How To Change The Battery In Your Toyota Prius Key Fob

Learn the most effective way of Prius keyless entry battery replacement method

A Prius key fob is the smart version of an automobile key that allows a keyless entry into the vehicle. The latest technology used in automobiles helps detect the presence of the key nearby and allows seamless entry inside the vehicle.

Did you know: The reason behind inventing this smart key was various cases that reported the owner being locked out of the car, as they forgot the key inside while they stepped out.

This invention led to a push-button start system that allows the driver to start the engine without inserting the key inside the jack. However, if the key is inside the car, the system installed in the car will not allow it to get locked unless the key is in the car.

In this article, you can expect to learn about how to change the battery in the Prius key fob, which batteries would work best for you, what are the protective measures that you can take for the key, and what can you expect if you are visiting a dealership to get your battery changed.

We will also discuss various smart decisions that you can make if you are stranded with a dead Prius key.

5 Steps To Replace The Battery In A Prius Key Fob

Prius keys use a battery to function. Thus it will surely discharge after a certain timeline. Now the challenge is how you can change a Prius smart key battery. Opening up the Prius key is the major part of the process.

Here are the steps that you need to follow:

  1. Locate the sliding tab on the key, and it will be present on the end where the keyring is present.
  2. Once you locate the sliding tab, pull the spare manual key out in one swift motion.
  3. Once the spare manual key is pulled out, focus on the same tab and slide the back of the key to remove the casing of the Prius key.
  4. After removing the case, you will observe four tiny screws attached to the battery plate. Now carefully remove those four tiny screws from the base.
  5. Once the screws are removed, you can see the battery. Now carefully remove it from the key with the help of a screwdriver or anything small in size.
Major Tip: A magnetic screwdriver is recommended to remove the tiny screws and battery from the key. It will avoid any damage to the key parts, as they are quite expensive to get changed.

What Kind Of Battery Does A Prius Key Use?

The size of the battery for the Prius keys can be different. So make sure you check the size of the Prius key before ordering one for yourself. However, we do not recommend you buy the battery online unless you are super sure about the size of the battery.

Mostly the CR2032 and CR2016 fit well with most Prius keys, but the sizes might still differ depending upon the manufacturing of your vehicle.

Pro Tip: Always go for a multi-pack purchase; it is cost-efficient and easily stored in the glove compartment.

Major Consideration: Visit the Dealership if you are unsure about the size; they will use screwdrivers with high magnetic precision. It will avoid any unnecessary damage to the key, and once you are familiar with the battery size, you can also go online shopping in the future.

How Can We Protect Our Prius Key?

The only way to protect your Prius key is by purchasing a smart keyring with an in-built tracker and a beeper. It is an under $40 investment, and trust us, if you avoid this investment, you can end up spending $300 to $400 just to replace your lost key.

What Can You Expect While Replacing Your Prius Key At A Dealership?

Every invention is followed by its pros and cons, and a Prius key is not an exception. Replacing the key will go between $400 -$500, especially in the case of the Toyota Prius. Remember, you are not paying for that tiny thing in your hand, but a massive technology installed in it to make it smart.

The hardware alone is quite expensive for a Prius key, plus your key needs to be programmed from scratch at the dealership. The features like keyless entry inside the vehicle and the immobilizer chipset are being programmed there and then to match the system installed inside your car.

Note: In the dealership, you are paying for the hardware and the hours of labor spent in programming everything from scratch to make it compatible with your vehicle.

Pro Tip: You might end up spending hours at the dealership. Thus it is suggested to visit the dealership on a free day.

Steps To Follow At A Dealership

  • Do not forget to bring the vehicle to the dealership. Then, you can use the manual key to drive.
  • You might have another working key at home, do bring it to the dealership, or you will pay a huge amount to the dealership. If you do not have one, expect to spend an extra 30-60 minutes in the dealership as the programmer has to contact the manufacturer to know the override code.

It will take almost an hour of extra work and money. Moreover, in some cases, the whole system in the vehicle is replaced, which will just shoot the amount to another level.

  • Do not forget to make an appointment first.

Warning: Do not try to buy a Prius key replacement online at eBay; trust us, it is not the best idea.

Why Do You Need To Drop The Idea Of Buying The Key Fob Online?

Here is an idea, why don’t I buy the key fob online and get it programmed at the dealership?

If you are thinking this as well, stop that thought right now. Many trusted online platforms can be trusted to buy things online, but do not make this mistake in this case.

A key fob is a very high-tech piece of hardware, and you cannot expect it to work if you order it online. Many people have tried this stunt, and they have ended up with the wrong product.

Every model of a certain vehicle has a special key fob designed for it, and you might not know which key fob is the one your vehicle uses.

They might look the same, but that does not mean they have the same technology installed in them. It is quite possible that the key fob is not compatible with your car at all.

In the best scenario, even if you get the correct model and everything, there is a huge possibility that the key will not be programmable with your vehicle.

But, if you still want to buy this high-tech piece online, I will not stop you. I can provide you with important information that you can use to avoid any huge blunders. So here are some pointers that will be available on your key. You need to note them down and keep that information safe with you.

Make sure you note this information before you lose the keys. Otherwise, there is no way you can buy the key fob online.

