Keyfob can start my car but unlock key does not work

It's just a stuck button, just use something to free it....like a small flat head screwdriver, exacto knife, toothpick

 

i'd be more concerned about not having a second key to begin with.

 

No. Not when the other buttons still work.
More likely that "gunk" has made it's way into the contact point. Skin oil will do that over time, often even if the protective rubber skin is intact.
A locksmith shop that deals with electronic locks might be able to get it going again......and get you a new case.
What about the second remote ??
Things are a LOT less complicated if that is present and working.
The time to get a second one if you don't have it is........while the first one is still working !!!

 

Buy a case, swap out the guts and the little chip. Good to go. It's less than $10.

 

Probably. Soak the contact points (easiest to do the whole board) in isoprophyl alcohol for a few minutes, without the battery in place, then blow it off with compressed air and let it sit overnight.

Like I said, a locksmith who sells the cases should be able to check that out for you too......at a small cost I think.

P.S. The "starting" function and the key functions are completely different electronics. They pretty much just share the battery.

 

Car starting chip is not powered on keyless models. Not sure on keyless models where you can keep key in pocket. The chip looks like a little grey weight in a separate area of the fob, separate from the lock unlock functions. Sticky switches could be cleaned easily enough. If not new board and chicken dance..

 

OOPS. True. RFID chips don't require external power.

 

90% is better for an immersion.
For a quick wash down, with a Qtip for example, either is OK.