If you can lock and unlock the doors of your vehicle using a physical key, then the locks are probably fine mechanically. However, there could still be an electrical problem. You can rule part of this out by locking and unlocking all of the doors via the physical master control inside the vehicle, which indicates that the electronics are fine.
Theres always a possibility that the receiver could be bad, or even disconnected but, its more likely that theres just an issue with your keyless entry remote. Most car key remotes use category 4 button cell batteries that arent expensive but it would still be a good idea to verify the actual battery your remote uses and check to see whether its condition is good or not.
There are a few ways to determine the type of battery you need. It may say in your manual, or you can contact a local dealer. You can also just open up the remote and look at the battery itself, which usually have a number written on it. Once you know what type of battery is in your remote, you can either check the voltage with a multimeter, or just swap it out with good one. Most of these batteries should show about 3 to 3.6 volts.
If your car key remote worked after replacing the battery, then youre done. If it didnt, then there could be another problem with the remote, like broken battery contacts or a problem with the buttons. Its also possible that your alarm system may have forgotten your fob, in which case you will need to reprogram it.
Key fobs are exposed to more physical abuse than most electronics, and they arent indestructible. The two most common points of failure are the battery terminal contacts and the buttons, although there are a lot of other ways they can break.
The best way to check this out on your own is to just pull the remote apart again and do a thorough visual inspection. If the battery connector terminals are broken, you should be able to tell by looking at them, and they may also feel loose. If they are, then carefully soldering them back in place may return your broken key fob to useful service.
If the battery terminals dont look broken, you may find an issue where the buttons are soldered in place. They may be soldered back in place as well, if you find that they have come loose, unless a button is physically snapped off.
The rubberized buttons used by most car key remotes can fail in a number of ways. If you notice that one or more of the buttons look like they arent popping back out correctly, or they seem to have come apart inside, that can prevent a car key remote from working properly.
In order for a car key remote to work in a secure manner, it has to be effectively paired with the receiver unit in your car. This prevents anyone with the same make and model from walking up and using their fob to unlock your car.
If your keyless entry remote and your car are no longer on speaking terms, you will have to reprogram your cars keyless entry system to regain your car key remote functionality. This is often accomplished by getting in your vehicle, closing the door, and inserting the keys in the ignition.
Rather than starting the vehicle, you will have to turn the key to the run position and back to the locked position several times in a row. If you turn the key to the start position, and the starter engages, youve turned it too far.
In the case that your vehicle uses that method of reprogramming, you will typically hear a chime after you have cycled the key several times. You can then press one of the lock or unlock buttons on the remote, after which you should hear the chime a second time.
Another method that some vehicles use is to get in the car and lock the door. You will then have to insert your key into the ignition and pull it back out six times within the span of 10 seconds. If your vehicle uses this method, and you succeed in doing it correctly, the exterior and interior lights will flash.
After the lights flash, you will have to insert your key and turn it to the accessory position, then push one button on your remote. If everything worked correctly, your hazards will flash.
There are other methods, and some require special equipment. In that case, you may have to contact your local dealer or an independent shop that has experience with your particular make and model of vehicle.
If you have an aftermarket car security system that included remote-controlled door locks in addition to an alarm, then you’ll need to check for any special reprogramming procedures associated with the system you purchased.
Replacing a Broken Car Key Remote
Keyless remote keychain fob held by a hand with illustration of lock icon on car door
If nothing else works, there is always a chance that the receiver inside your car is broken or disconnected. Youll probably have to take your car to a professional if you want to be absolutely sure that its working, however
The other option is to just buy a replacement remote, which you can obtain either new from your local dealer or used. If you buy a used one, you will have to reprogram your vehicle to recognize it before it will actually lock and unlock your doors. So if you discovered in an earlier step that your vehicle uses a remote that cant be easily reprogrammed at home, youll want to keep that in mind.
Used car key remotes are typically cheaper than new ones, but costs associated programming may outweigh the savings.