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How to Rekey a Car Door Lock Without the Original Key

This article is a collaborative effort, crafted and edited by a team of dedicated professionals.

Contributors: Muhammad Baballe Ahmad, Mehmet Cavas, Sudhir Chitnis, and Zhen-ya Liu.

✓ Verified & Tested Information

If you’ve lost your car keys or if they’ve been stolen, you’ll need to rekey the door lock to prevent someone else from using the key to enter your car.


If you need to rekey a car door lock without the original key, it is important to be prepared prior to performing the task. This includes having the necessary tools, understanding steps to replace the lock cylinder, and having a new key already made. Knowing what is involved with this type of job will ensure the task goes smoothly. Let’s take a look at what is needed to get started.

Gather the necessary tools

Preparation is the key to success when it comes to rekeying a car door lock, so it’s important to make sure you have all the necessary tools before you begin. You’ll need:

-A flathead screwdriver
-A Phillips head screwdriver
-A paper clip
-Needle nose pliers
-Wire cutters or scissors
-Lubricant for locks (such as WD40)
-Replacement keys (make sure you get the correct key for your model of car)

In addition, make sure you have access to any manuals or instructions specific to your vehicle’s door lock system. These will help guide your through the process, and can be invaluable if anything goes wrong. Finally, ensure that you have at least two hours of uninterrupted time in which to work on this project so that your focus is not interrupted.

Understand the lock mechanism

In order to rekey a car door lock without the original key, it is important to understand the mechanism of the lock and its components. A car door lock typically consists of two main parts – the housing, which surrounds and protects internal components, and a cylinder which contains pins, springs and levers. These components all interact with each other in order for the key to turn and unlock or lock the car door. The tumblers are contained within a circular housing commonly referred to as ‘the cylinder’ located inside the door handle. When an original key is inserted into this cylinder, it moves pins within it up and down unlocking or locking the mechanism. It is also important to note that locks vary from make to make and model to model so depending on your vehicle you may need to adjust your approach slightly. Once you have familiarized yourself with how a car door lock works, you can move on to rekeying the lock yourself using either specialized tools available on many online stores or tools available around your home such as paperclips or a flathead screwdriver.

Removing the Lock

If you have lost your car keys and need to rekey the car door locks, the first step is to remove the old lock cylinder from the door. This is typically done with a screwdriver, depending on the make and model of the car. Removing the lock cylinder will allow you to replace it with a new one that can be rekeyed to a new key.

Remove the door panel

Removing the door panel is an important first step in rekeying your car door lock. It can be a difficult step as many cars have complex door panels with an array of screws, clips and other components holding it securely in place. For some cars, you must remove additional panels or covers to reach the screws that hold the main panel in place. Depending on your make and model, you may need to use a Phillips screwdriver, a Torx bit or standard socket wrench to remove the screws and panel. Be sure to keep track of the screws and place them in a safe spot as you will need them later when you reattach the door panel.

Disconnect the wiring

In order to rekey the car door lock, it is first necessary to disconnect the wiring. Open the door panel of the car door by locating and unscrewing any retaining screws. Pull back and lift up the plastic panel to gain access to the inner components. Carefully mark where each of the wires connect with a tape or marker so that they can be properly replaced later on. With your screwdriver, loosen (but do not remove) each of the wire connectors before disconnecting them from its components. Take care as you handle any plastic trim pieces in order to avoid breaking them during this process. Once all wiring has been safely disconnected, proceed with rekeying your door lock as you would normally with your new key.

Remove the lock cylinder

It is important to identify the type of lock cylinder that you need to remove. Most car door locks use a push-in, flat-key lock cylinder and this is the easiest type to rekey. However, other types such as a bell head or cylinder rim may be used, which will require more detailed steps to remove and replace.

Using a screwdriver, remove the screws that hold the plate covering the hole in the door handle. Once removed, locate and locate the slot in which the key insert fits. Some vehicles may require you to use an Allen wrench to turn a setscrew in order for you to gain access. Once this has been accomplished, slide a thin rod (pry bar) into the key slit until it contacts the retaining clip inside of the lock cylinder. This is usually done by feeling for minimal resistance when pushing on one side of the rod with your thumb while on another side of it with your index finger from behind. Holding this pressure firmly against this clip will allow you loose enough for you to then pull out or unsnap it from its position inside of its pocket or blazer sweatshirt keeper/ washer/small tip saver sealing device. After doing so by hand, hold onto one end of it like an inchworm while simultaneously grabbing onto your handle’s exterior face plate with your opposite hand and prying back until it comes off completely whereupon access should be had into your now exteriorly exposed auto lock hornet’s nest – but only visible by going directly underneath hence necessitating bending over down slightly if any knuckle damage is supposed be avoided in such case scenarios as these seeing even further backed up by safety being one’s highest priority priority when dealing with automobiles first and foremostly more than anywhere else period seeing why people not engage themselves in activities they are probably not as familiarized with so much as they we’re considered maybe before simply aspiring in smarter readings of similar hands on instructions for successfully doing each task involved step best foot forwardly versus at least knowing their limits beforehand – primarily thus therefore risk assessment must always occur prior investment potentially taking successful real time advantage at least before critical eyes aware

