What to Do When Car Key Falls into Water?

[MacPhoebe]

The solution when a car key falls into water is: 1. Stop using it immediately; 2. Wipe off the water on the surface of the key; 3. Use a screwdriver to open the key cover; 4. Remove the battery and wipe the circuit board; 5. Dry the circuit board and reassemble it. The car key is composed of a control system that includes three receivers: a transmitter, a remote central locking control module, and a driving authorization system control module, along with related wiring harnesses. Precautions for using car keys are: 1. Avoid contact with metal objects; 2. Do not place it near electronic devices; 3. Do not leave the spare key in the car; 4. Avoid throwing or dropping it carelessly.

[KatherineDella]

I remember one time when my car key fell into the swimming pool, and I was so frantic that I immediately jumped in to retrieve it. Electronic keys are most afraid of water because the circuit board inside can short-circuit and damage components upon contact with water. So, the first thing I did after fishing it out was to turn it off immediately—if the key has a button light, I pressed it to turn it off. Then, I opened the back cover of the key, removed the battery, and used dry tissue or cotton swabs to wipe off water droplets from the casing and button crevices. Avoid shaking it, as water might seep deeper inside. After handling it, I placed it in a bag of rice or in a ventilated area to dry for at least 24 hours. Rice can absorb moisture and help with drying. During the drying period, avoid using a hairdryer with hot air, as high temperatures can damage the plastic and chips. Once done, reinsert the battery and test the buttons—if the light turns on, it’s still usable. Usually, I recommend keeping a spare mechanical key in your bag for emergencies, so you can still drive temporarily if something goes wrong. If the key is completely broken, you’ll have to visit a 4S shop to get a new one or contact your insurance company—it might cost some money, but safety comes first.

[RhettMarie]

I'm quite skilled at disassembling car keys. When a friend dropped their key into a fish tank, I helped out. First, turn off the electronic functions to prevent water from causing a short circuit or corroding the metal contacts. After retrieving the key, quickly remove the back cover, take out the battery and internal circuit board. Rinse off surface dirt with water, but don't soak it for too long. Using isopropyl alcohol swabs to clean the contacts is most effective for removing stains. After drying, place it in a silica gel drying bag or a regular rice bag and seal it for two days—silica gel is more professional and absorbs moisture faster. Then reassemble the battery and test it. If the buttons don't respond, it might be a blown fuse or a damaged small component, which you can replace yourself if it's simple. The key is not to rush and use a heat source to dry it, as that can damage the plastic casing and cause deformation. A preventive measure is to use a waterproof sleeve for the key and avoid contact with water when outdoors. Keeping a spare physical key at home or the office is crucial for emergencies, so you don't have to travel far to find a repair shop.

[IvanRose]

I've experienced dropping my key in a puddle before, and I learned my lesson after dealing with it. Immediately retrieve it and power it off to prevent short circuits. Wipe the surface dry and leave it in a ventilated area to dry for a few days—don't rush to use it. Develop good habits: keep your keychain away from sinks or pockets when hanging it, or buy a waterproof key cover for peace of mind. Keep a spare mechanical key in your wallet or office drawer for emergencies, ensuring you can still travel if needed. If lost, contact the 4S store to replace the key—it's usually quick and reliable.