Are Key Fobs Waterproof? (This is the fix)


Forgetting to remove your key fob from your swimsuit pocket before leaping into the drink is a common holiday season error, and it has the ability to upset a really great day, but don’t panic. I’ll bet we can figure this out right now!

Key fobs are not waterproof. The traditional, machine-cut keys used in older vehicles can survive a submersible trip without harm. However, modern electronic keys such as the transponder key or smart key fobs are susceptible to water damage.

In this post, you’ll learn what to do if your fob gets wet and you’ll also learn the cost of replacing your key fob and what’s involved should the drying out method fails. Wet suit on, we’re going in!

Do Key Fobs Work When Wet?

Wet key fob

Key fobs don’t work when wet. You’ll need to dry your fob as soon as you find out you’ve gotten it wet. You’re more likely to lose your fob if you delay. When your fob comes in contact with water, it can suffer one or more problems:

  • It can lead to a short in the key fob’s circuit board since water makes a great conductor. Metal traces and other components on a wet circuit board will succumb to corrosion and rust also.
  • Wet circuit boards can also lead to a fob battery dumping its charge.

How to Fix a Wet Fob

The fob can be dried with a hairdryer or heat gun. To do this, disassemble the fob gently, although fobs are pretty tough, the internals isn’t. Using excessive force may make matters worse. If you don’t feel up to it, hire someone more skilled in DIY.

To open most fobs, use a fine screwdriver. On all fobs, you’ll find a special location, designed to pry apart the shells. A quick google of your model usually unravels the mystery.

Open key fob

Once the shell is open, remove the battery, this is important. Leaving the battery in risks shorting the fob and frying its circuit board.

Remove fob battery

Go ahead and remove all the plastic components, makes drying a ton easier. Use a hair dryer or heat gun to blow dry the electronic circuit and also the inside and the outside of the fob shells.

There are other methods to dry your fob. For instance, you can seal your fob in a container filled with raw rice for a while. The cereal will absorb water, even water that manages to get inside the fob. Fill some rice in a sealed container or use plastic wrap to let the rice work its magic.

This solution is recommended if you don’t want to go through the disassembly process.

Reassemble the Fob

Key fob circuit board

Before reassembling, make sure there’s no rust on the metal components, corrosion can set in quickly. Especially if your fab took a dip in the If you find corrosion, try using a dry new toothbrush to remove it.

If your fob’s battery has never been replaced before, take this opportunity to replace it with a new one. Seat the circuit board back in its locating dowels on the lower shell and place the top shell in place and squeeze together until you hear it click.

Then test on the car to see if it’s working properly. If it refuses to work, recheck your work and then try again. Placing the battery upside down is a common error.

If the fault persists, it means your fob is junk, hey it was worth a try. You’ll now need to ring the dealer and order a fob compatible with your vehicle. (more on this below)

How to protect key fob

If you have a waterproof case, you can hold your electronic key in your bathing suit strap while keeping your phone safe as well. Despite their splash-proof and floatation properties, these cases must not be submerged or subjected to prolonged water exposure. Doing so puts the contents at risk of severe water damage.

Where to Get a Key Fob?

Car Key

To replace your key fob (cars up to 5 years old) you’ll need to visit the dealer, special equipment is needed to program the new fob to the car, and so the car will need to be at the dealer’s workshop. That of course for some will mean a tow truck which is no doubt a royal pain in the ass.

Your Audi key fob must come from the company if you want one. This fob is equipped with a security chip that cannot be programmed for any other Audi. A new aftermarket key fob for Audi is not available online since it needs this chip. As long as the customers are aware of the risks involved, other retailers, such as Chrysler, Dodge, Jeep, and Lexus dealership, are not against programming aftermarket fobs.

New fob programming

Audi key fob replacements, including programming, cost about $500 on average. Generally speaking, this applies to all European cars, not just Audi. Because the manufacturer can only program the digital keys in a few select outlets across North America, you will almost always have to go through a dealer to get our locks.

Other retailers, including a Chrysler, Dodge, Jeep, and a Lexus dealership, don’t mind programming aftermarket fobs if that’s what you want them to do, as long as you understand the risks involved.

The Cost of a New Fob

The average cost for a new (or extra) key these days is between $150 and $500, and you’ll have to visit an auto dealer or locksmith to get one. In addition, the key won’t be a conventional metal key but rather a radio-controlled electronic fob that you can use to unlock motor doors and launch engines.

Key fobs might have some level of water resistance, but they are not waterproof. Follow this guide to protect your key fob or save it from the risk of water damage.

What to Do with Fob When Swimming

It’s an awkward problem, don’t want to leave them behind and don’t want to bring them with you. Anyway here’s a few simple solutions that work.

Magnetic box

Invest in a magnetic box that clings to your car’s chassis in a discrete location. The box is fitted with a combination lock, so all you need to carry is the info. Very James Bond!

Hide your keys under the car or near it

This is a great classic, but its execution depends on where you are and how many people are around when you hide your fob. There’s quite a bit of hiding space under or near a car, from the bumpers to the inside the wheels, over the tires in a chassis rail. It’s a simple solution, but be quick and discreet when hiding and retrieving your keys.

Use a waterproof pocket

A waterproof pocket allows you to take your keys safely into the soup. Just be sure it’s properly closed (watch out for the fold), I’ve seen some get caught out by this.

Now go ahead, enjoy that swim!

John Cunningham

John Cunningham is an Automotive Technician and writer on Rustyautos.com. I've been a mechanic for over twenty-five years, and I've worked for GM, Volvo, Volkswagen, Landrover, and Jaguar dealerships. My passion is cars. I use my knowledge and experience to write articles that help fellow gear-heads with all aspects of car ownership, including buying advice, maintenance, and troubleshooting.

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