Key fob BS

So, got car out of storage and the fob wouldn�t talk to the car anymore, so no remote opening or frunk/trunk open. Won�t communicate with alarm system yada yada. Switched battery, flipped it upside down, tried everything I�ve read online to re sync, no dice (02 boxster S). Everything I�ve read said take it to the dealer. Grudgingly made the appointment with sunset, who have been awful since right before the pandemic. Get here and I�m told that unless I have a code I need a new fob. Huh. So, $525 to have a fob that works. Not sure it was worth that much. Is this corrrect? btw I know this is the 996 forum�I used to have one and this is the more active forum�

Yes that is correct.. There is a 10 digit code that comes with each key FOB, without that code there is nothing a Dealer can do, even with PIWIS........

For what it's worth. My magically stopped one day. I too went to dealer and learned about thr $500 key. Opted to not get it. Then it starting working again a month later. No clue why. Then it stops. Then it works. Still no clue why. But not out $500.

Quotes source post: 19549891

lmfao. May the fates ever blow your way 😆

Unfortunately, there is no free lunch or get out of jail free option with Porsche keyfobs. In all fairness, my original 25 year old Porsche keys still open and start the '99 996, but the electronic board that is responsible for locking and unlocking the doors is toast. The only remedy is a new fob from the dealership at $500. I wish there were cheaper options. Even the best locksmith in our area can't replicate these keyfobs. My 1997 Ford F150 only costs me $2 for a replacement key at Walmart. My father's 2004 F150 has the newer transponder keys. Cost me $8 at Ace Hardware to cut the blade and $50 to match the new transponder to the truck. I ordered two "clickers" (i.e. old school fobs for locking and unlocking) on Amazon for the 2004 F150 for only $10 and was able to program to the truck myself. I wish I could say the same for modern Euro cars with fancy keyfobs.

There is an aftermarket fob that taps into the DME and replicates the functions. I ordered one but after removing the driver's seat and seeing the 757,000 tiny wires in the bundle going into the DME I decided I didn't have the testicular fortitude to find the correct wires and tap into them.

For a while the Carrera GT keyhead was cheaper than a standard 996 head, all though not by much, seems to not be the case now. I had replaced one failed head with a GT head a few years back, then two years ago that one also failed on me, which I was not very amused about. What sucks is since only the driver door has the physical key lock, if you just say screw it and don't keep at least one working fob you run a risk of getting totally locked out of the car if that single point has a problem. Wasn't aware there was any aftermarket options, all though wire surgery is no fun, what's the name of it?

I make it a point to use my spare key every month or so, so I have all keys working and communicating

Quotes source post: 19551118

https://www.bergvillfx.com/products/t-lock-keylessentry

Five years with no fob. Sure it would be nice. But I'd rather light $500 on fire than a pay a dealer to make a key for a 25 year old car.

Wow, honestly, the t lock does not look bad at all and I am strongly tempted as its half the price of a single replacement fob, thanks for bringing this up as I don't think I'd ever have found it otherwise lol. Just to throw more info into the pile on this thread, there was a user post in here last year where they had dug into the immobilizer more, they put together some good info on the git link below but hadn't figured out how to recover the programming code out of a working fob, doesn't seem like there's been progress since. https://github.com/bdm310/996-Immobilizer

Quotes source post: 19552427

If you haven't seen it, here is a link to the Installation Guide for the T-Lock. I was overwhelmed when I saw how many wires were in the bundle. It looks a lot easier in the PDF file.

Yea, I took a look, I have coop's oil temp gauge which required a tap in the DME loom behind the back seat, so not only deal with all the wires but also cram yourself into the back, with this you can at least take the seat out and take your time looking at everything lol. I'm still not in love with tapping wires since you're punching through insulation and touching the copper, obviously its generally fine, but any chance to introduce electrical gremlins is no fun also good luck asking a shop to help track down random electrical stuff if you've done taps in the area. I'd be curious if its easy to source the connector used on the immobilizer to make a pass through connection which would be less disruptive.

Quotes source posts: 19551029, 19552656

Too much heartache and financial loss associated with malfunctioning or damaged immobilizers in these cars to risk it IMHO. I'd say, just bite the bullet and buy the darn keyfob from your local Porsche dealership.

Former 996 owner / current 986 owner. This exact thing happened to me the other day. Went on a Sunday drive to a local cars and coffee event, came home, and the key stopped working. Had to get my other key. This isn't the first time it's happened. All of a sudden, it works. I don't understand why or how this happens.

You're not holding your mouth right...

I dropped my fob this spring and it works no more. Does the T-Lock work with the alarm? When I open the door with the key, I have to put the key in the ignition or the alarm goes off. Does the T-lock disable the alarm?

I don't have to rush to the ignition when unlocking with the key, so you may have a different issue there. The unit is tapping pin 35 (door lock cylinder close) and 15 (unprime door) according to the wiring diagram in the workshop manual.

Quotes source post: 19552677

I wish it was just a plug and play harness that goes between the existing connector and the DME. That would be easy.

Quotes source post: 19553076

That's what I would expect... and, a solid guarantee that it wouldn�t do any harm the alarm module.

Quotes source post: 19552656

Those ScotchLoc connectors are a deal breaker for me. Whether I see them in some type of 'kit' or something wired in a car on BaT, I'm not touching it.

Quotes source post: 19553182

Same. It's such a hack way to wire something

Quotes source post: 19549853

Where would said code be? scribbled on a business card tucked into the owners manual? Taped to the underside of the dash? Engraved on the chassis somewhere? I have a '99 996 and both fobs were a disaster when I got them. Changing batteries did nothing, so I know its the internal electronics. I'm not suffering without the remote lock; I just use the key itself. Curious about the mystery code, though.

Quotes source post: 19559381

The 10 digit codes for each key FOB is for "security" and is kept secret and is not available.. A new replacement key FOB will come with a paper tag with the new unique 10 digit code used to program it to the car using PIWIS...after the new replacement FOB has been programmed to the car what happens to the paper tag varies...but it can get thrown away, or attached to the repair order and put in the Dealership file ,or stapled to the owners manual for future use...there is no Official set procedure for the 10 digit code, but it is a Security issue...

I'll be honest. I rather just not lock the doors. If they want to steal a 25 year old car, so be it. They stil have to deal with the immobilizer handshake with the RFID pill to start the car. That said, many years ago, when one of my keys had the circuit board stop functioning, I got 3 new keyfobs and had them coded and 2 remain in envelopes. I don't lock the car when it's in the garage.

Its a mess, these fobs are almost 30 year old tech at this point, they probably use some flavor of keeloq and probably could fall to some of the keeloq attacks which were publicized in the late 2000s, best case scenario would be that the fob's original code could be recovered through either a side channel or crypto weakness (not just dumping it from the fob memory) after recording a bunch of its transmissions. This may help some who have "working" fobs which are out of sync and could just be re-synced, but the overall pool of used keyfobs for sale isn't going to be large enough to make this a durable cheap source of replacements. If the immobilizer firmware can be dumped and reversed it could be possible to build a diy fob which could correctly pair to the immobilizer, but anyone trying to sell these at any scale would need to clear them through the FCC and maybe have Porsche be unhappy with them. This is all just for the remote unlocking component, the rfid pill for starting the car should basically be fine forever and you can transfer it from keyhead to keyhead. The tlock approach of strapping on an entire standalone box to do the remote unlock part seems like the only path to cheap fobs, but the wire splicing does not spark joy. A cool product would be a watertight box for the immobilizer which terminates the connections outside of the box and passes them to the immobilizer so you don't have to play the sealant game, and also integrates a standalone fob receiver.