I need to replace my ECU, and I'm looking for the easiest option. I have a used ECU/DME, key assembly and key that all match. I see two options that seem to be the easiest in this order. For both I would swap the ECU/DME. The easiest thing would be to buy a new blank and use the matching fob with the blank cut to match the existing key socket. The second choice would be to replace the whole key assembly with the matching one. For the latter I have no idea where to start to remove the existing key assembly. Is that difficult? Any other options?

 

In order to use the used DME you have, you'll need a shop or dealer with a PST2 or PIWIS computer (with current PIWIS subscription) and access to both your cars as well as the donor's cars IPASS codes (VIN required on the donor car, proof of ownership required on your car). The Porsche ONLY accessible IPASS codes are required in order to program the used DME to your alarm modules immobilizer code. Without following this procedure your car will not start. It will crank but fuel and spark will be disabled unless the immo codes match.

Another option. Provided they are all of the same DME version and is correct for your model year car (including map): If you had the donor car's alarm module in addition to the DME, you could swap your DME and alarm module with the donor cars and the donor cars keys would both unlock the car and start/run it.

 

Maybe I've got my nomenclature mixed up. I have the unit that goes behind the rear seat, the unit under the front seat, the "Y" shaped key assembly and the key, all from the donor car. Do I still need the dealer to program the units?

 

The car should run if you replace the DME (behind rear seat), alarm module (under drivers seat), and use the remote key transponder from that car. You would have to swap your key into the donor remote fob (easy to do).

The above will work provided the DME and alarm module are from the same version and model car. If they are from a different year or model car they might not work without reprogramming at a dealer or shop.

 

I agree with Logray, however dme/ecu will not match the Vin of your car unless reprogrammed and do not throw out your old key to get into the car now because the new ignition key will not fit/work in the door lock or glove box.

 

The VIN# does not need to match, the field in the DME is just for informational purposes. In fact, most of the fields are just for information aside from the map, immo code, and dme code.

You can just transfer your key blade into the donor fob, and it should work like normal.

 

Logray Sorry for not being clear ....I agree car will run fine because of Ipas however if "fussy" will not read out proper Vin of car in Pwis? And yes transferring the key into fob should work but how will it open the door when fob is dead and the key only matches the ignition and not the door lock and glove box or am I missing something? I recall changing the door lock also but got lazy with the center glove box.

 

Yep the VIN will display different if you read it out from any computer, but the car doesn't need that to run. You can put in anything. XYZ121334234 and it will still run. In fact most of the fields you can put in whatever or even blank in some cases.

He doesn't need to transfer the locks, he can keep using his key blade. His blade will operate the door, glove box, etc. with or without the correct alarm module or even key fob (in fact sometimes I carry around a spare blade without the fob part for emergency purposes). That key won't start the car mind you, unless the fob is close enough to the ignition for the transponder pill signal to be received. (and then on to say that the transponder pill code must match and be programmed in the alarm module, which must have a matching DME and immo code with the DME in order for fuel and spark to not be disabled).

The transponder pill and remote code lives in the key fob. And those will (should already) match what is in the donor car's alarm module (assuming they were working in the donor car).

 

You right my Bad as long as the pill is there... everything good.

 

Thanks guys. Great discussion. I'll swap the DME, immo and blade. I won't mess around with the key tree.

What's the best way to take the blade out to minimize damage to the fob?

 

After you pry the FOB cover off. Use a small pick or screwdriver to hold the spring loaded plastic piston back, then the key blade should slide right out.

 

Everything works as advertised. Thanks. One more question. When I opened the fobs, each had a little capsule shaped glossy thing next to the blade. Is this what is referred to as the "pill?" Can I swap this as well, so I can use my original fob, so I can operate the remote locking function of the original fob?

 

Yes, that is called the Pill and needs to accompany your blade and Fob.

 

I have a question about how the key fob works. I swapped the blade to the donor fob and it works fine, but the remote buttons do not work. The donor is from a coupe so it has a three buttons where mine is a cab and only has two buttons. On top of that, the door lock button on the donor fob is broken. The pill has a copper wire sticking out of it. Is that connected to anything, or can I pull that out without damaging it? Does the transmitter have to match the pill? I tried to swap the transmitter portion only and it doesn't work.

So, I am to the place where the car starts, but the remote doesn't work. is there something I can do with the original and donor fobs to get the remote to work?

 

The coding is slightly different IIRC between coupe and cab, so more than likely you would need access to a PST2 or PIWIS to do that programming. At that time, they could also reprogram your donor alarm module to work with your existing fob.

The pill should not have anything sticking out of it as far as I remember. It can be removed as well and transferred, it's worth a shot if you want to give it a try. The car may not start though without the correct transponder pill.

If you already put in the donor alarm/immo module and the donor fob does not operate any functions on your car, then unfortunately there is nothing more you can do but go somewhere that has a computer to reprogram what you've got.