Wheeldog you are correct the FAST key does have a physical key that can be used in emergencies. I forgot about that. I seem to remember from the owners manual there are specific steps you have to go through to make the physical key work.

 

You might have read a section on getting a replacement or additional physical key, the key that comes with the car works.

 

After changing the FASTkey battery a few days later I got the beeping again, unfortunately I am too quick when exiting the door to see what the dash says so after a few times (it only beeps radomly) I managed to catch it again tonite and it read CHECK DOOR with a spanner. Any ideas what this means?

 

I have an 08 XLS. Last night for the first time, my Fast key didn't work and the engine wouldn't start because I couldn't turn the ignition switch all the way on, as if it was locked. Having read the manual, I removed the emergency key from the Fast key fob and tried it. The key turned the ignition switch all the way on, but would not start the engine. I had a friend jump the battery, but no luck, not even a click. I decided to find another ride home, I put the dummy key back in the ignition switch and tried it one last time, then it started right up!

I reread the manual today and found that you have to have the Fast key fob attached to the end of the emergency key if you are using the emergency key to start the engine. I tried it this morning, and sure enough, it starts if you have the fob attached, but not with just the emergency key! I still don't know why I couldn't start the engine initially with the fast key in my pocket they way I always do. But it is working fine today.

I worry about being somewhere remote, and having the same thing happen. I can't find in the manual what happens if the battery in your Fast key gets low. I know it is supposed to show a battery low condition on the dash display, but what happens if it gets too low? Will the engine not start even with the emergency key and the fob attached? You would think that they would make it so that you could start it even with a dead Fast key battery in an emergency situation.

If anyone knows the answer to that, please post. Otherwise, we should all carry extra batteries just in case!

 

That doesn't happen to the old square fob, because they key itself is chipped, so it will work without the fob. It's a little clunky though. I think your new key+fob will work even without a battery, have you tried it? I think battery power is not necessary to use the key+fob to manually start the vehicle. All it needs is a close circuit with the chip in the fob.

Also, the way this new fob are designed, it looks like the key loop serves to hold the fob with your keychain? I was wondering how snug the key fits into the fob, since it look like the you could lose the fob if if gets snagged.