How to unlock the car if the key fob battery is dead?
This is the first question that comes to mind when you press the key fob button and nothing happens.
Although this is very inconvenient, there are a couple of things you can try and get yourself out of trouble.
Here, we’ll show the most popular and used ways. Besides this, you can watch a video tutorial on the same topic at the end of the article. You can also watch it on our YouTube channel.
1. CHANGE THE KEY FOB BATTERY
A dead key fob battery is by far the most common reason for this problem.
It’s normal for the battery to run out of power over time but perhaps this isn’t the main issue.
The main one is neglect. Although the key fob is a very important part of the car seldom do drivers change the battery on time.
Some even don’t know that a battery exists, mostly because they tend to last for years.
A sure sign that the battery is dead is when there’s no light coming from the little signal lamp on the fob (if there is one).
Besides this, when it’s totally depleted, the car will not react to the key fob at all.
If you’ve concluded that the key fob battery is dead, you have two options:
Replace it by yourself
On most key fobs this isn’t a problem. Most of them have pretty easy and user-friendly ways of doing this.
Also, if you’re lucky and all of this happened near a store or shopping mall, you can easily find the battery. With most key fobs, the batteries are standardized and cheap to buy.
A good option also is to have a spare battery around the car.
Take the key fob to a professional to replace the battery
Another way is to find a shop and let them do the job for you.
This is especially good if you’re not a fan of repairs and you’re lucky enough to find a shop nearby.
Specialized repair shops are of course the best choice.
But any kind of shop that repairs electronic appliances should be able to replace it. Just as long as they know how to open the key fob without damaging it.
2. UNLOCK THE DOOR MANUALLY
Know that almost all car manufacturers are obligated to have some sort of fail-safe system to open the car.
For instance, the problem doesn’t have to be the key fob battery. Sometimes the main car battery goes flat and all of the systems don’t work.
There are a couple of ways manufacturers have done this and it mostly depends on the type of key fob and locking system on the car.
The most obvious way is if you have a classic key fob with the metal key part fixed to it. All you have to do is stick the key into the lock and turn it.
In most cases, it’s a mechanical connection, independent of the electrics and electronics and you can open the driver’s door.
3. USE THE HIDDEN KEY INSIDE THE KEY FOB
Next most common way when talking about how to open the door when the key fob battery is dead.
If you have a key fob without a visible key part sticking from it, there’s a good chance that the metal part is hidden within the plastic fob housing.
This is done for aesthetic purposes and because of different, more modern start-stop systems.
So, you’re supposed to find the key and unlock the car with it.
The most common „gimmicks“ are:
Pulling the key out
The metal key part has a plastic handle which is an integrated part of the key fob. Sort of a holster for the key. So, find it and pull it out of the fob housing.
Opening the key fob housing.
In this case, you’ll find a small opening or slit on the housing. It’s meant, for instance, a screwdriver tip or for opening it with your finger.
Once it’s open, you’ll find the metal key part attached to the housing.
Again, these are the most common situations. It all depends on the type of car you drive. Best take a look at your driver’s manual or on the internet and inform yourself about the exact location.
4. OPEN THE PLASTIC LID ON THE DOOR HANDLE
But how to unlock your car if the key fob battery is dead and there’s a plastic lid on the door lock?
It’s easy when the door lock is visible. But on a lot of cars, because of aesthetics and because the manufacturer intended for the key fob to be used all the time, it’s covered.
Well, there is a gimmick here also.
The most popular one is to use the metal part of the key for taking the plastic lid off.
If you look on the lower side of the lock assembly, right beside the handle, you’ll find an opening that fits the key exactly.
You’re supposed to insert the key and use it as a lever to pull the plastic lid off. Once you do, it reveals a door lock and then the door can be opened like any other.
Again this is the most common option, there are different ways for different cars. As with the hidden key, best look up your user manual or Google it to inform yourself properly.
5. UNLOCK THE CAR REMOTELY
This convenient, high-tech feature is becoming ever more present on all cars.
If you have this user-friendly option, it pretty much trumps all of the other mentioned solutions provided that you have the app and that the cellphone battery isn’t dead.
With an installed app from the manufacturer (or some other emergency system), you can contact the manufacturer’s help center and they will unlock the car remotely.
I think we’ll be seeing more and more of this and hopefully, it will become a standard option for all cars.
6. TRY PRESSING THE KEY FOB FREQUENTLY A COUPLE OF TIMES
This one is worth trying if the key fob is for some reason damaged, like if it’s cracked or broken.
In these cases, the button on the housing can’t properly press the electronic switch or it may get stuck.
Pressing it a couple of times may cause a better contact, activate the key fob, and unlock the car.
7. TRY TO GET REALLY CLOSE TO THE CAR
As the battery in the fob depletes, the range of the transmitter weakens.
At the final phase, you really have to get close to the car, like a couple of inches or so, to be able to unlock it.
So, when the key fob doesn’t react, try getting closer to the car.
It’s even better if you know where the central locking unit is located in the car. You can go on that side and get even closer range.
8. WARM UP THE KEY FOB OR BATTERY
Batteries are sensitive to cold temperatures. The lower the temperature, the weaker the power.
This goes double if the key fob battery is on its last legs.
You have two options: either take the whole key fob or just the battery and try to warm them up.
If you have no other way, best put them between your hands or inside your jacket and hold or rub them.
This should produce enough heat to revive the battery if there’s any power left and make it possible to try and open the car.
9. USE THE SPARE KEY FOB
One more easy and logical solution, provided you have a spare key at hand or someone can bring it to you.
On this part, it’s good to mention that every driver should have a fully functional spare key fob available at all times.
Check the battery in it from time to time. Since they often stay unused, the battery may get drained.
Besides this, if some of the functions aren’t working, fix them as soon as possible.
10. CALL FOR HELP
When all of the mentioned options don’t work for some reason or you just don’t want to bother, use the phone and call for help.
Of course, first, call someone who can bring you the spare key. This is probably the least trouble and expense.
Another option is calling a tow service. This is maybe the most expensive solution and with the most fuss around it.
Calling some kind of mobile repair service or locksmith is perhaps best. When they hear what’s the problem and the car type, they probably already have a way to solve the problem.
If the malfunction is minor, like with a dead key fob battery, the repair will be done in minutes and it shouldn’t be that expensive.
So, you’ve seen all of these ways of how to unlock the car if the key fob battery is dead.
Most of them are easy, some of them work better while some are long shots.
But perhaps the best solution is prevention.
The moment you see that the key fob isn’t functioning properly or the working range is getting shorter, check out what’s wrong.
Sometimes fixing a faulty key fob isn’t cheap, but it’s certainly less than, for instance, having to tow your car and pay for the repair at a dealership or garage.
Also, have a spare key fob battery available around the car or in the household. They cost a couple of Euros or Dollars, don’t take much space but can be a lifesaver.
Make sure that the spare key fob is functional and you know where it is at all times.
All of these small and simple steps mean the difference between getting yourself out of trouble in a matter of minutes or standing helplessly next to the car for hours.
Written by: Sibin Spasojevic
Former car technician, life-long car and DIY enthusiast, author for Despairrepair.com
HOW TO UNLOCK THE CAR IF THE KEY FOB BATTERY IS DEAD? YOUTUBE VIDEO