How To Fix A Cars Central Locking

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Central locking in cars and other vehicles are a standard feature in most models on the market today. With just the push of a button, you can lock or unlock all of the doors simultaneously either via a key fob or from within the vehicle. Still, the central locking system faces its fair share of problems that can require a bit of know-how to resolve.

The method to fix a car’s central locking depends on the specific problem. This might mean replacing a faulty key fob or its dead battery, or a blown fuse which you can replace yourself. You might need a professional to help you replace a failed solenoid or broken wires.

This article will explore how to repair a car’s central locking based on the most common faults that cause it to fail.

Why Your Car’s Central Locking Fails (And How To Fix It)

Here are common reasons why your car’s central locking fails and how you can fix it.

Dead Key Fob Battery

Your car’s key fob is designed to give you keyless entry into the vehicle. The remote key works with the push of a button to remotely trigger the central locking system and open a locked door. They don’t use much power, so they typically rely on small batteries to stay powered. 

These batteries will lose their charge over time meaning they can no longer power the key fob. If the battery is dead, there’s nothing wrong with your vehicle’s central locking, but the remote doesn’t have enough power to trigger the system to lock or unlock the doors.

To resolve this, you’ll have to replace the dead battery. Using a small screwdriver, unscrew and open it to see what battery it’s currently using. Purchase a similar battery and use it as a replacement.

Faulty Key Fob

The key fob functions thanks to a small circuit board inside that transmits a signal to your central locking system whenever you press a button. If that circuit board is faulty, it won’t be able to send signals and communicate with the system or the door switches connected to it.

If you have a problematic key fob that’s preventing access to your vehicle, you’ll need to replace it entirely. A locksmith can duplicate the key fobs on some car makes and models. Others, however, can only be purchased from the manufacturer or one of their dealerships.

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Blown Fuse

Central locking systems lock and unlock all of your car’s doors simultaneously. So, if you find that it only works on one door’s lock switch but not the rest, you may have one or more blown fuses.

Fuses are sacrificial devices that blow to protect the rest of the central locking system. So, for example, fuses will blow when there’s a sudden electrical surge, thereby protecting the rest of the system from damage.

If that has happened and your central locking system only works on some doors but not others, all you have to do is replace the fuse. 

To do this, locate your car’s fuse box and identify the ones related to your car’s central locking system. Refer to your car owner’s manual if you’re not sure where the box is located.

Once you’ve found and opened the box, you can then identify damaged fuses by the burn marks on them or the burnt smell coming off of them. Remove the burnt fuses and replace them.

Failed Solenoid

When you press the button on the key fob to activate the car’s central locking system, the component that locks or unlocks the car door is known as a solenoid (or, in some cases, a door lock actuator). If your lock system works on some doors but not others, it’s possible that the solenoids for those doors have failed.

Replacing failed solenoids can be labour-intensive, as it involves removing the car door panel under the windows to access and service the solenoid. While you could do this as a DIY job at home with the proper knowledge and tools, it might be better to have a mechanic repair this for you.

Broken Wires

Your car’s central locking system consists of several components that require power to function correctly. Connecting each of those components is its wiring that delivers power when necessary to activate the door lock mechanism.

If the lock system has a broken wire, the system will not function correctly because the components aren’t receiving power when they’re supposed to.

Locating and fixing broken wires can be pretty challenging. That’s because it requires opening up the door’s panels and inspecting every inch of those wires before replacing or splicing the broken wires together again.

If you’re accustomed to working on your car’s electrical system and its wiring, then it’s possible to perform this repair yourself. However, if you’re not, it is safer and easier for you to let a qualified mechanic do it for you. The added cost will be worth it, as the mechanic can diagnose and service the wiring easily and safely.