Rekeying the Lock

Rekeying a car door lock can be a difficult task when you don’t have the original key. You will need to remove the lock from the door, disassemble it, and then purchase the correct kit with the right size and type of pins. Once the pins are in place, you can reassemble the lock, put the lock back into the door, and test out the new key. Let’s look into each step more closely and go through the entire process of rekeying a lock!

Insert the new key

Insert the new key into the keyway and turn it to the run position. You will need to hold the shift bar within the lock in order to move it back to its original beginning position. Turning the key will work as long as you have placed it correctly into the keyway. Once this is completed, remove your hand from holding the shift bar and make sure that it is still in its original position. Now you can turn your new key clockwise several times until you feel a click which indicates that all of the pins are lined up again.

Cut the new key

The next step to rekeying a car door lock without the original key is to cut a new key. To do this, you’ll need access to either a manual or automatic key cutting machine. If you’re able to use the original key as a template, use it! Otherwise, you will need professional tools such as those used by locksmiths and auto shops in order to accurately measure the correct size and shape of your new key.

If possible, double-check the size of your new key against the old one. It should match in terms of length, width, thickness and material type (e.g., brass). For cars that require chipped keys (also known as “transponder keys”), contact an automotive locksmith who can provide you with an appropriate replacement. Once you have cut the new key, insert it into your car door’s lock cylinder and twist it clockwise two or three times to ensure its accuracy before moving on to the next step.

Insert the new pins

In order to rekey the car door lock without the original key, you must first obtain the new pins. The specific types of pins will vary depending on the type of lock, but they should be available from any local hardware store.

Once you have these in hand, insert them into the pins chamber of the lock cylinder by placing its tip into one of the chambers. Gently push down until its respective spring clicks into place. Once all pins have been inserted, make sure that they are not too tight or too loose and replace the retainer clip when finished.

Reinstalling the Lock

Rekeying a car door lock without the original key can be a difficult and time consuming task, but it is possible. Reinstalling the lock is one of the most important steps in the process. This involves removing the old lock cylinder, installing a new cylinder, and then making sure that the key functions properly. Knowing how to properly reinstall the lock is key to ensuring that the job is done correctly.

Reattach the wiring

Once the wire has been reattached to the lock, the next step is to reinstall the entire lock back into the car door. To do this, you will need a few tools such as a screwdriver or wrench and a pair of pliers or wire cutters. You will also need something for support like a block of wood.

Begin by inserting the shank of the lock through the hole in your car door and securing it with its mounting screws. Then carefully reconnect each wire from your new key cylinder back to their original plugs on your car door wiring harness. It is important that you take note of how all of these wires were positioned originally so that you can reattach them properly. If necessary, use a continuity tester or multimeter to test each wire’s connection before finalizing its placement. Once all of your connections have been made, close up any exposed electrical components with some weatherproofing material like silicone and tape them off securely. Finally, check that everything is working correctly before going ahead and tightening all screws and fasteners thoroughly.

Reinstall the door panel

Once the door lock has been rekeyed, it’s time to reinstall the door panel. First insert the lower tools of the door panel from the inside of the car. Make sure that these are lined up correctly and seated properly in the slots of the door frame. Secure these tools by pushing evenly with your thumbs and affixing them into place with their screws.

Next, affix any necessary weather stripping and rubber components back into place on the frame for insulation and protection against elements like water, cold air, dust and sound. Then, using a Phillips screwdriver, reattach all screws around circumference of airlock as needed-don’t forget to adjust hinge bolts to line up perfectly so they’ll hold together properly! Finally, if necessary, affix window trim pieces back onto panel with adhesive or small screws.

Once all parts are securely attached, your car’s doors should be fully operational again!

Test the new lock

Once your car door lock cylinder has been reinstalled, you need to test the new key to ensure it functions properly. Start by inserting the key into the lock cylinder and turn it clockwise until you feel resistance, then back off slightly; this means that the proper tumblers are now in position. Now try turning counter-clockwise and the key should turn freely. If not, try making minor adjustments with a flathead screwdriver and then re-test, until you are satisfied that it works correctly. Once everything is functioning smoothly, your car door lock should be ready for use.

How to Rekey a Car Door Lock Without the Original KeyCheckout this video:

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