Deleted. *NM*

A few years ago, my ignition key needed a new battery. I put a new one in, but the key buttons would no longer operate their function and the key light would stay on (and drain to dead). I removed the battery and the key still functions otherwise (manual lock/unlock and starts the car). My spare key acts similarly (battery also removed now). I have been manually locking and unlocking and starting the cars for a few years now (both sets of keys). Is it safe to assume that the transponder is still linked with the car's ECU since it starts the car?

I got a new key head, which includes a new internal electronic circuit board and a transponder. I combined the original bottom part of the key which includes the original transponder (and the metal cut key portion) and the new upper portion of the key head (which includes the push buttons and new circuit board). I did this so as not to have to remove & switch out the metal key and the transponder. The key assembly pushbutton light turns on and off when pushed (doesn't stay on), but does not operate the pushbutton functions. The key assembly still manually unlocks the doors and starts the car.

Is it possible that the key pushbutton functions have lost their link with the ECU even though the transponder still allows the car to start? Do I have to find a dealer to re-program the key(s)?


Thanks.

tony, the keys have two completely separate functions. first, there is an RFID "pill" that is part of the immobilizer system. second, there is a transmitter that locks/unlocks the doors and arms/disarms the alarm system. these two systems are independent of each other.

the RFID pill is passive. it has no power source per se. its antenna receives a coded message from the corresponding antenna near the key cylinder. by induction, it creates current in the pill which the chip uses to process the message and create a coded reply which is transmitted by the same tiny antenna.

the circuit board is powered by the battery and activated by the button press. it sends out a coded message to the car. it does not receive anything.

both of these systems must be "known" by the car's computer. so if you got a new circuit board, it must be introduced to the car.

there is nothing in the keys themselves that is programmed. they have permanent codes which must be programmed in the car's computer so that the car recognizes and accepts that key.

your car still recognizes the RFID pill but of course, not the new circuit board. this new board must be programmed in the car computer. i don't know the procedure for doing that but surely someone else here does.

let me know if my above explanation was not clear.

--
MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

The tiny surface mount switches on my circuit board died. Its pretty normal. So i got a new head assembly and moved over the metal key, the "pill" (RFID) and the circuit board. But first i repaired the circuit board, mostly putting new surface mount switches on it. That way it was an easy re-programming. I will send oyu the article i wrote for NNJR-PCA Porscheforus on this if you send me your email address. Maybe this will work for you.

The tiny switches are fussy, but i got it done.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

I will call my dealer for a programming appointment (and pricing. Yikes!).

.. but does require some work and soldering skill

Grant

gee-lenahan-at-gee-mail-dot-com

Hello Grant, I just sent a PM to you re: your procedures.

'01 boxster s, biarritz white/metropol blue, 123,456 smiles...

That's a great explanation from frogster!
For the keyless entry system, I hope you kept the little tag that has the codes.
This tag will be needed together with your car's IPASS codes and with the use of a PST-II or a PIWIS, the new remote can be programmed into the Central Locking Unit in your car.
Only dealers and large independent shops will have those computers so check with the shop first to see if they can program it.
If you don't have the tag that came with the new key head, it cannot be programmed in.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

... a tag that accompanies the new key head.
I'm just a little confused, and I kept what I think is that tag for 9 years, but may've tossed it recently.
At least it's not needed at the moment.

They don't give you the codes for the keys that come with the car. In theory you don't need them as the dealer programs the car to work with the transponders before delivery.

Edited 1 time(s). Last edit at 07/13/2022 06:30AM by Laz. (view changes)

Does anyone have a picture of what one of these tags looks like? Just wany to check
it with tags I have with my keys that have a 986.xxx.xxx.xx number and a bar code.

From back in the day when Carrera GT key heads were cheap. The needed code in question is the hex numbers on the bottom partially covered by the red.

That is what I got from the dealer attached to my keys. I'm glad I didn't
throw them away. Thx boxsterra.