DME Replacement

[Paul Grainger]

What is involved in changing the DME in a 1999 C4 6-speed?

I have a replacement unit with the same part number, Durametric reports no fault codes but the car will not start because the replacement DME is not coded to the car.

What info do I need to have the replacement DME coded to my car?

Do I need any info from the donor vehicle? (VIN?)

Thanks

Paul G

[Mother]

You need at least the VIN from donor and your VIN. The key, alarm and DME must all match then have your local dealer program them, the car will need to be at there place to do this at least that is how it works here.

[Paul Grainger]

Are boxster and 996 DME's interchangeable?

I have obtained all the DME data from the proposed replacement DME unit via durametric, it seems that the DME unit that I have acquired was actually from a boxster, although it was sold to me as being from a 996 and the part number exactly matches my existing 996 unit.

From durametric:

The 'part numbers' differ only differ by one digit (ie 986 and 996), the rest of the 11 digit number is the same.

The 'supplier part numbers' are identical

I have the vin numbers from the donor and my own car

ID numbers are different (9964RDW01 / 986SRDW01)

order types are different (996411, 986321)

Software versions are diferent (004157026330 / 004157026730)

Will this ex-boxster DME work in my 996?

Paul G

[Richard Hamilton]

I'll start by saying that I have never done this, but I believe it is possible. There are 3 Secutity Codes for the car:

Immobiliser Code

Teaching Code

DME Programming Code

These are stored on Porsche's IPAS system, and they record the codes against the VIN number. I think you would need all the codes from yours and the donor car.

As I see it you would need to program the 'new' DME with the immobiliser code which matches the one in your existing alarm control module, and also program the 'new' DME with the correct fuel map for your car. When replacing the DME with a new one the routine is to read out the data from the old DME, replace it with the new one, and then program it to suit the engine, immobiliser, and catalytic converters. You also need someone with a PST2 who knows what they are doing! Todd Holyoak (tholyoak) has written several posts on the 986 forum about reprogramming DMEs for his 3.4 and 3.6 litre engine swaps. It would be worth you searching there for more info.

[tholyoak]

If the new DME is in fact new (never been programmed before), you only need the codes for your car from the dealer so you can transfer them to the new DME. If the DME is used, you need the codes from the old car and the new car so they can be replaced. The 986 and 996 of the same version (5.2.2, 7.2, 7.8) used the same DME, they are just programmed with different maps.

As Richard said, I have done this several times, and it works flawlessly.

Todd

[Paul Grainger]

Can the maps be read by a pst2 and transferred from one DME to another?

The IPAS codes can presumably be obtained by my dealer given that I have VIN codes for my car and the donor vehicle (the replacement DME is from a write-off car).

If the mapping in the donor DME is incorrect (given that it presumably came from a boxster), can the maps in my existing DME be copied across to the replacement unit?

Paul G

[tholyoak]

The maps needed are in the PST2, you don't copy maps from one DME to another, you select which map to flash the DME with. With your replacement Boxster DME, you will need to hook your 996 dme up to the pst2, and read out the data under the programming function. This allows you to select the correct maps. Then swap DMEs and program the Boxster dme with the 996 map, it is now a 996 dme

Many dealers will not give you the IPAS codes without proof of ownership. So having just he vin of the totaled car may not be enough. Other dealers are more lenient.

Todd

[Richard Hamilton]

If the donor DME came out of a Boxster, it will have the Boxster map. The PST2 is used to program the DME with the appropriate map. I am not sure if the maps are stored in the PST2 and transferred, or they are stored in the DME and activated by the PST2, but any DME can be programmed for any variant, provided it is the same DME version. In other words, you can program the Boxster DME to the 996 map and immobiliser codes, as Todd confirms.

Therefore if you can get all the codes from both the DMEs you have everything you need for someone who knows what they are doing with a PST2 to program the car. I would be interested to know how easy it is for you to get the codes from your dealer. Please let us know.

edit: beat me to it Todd!

Edited June 3, 2007 by Richard Hamilton

[Paul Grainger]

Thanks Richard and Todd for your replies.

I know that dealers are very reluctant to give out IPAS codes. I don't have a PST2 but my local dealer (specialist in Nottingham rather than main dealer) has the laptop based PST2 system and has easily got the IPAS code for my car in the past in order to programme new keys, this has been obtained from the VIN number from Porsche so I am hoping that they will be able to get the IPAS code for the replacement DME given that I have the VIN number from the donor vehicle. They will be doing the work (setting up the DME to suit my car) themselves so I hope that they will do this without too much difficulty.

Paul G

[cheetah]

Can the dealer make these changes by giving them both DME's, or do they need the car present?

I have a 2002 Boxster S that I am doing a 3.4L 7.8DME conversion into. I obviously have my original DME and also have a 7.8 DME sitting here that I bought with all of its codes / numbers on a piece of paper.

The dealer said that they will help me flash it (as I bought the engine from them), but I would prefer not to have to tow the car to them just to flash it. Or is there a way to allow the car to ignore the immobilizer and get it to the dealer that way?

Any help is appreciated, as I will hopefully be to that point in a few weeks that the car will be ready to be driven again!

