Dadio

When in doubt read the owners manual. Wealth of information. For those too lazy to look it up, pg 299. You'll be amazed at how simple it is.

FoCo

Just received my 997.1 from the VA this Sunday and the battery was dead. We jump started it and found that the dome light was left on from its travels across the US. Next, the key remote would not function. Replaced the remote battery, no change. I put the key into the ignition, moved to it to the second position and held down the lock button on the key remote, the key flashed several times followed by a quick headlight flash. It worked. Thanks!

GrahamML

I had the same issue and also tried every iteration possible to get my keys to re-sync. The manual is not very helpful, but I finally stumbled on this approach, which worked great for me:

Lock the doors from the outside by using the key in the door lock.

Unlock the drivers side door using the key in the door lock.

Within about 10 seconds or so, open the door and insert the key into the ignition. DON'T START THE CAR!!

With the key still in the ignition, push the unlock button on the key.

Voila, you should be good to go.

177mph

Got two keys with my car. One working one dead. Replaced the battery following the procedure here on rennlist. Key lights up as intended.

Then followed all the procedures on rennlist and went thru owners manual. Nothing is working. Key unlocks the door - but then wont start the car. Followed every item to a T. Stuck.

I guess its off to the dealer.

Minok

The key's RFID signature needs to be added to the car's immobilizer system to authorize it to start the engine. I thought there was a process for that in the manual, but I recall seeing posts over the years where that doesn't work quite right all the time.

177mph

I went thru the manual and followed the procedures listed here. Nothings worked so far! Its frustrating.

SigAddict

This method fixed my key that would no longer lock or unlock my doors

Flyfishnick

I just had one key battery die a week or 2 ago and the other was already dead. Neither key would lock/unlock car. I did the "put the key in 2 spot in ignition and hold down the unlock button on the key until both the red dash alarm and the key were both flashing quite rapidly. Did that with both keys, everything works!!!!
1999

Engared

This works. 997.1 C4S 2006.

SF997S

Worked! Holy mackerel, thank you guys! I was initially furious about this when I heard people going to the dealer.