My car key for my Toyota Camry was accidentally put through the washing machine and now no longer works. How can I fix this?
Sorry to say but you've probably fried the electronics in the key.
If you haven't already I recommend taking the fob apart (i.e. removing the battery) and placing it in a bag of rice for 24-48 hours to ensure it is fully dried out, you can then reassemble with a fresh battery and attempt to reprogram the fob to the car, if this doesn't work then the fob is likely toast and you'll need to replace it. You can either go through a main dealer to get a new one and have them code it to the car (this is likely to be rather expensive I'm afraid) or you can try buying a replacement off eBay or similar and try programming it yourself using the steps in the above link.