I recently purchased a 2016 F Type R, and didn't attach the Key Fob to my keychain. Naturally, I left it in my pants, and naturally, the wife put it in the washer.

I opened it up and dried it out. The battery was very low, so I put in a brand new one. The door lock functions work perfectly at range, the hatch opens normally at range, but the keyless start doesn't work unless I hold the key in the little slot for it left of the steering wheel that is there for you when your fob battery dies. Once the car starts, about 70% of the time I can put the key fob in the drink holder or wherever with no issues, though I have twice now been given messages while driving that the key fob is no longer in range.

The dealer wants $700 to replace the key, of course, because they have to replace the module as well, according to them. There are a few services on the internet that claim that if you send them the key module, they will return it with a new key for much less money, around $200 USD. Given that the key fob works, is there anything I can do or check to see why the remote start isn't working properly? Maybe i did something to it when I put the key back together that is shielding whatever it is that lets the car know that it is there?

 

It sounds like you only have the one key.
Is that all that came with the car?
Strange how many people seem to sell cars with only one.
Even though more expensive the dealer option presumably will give you back two new keys.
Better for you and better for then next owner.

 

Yes, only 1 key. And yes, that is getting to be more and more common these days. If a key fob gets damaged or broken, the cost to replace it is so high now, people just throw it away and live with only one. I wish car makers would make their fobs more robust so that they aren't so easily damaged in the first place. Pushing a button to start the car is cool, however in this case I'd rather have an old fashioned key...

 

And cooler when you spot the car's "beating heart" in the switch.

 

Used this procedure on an old flip phone years ago and recently a key fob for a 2021 Mazda 3 that got run through the washer.

1- Disassemble and remove battery.
2 - Soak in Deionized water (distilled will work if it's from a fresh unopened bottle). DO NOT USE TAP WATER. This removes any conductive soap or water soluble salts from the fob keypad and circuit board.
3- Wipe off excess water with a clean towel.
4 - Soak/agitate in a container of 99%-100% Isopropyl Alcohol. Must be at least 99%. Can be found on Amazon or at most hardware stores. This will displace any water in the fob after the water rinse. Unless the fob is made from unusual materials the fob should not be affected by the IPA
5- Wipe off excess IPA with clean towel.

Let sit in/on a warm place (like a radiator) to dry the unit for a day or two.

Note: This worked for me. YMMV. I run a research lab and DI water, 100% IPA and an exproof oven that could be set to 50C to dry the articles were readily available to me.