock, fixing it will be much easier. While some of the causes are easy to fix, you may need a professional mechanic to deal with others.

Here are 7 common reasons why your car door won't lock:

1) Your key fob's battery died

This may sound trivial but it's one of the most common reasons why your car door won't lock. Every key fob runs on a battery. Once it runs out of juice, you won't be able to lock your car. Even worse, you won't be able to unlock it either!

While key fob batteries can last for a long time, they will run out eventually. One way to check if it's a battery problem is to try to both lock and unlock your car with the key. If neither one works, it's most likely a dead battery. Check whether you can lock and unlock your car manually to rule out other issues.

Solution:

Simply replace your key fob's battery to fix the issue.

2) Your key fob is damaged or incompatible

If the battery seems to be just fine, the issue may lie with your key fob itself. This can happen if you're a bit rough with it. Over time, wear and tear can damage its components. It may also happen if you just bought a new car. Sometimes, the manufacturer may forget to program the key fob properly.

This is also common if you just bought an extra key fob. Your fob may simply be incompatible with your car. Make sure you check your manufacturer's manual for compatible models before you buy one.

Solution:

Unfortunately, you will need a professional to check and program your key fob for you. Contact your local locksmith to connect your new fob to your car.

3) Your car has blown a fuse

Sometimes, the issue may not be related to your key fob. Instead, the power lock may be to blame. High voltage can occasionally override the system, blowing the fuse in the process. When this happens, one or more of your car doors won't lock.

This means you may not be able to lock your car doors manually as well, which is even more dangerous. Makes sure you replace the blown fuse immediately to protect your vehicle from thieves.

Solution:

Luckily, you can fix this issue on your own. All you need to do is replace the blown fuse. They're easy to replace and don't cost very much. You can find the fuse under your glove box on the passenger's side. However, the exact location depends on the model. Check the manufacturer's manual to find out where exactly you can find it.

4) Your car has a damaged solenoid(s)

Solenoids are another part of your car's circuit. Each door has its own solenoid. If one of them goes bad, the associated door won't lock. You can spot this issue if it affects just some of your car doors.

Solution:

Replace the solenoid and check if the issue remains. You can find it under the door panel. Follow your manufacturer's manual to find the exact locations. Luckily, solenoids are relatively cheap.

5) The inner side of your car door is dirty

Although rare, dirt can sometimes get stuck between the door and the body of your car. If this happens, you won't be able to lock it. This usually affects just one or two doors.

Solution:

 Before you attempt any repairs, make sure you clean the inner rim of your car door. If you drive on dirt roads frequently, you should check on the state of your car doors every month. This should be more than enough to prevent the problem.

6) Your car door is damaged

If you can't lock your door manually either, your car door could be damaged. Mechanical damage can come with age. However, it may also be the result of an accident. If someone dented your car door recently, they may have damaged the lock system.

Solution:

Unfortunately, you will need a mechanic to fix this issue. The lock system is complex and you likely lack the tools and mechanical knowledge required to fix it.

7) Your car's wiring is damaged

Your car's lock system runs on electricity. Thus, it's connected to a series of wires. If they become frayed or loose, your car doors may not lock properly. Although this is rare, it can be extremely dangerous. Loose wires are a serious hazard and you should address them immediately.

Solution:

Much like with the previous issue, you should let a professional fix loose wires. They're hard to reach and tampering with them is very dangerous.

Is it expensive to fix a car door that won't lock?

It depends on the cause. If it's just a dead battery, you can fix it yourself. The same goes for a blown fuse or a solenoid, although these parts are a bit more expensive. But in most cases, you should be able to find them for under $100. You can usually replace this on your own, meaning you don't have to worry about labor costs.

However, the prices can skyrocket if you have a broken lock on a car door. The repair costs range from $200 to $600. Keep in mind that these numbers are rough estimates. The exact price depends on your location and vehicle mode.

Our final thoughts on a car door that won't lock with a key

A car door that won't lock is a serious issue. It leaves you more vulnerable to thieves. Even if you think no one goes checking other people's cars, you never know what could happen. If this happens to you, make sure you address the problem immediately.

The first step is determining if it affects just your key fob or manual locking as well. If it's just the fob, the problem could be as simple as having a bad battery. In this case, you can just replace it. Another common issue is a damaged fob. This happens due to natural wear and tear. It may also happen if your key fob fell on a hard surface recently.

Remember that your key fob needs to be programmed as well. If you bought an extra one, you should first visit a locksmith to get it tuned to your vehicle. Otherwise, your car won't respond to it.

If you can't lock your car doors in any way, it might be a circuit issue. Blown fuses, solenoids, or loose wires are all common. While you can replace fuses and solenoids, it's best to leave the wiring issues to a professional.

Another common reason why your car won't lock is due to dust and grime on the inner rim of your door. This is especially common if you leave in an area with a lot of dirt roads. Make sure you clean the edge regularly to prevent this. Mechanical damage may also be the cause, although this is much rarer.

When it comes to the cost of repairs, you can usually fix the issue for under $100.