So here are the pointers that we are looking for:

  • Model Number
  • FCC: Federal Communication Commission Number
  • IC: Manufacturer’s Universal Code

Once you start looking for the key fob online, make sure these numbers match your key fob. If it is a second-hand key fob, ask the seller to read these numbers to you. If these numbers do not match, there is no use sticking around, as there is no way this key would work for your vehicle.

Important Consideration: If you compare the dealership charges with the online charge, do not ignore the shipping charge and remember that the key purchased online might still need programming.

Some Smart Moves For The Time You Get Stranded Due To A Dead Battery

If the battery of your smart key dies while you are on the road, calm yourself down first. Your mind will not work efficiently if you are in a state of panic. You have read this article from the start, so you have got this.

As stated above, there is a manual key present in your smart key. You just need to slide the tab near the key ring in one swift motion, and voila, you are good to go. The tab might be a little stiff initially, so do not freak out if it feels stuck.

Your salesperson at the dealership might have taught you this while you made the purchase. In some models, there is also an extra battery that is present alongside the manual key.

It is not a full-fledged battery, and it is just enough for you to get inside the car and light that engine up so that you don’t get stranded. This way, you can book an appointment at the dealership and buy the replacement.

If you use the extra battery, you need to hold the fob quite close to the ignition button and then push start. Remember, this battery is not that strong; you need to put it close to the ignition; otherwise, it will not work.

Major Pointer: You might get locked out if you leave the key inside; mind you, the signal is not that strong for the car to detect it from a distance. It is only enough to start the car a maximum of 2 times.

This whole situation can be avoided, and you just need to form a discipline. First, keep an eye on the onboard screen present in your car. It provides you the information about the battery life of your Prius key. Make a replacement as soon as the car starts to indicate the warning sign.

Pro Tip: Always keep some extra batteries in your glove compartment if you don’t want to get locked out of your car.

Some Common Problems With The Prius Key Fob

Sometimes keys can give you nightmares, and in this section, we will be discussing a few of them to avoid those incidents in the future.

Here are some things that can cause huge problems for you:

  • Leaving the key fob inside while locking the door is one thing, but leaving the spare key inside as well can cause huge problems for you, especially when the battery dies.
  • Sometimes the ECU might not read the code generated by your key; thus, your engine might not start at all in this case. Thus you need to get your key fixed at the dealership that might cost you at least $200 to $400.
  • You cannot be careless with your key. Yes, smart keys are way better than standard ones, but that does not mean they are not damaged. It will result in severe malfunctions in the key, and ultimately it will stop working after some time.
  • The misplacement of the key can be dangerous. It can be stolen or misplaced. In this case, even if you manage to enter the car. You will not be able to start the engine at all.

You need to remember that you have to be extra careful when it comes to smart keys. They are a boon in many ways, but they also have their own curses.

Sometimes these incidents are just inevitable, but it is our responsibility to be prepared for these situations. Thus always keep your replacements in hand with you. Also, invest in good quality products, as that will ultimately help you get through these situations.

Care for your smart keys in the same manner as you will care for your car. As their replacements are as expensive as any part of your vehicle.

Frequently Asked Questions

Q1. How Long Will The Prius Key Work With A Low Battery Indication?

In case of the low battery indication, the Prius key can be expected to work for at least two years, but the key will have a full or medium battery that is expected to run at least six years.

The role of the key fob is just to transmit a signal that the system in the car detects to carry out the major functions. However, it is still suggested that you keep extra batteries with you to avoid any unfortunate incidents.

Q2. Do I Have To Reprogram My Key All Over Again If I Change Its Battery?

Yes, you have to get your key fob repeatedly reprogrammed even if you change the battery inside it. Once the battery is replaced, the key starts from the beginning, which means the program is formatted from the key.

Thus it needs to be set from the beginning. Next, the new battery needs to be connected to the system inside your car.

Q3. How Can I Reprogram My Key Fob By Myself?

To reprogram your key fob, you need to sit in the driver’s seat with the ignition key and the key fob in your hands. Next, make sure all the doors are closed. Now lock the doors and turn the ignition off. Now you need to repeat the steps with other key fobs and restart the process all over again.

Is The CR1632 The Same As CR2032?
The CR1632 and CR2032 are quite similar, but you cannot replace a CR1632 battery with a CR2032 one because the sizes of both batteries are quite different from each other.

The name indicates that the CR1632 battery is 16mm in size, and the CR2032 is 20mm in size. Thus, the capacities of each battery differ too. First, you need to figure out which battery works best for your key fob and then buy one.


A key fob is a really tiny thing that can cause major unfortunate incidents that can hurt your pocket really bad. Everybody makes mistakes. It might happen that you forgot to keep track of the battery; at that time, a manual key is your savior.

Remember to be a smart driver. Thus, you need to be aware of how the technology works; thus, you need to learn how to change your Prius key fob battery. However, it will help you make smart decisions rather than spending a huge amount of money later.

The tips and tricks suggested above do not involve any rocket science but are necessary to change the Prius key fob battery. They are quite easy to follow by a non-tech person.

Remember it is always better to invest in something useful like trackers and batteries rather than feeling sorry about yourself later.


Written by Kane Dan

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