Thanks,

[logray]

...If the new DME is in fact new (never been programmed before), you only need the codes for your car from the dealer so you can transfer them to the new DME. If the DME is used, you need the codes from the old car and the new car so they can be replaced. The 986 and 996 of the same version (5.2.2, 7.2, 7.8) used the same DME, they are just programmed with different maps. As Richard said, I have done this several times, and it works flawlessly...

Since you've done this before, can you help me with the procedure? I have a replacement DME and a PST2. I have all of the codes for my VIN and current DME. I have the VIN for the replacement DME, but no codes. I haven't tried programming the replacement yet.

I can't work out why you say when programming a "never programmed unit", one would only need codes for the existing "OLD" DME.

Looking at the WSM the procedure asks for an "old" code even for a brand new unit I assume. Are you saying a brand new DME would in theory have no code and therefore when the PST2 asks for the "NEW" programming code you put in nothing there? Or perhaps a NEW unit comes with it's own DME programming code?

And this is the reason why with a USED previously programmed DME, one would need the "old" DME programming code?, which actually becomes the "NEW" DME code in this procedure, if that makes any sense. And then your existing DME would become the "OLD" dme code in this case.

Looking at the WSM (paraphrased), it says to do the following with PST2 on a BRAND NEW DME.

1.) read control unit

2.) install dme module

3.) select program control unit

4.) ensure requirements requested are fulfilled

5.) input VIN & confirm

6.) input OLD DME code & confirm (your existing DME's code?)

7.) input NEW DME code & confirm (on a new DME, does it come with a code or would this just be "blank"? I guess on a used DME, this would be the used DME code?, wondering if the old code would work here... or blank... )

8). input immobilizer code & confirm

9.) then it programs the unit

[tholyoak]

With a new DME, the old DME code and immob. codes are justi zeros. The 'old' code represents the codes currently in the DME you are trying to program. The new DME and immobilizer codes are what you want it to be, in your case, the codes to match the DME you are replacing. Without the dme programming and immobilzer codes for a used dme to enter as the old codes, you can't reprogram a used (previously coded) DME.

-Todd

[logray]

Makes sense now, thank you!

[Wayne R. Dempsey]

Rule of thumb for anyone buying a used DME on eBay. Get the codes from the donor car, or at a bare minimum, get the VIN number of the donor car and then find a friendly Porsche dealer who can get you the information out of the Porsche dealer system (called IPAS).

The 7.2 DMEs used on the 2000- Boxsters and the 3.4 996s have gotten very expensive lately ($5000+), so I expect a bunch of people to be buying them from eBay in the future. But again, they are worthless without the above information.

-Wayne

Edited May 16, 2010 by Wayne R. Dempsey

[996noob]

With a new DME, the old DME code and immob. codes are justi zeros. The 'old' code represents the codes currently in the DME you are trying to program. The new DME and immobilizer codes are what you want it to be, in your case, the codes to match the DME you are replacing. Without the dme programming and immobilzer codes for a used dme to enter as the old codes, you can't reprogram a used (previously coded) DME.

-Todd

Question: In the case of reprogramming the same DME in the same car (same VIN), for example, changing region or country, or upgrading to x51, are the 'old' codes the same as the 'new' codes, since it is the same DME and same car (VIN)? So, key into the PST2 or PIWIS the same code when prompted for reading and writing phases?

[logray]

Yes old codes are the same as new codes during a reflash.

[996noob]

I recently attempted this and I am glad to report that the info is spot on. Thanks!

[logray]

Nice work

[rattlsnak]

Bringing this out of the dead files.. Purchased a salvaged donor '00 996 car for the drive train and want to get it running before we pull it out and do the swap. We had no key, so we sent the immobilzer and DME to george at specialized and he sent us back a valet key head coded to the the immobilzer so everything should be good i would think. Anyway, when we try to start it, the starter wont engage. It is not getting the signal to close the start relay from the DME so i assume it is stuck in some kind of anti theft mode? Any direction on what to check next?

[Ahsai]

Clutch switch working and clutch depressed?

[rattlsnak]

yep, checked with a meter to confirm.. anything else?

[Ahsai]

So there's 12v power to the start lock relay (pin 86) when key is in crank position but DME is NOT supplying the GROUND to energize the relay (pin 85)? Is fuse C1 (engine electronics) good?

Edited February 15, 2014 by Ahsai

[rattlsnak]

Correct and yes.. except according to the manual the pin numbers are slightly different.

Edited February 15, 2014 by rattlsnak

[Ahsai]

That does sound like an immobilizer problem. Does your key head have the immobolizer pill (don't know what it's called) installed? If you have Durametric, I rememeber it shows you if the immobilizer is activated although I have never looked into that in detail.

[Ahsai]

What if you jump the start lock relay pins 30 and 87 so power can be supplied to the starter? Then when you crank, if starter spins and engine fires up, you can eliminate the immobilizer and focus on broken wire between the DME and the relay. If the starter spins but engine does not fire up, most like it's the immobilizer. You can also check for sparks during cranking. The immo will also disable spark and fuel.