Are Car Keys Waterproof? [and What to Do When They Get Wet]

Let’s say you forgot to take your car keys out of your swimsuit pocket before you jumped in the pool, or maybe they fell into a puddle on a particularly rainy day. You might be wondering if your keys will still work or if they need immediate replacement. So, are car keys waterproof?

Like many electronics, car keys aren’t waterproof. While a traditional, machine-cut key used in older vehicles can survive an encounter with water unharmed, a newer electronic key like a transponder key, smart key (sometimes called a keyless entry device), or remote control key can be seriously damaged or even completely ruined if submerged.

If you still have questions, don't fret. In this guide, we'll discuss what to do if your keys get wet, how to replace them if needed, and more. Just keep reading!

Photo shoot of BMW 750Li, closeup shot of a start car key in a male hand.In the background is blue sea and sandy beach, Are Car Keys Waterproof? [And what to do when they get wet]

What Happens To Your Key Fob If It Gets Wet

If your key fob gets dropped into some water or you realize you forgot to take it out of your pants’ pocket before starting the washing machine, you must get it out of the water immediately. The longer the fob is submerged, the more likely it is that your fob won’t work anymore. You’ll likely have to buy a potentially-expensive replacement.

There are several ways your fob can be damaged. The problems begin once the circuit board inside the fob gets wet. Parts of the circuit board can get shorted out or rust and corrosion could set in faster. In more severe cases, the battery can die, leak, or explode.

What Do You Do If Your Key Fob Gets Wet?

Once you’ve immediately taken the fob out of the water, you have a couple of options. You can either try to repair it yourself or get a replacement. We’ll discuss both of those options in detail later in this post. It’s possible your car manufacturer hid a traditional mechanical key in the fob that you can use in the meantime.

Examine the fob for any catches or levers. If you see one, push it and then pull the mechanical key out of the fob. Once you’re inside your car, look for a plastic cap near the steering wheel. Remove it and you’ll see a key slot. We’ve already discussed unlocking and starting a keyless-entry car without a fob in our post: Lost Car Keys? Here's What To Do. So, read that if you want more information.

This method isn’t as convenient as a remote control or smart key. However, you’ll still be able to unlock and start your car until you decide whether or not you want to replace the fob.

How Do You Fix A Water Damaged Key Fob?

Close up of man unlocking his car on rainy weather.

As we’ve discussed, it’s always a risky proposition when your key fob gets wet. It’s best to exercise caution and prevent it from happening in the first place. However, if your fob does get wet, there may be a chance you can save it.

Step One

After you immediately take it out of the water, hold the fob button-side down. Shake it a bit to get as much water out from its interior as possible. Place the fob button-side down on top of a clean, dry towel or cloth and let it rest there for a few minutes. Then, use the towel or cloth to get as much water out of the crevices as you can.

Step Two

Next, you have to open up the fob since some water might have gotten inside it. Use the method we previously described to do so. Remove the battery and use a clean cloth to dry it, the fob’s interior, and the circuit board. If the battery is leaking or damaged, safely dispose of it and get a replacement. You might want to replace your battery even if there’s no visible damage since any serious contact with water can harm it.

Step Three

Dip a cotton swab in isopropyl alcohol and wipe down the circuit board and the fob’s interior to remove any battery acid residue or other contamination. Let all the parts sit until they’re completely dry. Then you can install the new battery and reassemble the fob.

Step Four

Test each button on the fob. If they all work, then the fob is good as new! Then, if some buttons work but not all, then repeat the cleaning process and test the fob again once you’ve finished. If none of the buttons work, you’ll either need to get the fob reprogrammed or replaced entirely.

Whatever you do, don’t try to dry your fob with either a hairdryer or a microwave. The former option will fry your key’s circuitry and ensure it never works again while the latter could start a fire. You should also know that even if you follow this method precisely, there’s still a chance your key won’t work anymore and you’ll need to buy a replacement.

How Do You Unlock A Car Key?

New Car keys in the ignition being programmed

If your car key fob gets drenched, you may have to open it up to see whether or not any water made it inside the device.

If your fob is secured with screws, use an appropriate Phillips head or flat-nose screwdriver to open it. And if your fob doesn’t have screws, use a flat-nose screwdriver or another small, flat object to gently pry it open. You should see a slot on your key fob intended for this purpose.

How Much Does A Key Fob Cost? 

The bad news is that as car key technology has progressed, replacement costs have dramatically increased. The good news is that you might be able to reduce or even avoid replacement costs altogether. This depends on your vehicle’s warranty, your car insurance policy, or if your new-car dealer covers lost or damaged fobs. 

However, as a general rule, it costs between $50 and $100 to get a replacement key fob. The cost of replacement also depends on the vehicle, the labor, and the type of key fob itself. 

Where Can You Program A Replacement Key Fob?

Man holding his car key fob, Are Car Keys Waterproof? [and What to Do When They Get Wet]

If you want to program a replacement key fob, you can head to your car dealer, a local mechanic, or try it yourself.

Car Dealer

Midsection of car saleswoman using digital tablet at dealership parking lot
Midsection of car saleswoman using digital tablet at dealership parking lot during daytime

It’s recommended you go to the dealer to buy a new fob if your car is less than five years old or made by a European manufacturer. You’ll need the dealer to program the fob’s encryption for these vehicles. The entire process can cost anywhere from $50-$500, depending on the brand.

If you want to save money by purchasing an aftermarket fob before bringing it to the dealer for programming, you can, but there are some risks involved. Some dealers refuse to work with an aftermarket fob while others will attempt to program it but can’t offer any warranties or guarantee it will work when they’re finished.

Local Mechanic

If your car is ten years old or older, it’s more likely you can get away with buying an aftermarket fob and hiring your local mechanic or an automotive locksmith to program it. Make sure you call them in advance to make sure they have the right equipment to program the fob for the type of vehicle you drive. Some shops are better-equipped than others. For instance, if your vehicle uses keyless entry, ask the mechanic if they can program those kinds of fobs.

If you have an older vehicle and your local mechanic can program your fob, then you might save some money compared to buying a new fob from your dealer. Some locksmiths might also offer to drive to your home or wherever your car is and perform the job there, saving you some time.


Alternatively, you could buy and program an aftermarket fob yourself and avoid hiring a locksmith. Just be sure to check whether or not there are easy-to-follow directions for doing so included with your purchase. Your car owner’s manual might have instructions for programming fobs for your vehicle. You’ll need two working fobs on hand to do this yourself, so this isn’t possible when you’re out of fobs.

In Closing

Lost Car Keys? Here's What to Do

Now you should have an understanding of why you should avoid getting your key fob wet, how you can unlock and start your car when you can’t use your fob, how you might be able to fix your fob yourself, and how much a new fob might cost you. The next time you have to fish your key fob out of the washing machine, don’t panic. You have options!

Before you go, be sure to check out these other articles that may be of interest:

Where To Get Car Keys Made?

11 Unique Gifts For Car Lovers

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