Originally Posted by las
Does it have a chip in the key?

Our Expedition does exactly that with one of the keys, which is now retired as a starter key. The chip went bad. We keep it on our person when traveling as a spare door opener in case we lock the real keys inside. Been known to happen....

frown. And it went bad just like THAT- overnight you might say. One day it worked, the next it did not.

But it sounds like water...
Many cars are designed to start momentarily then quit if the chip doesn't work. Some keys have batteries, too (like my Ram). If that's the case and the battery's dead, it will start momentarily then quit.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.