Dismantling ECUs for fun and profit

[Babalouie]

Like a Christopher Nolan movie, I'm gonna start at the end, and then work back to the beginning.  Hmm...what do we have here, an aftermarket chip, with a rather...er... "colourful" reputation, in case you hadn't heard: LINK

Now, as we ponder the sequence of events that led to this shocking discovery, I'll have to take you back....to three weeks ago.  The 964 has always had an unsteady idle.  So the common forum wisdom, is to perform an idle-adaptation.  It's basically like a hard-reset for the idle function, and can only be done via a diagnostic tester. So I'd asked Autohaus Hamilton to have a go at this, at the recent major service.  But their tester couldn't talk to the DME, and Hamiltons suggested that maybe there's an aftermarket chip in there (which might also explain the poor idling).

 

So, out comes the DME, to see what's in there.  Firstly, it lives under the passenger seat, where it's secured by 4 easily-reached nuts.

 

Undo the nuts, and the DME slides out, and you can unclip the plug.

 

Interestingly...the DME doesn't look like it's been tampered with.

 

And the clips that crimp onto the cover don't look like they've ever been prised apart.

 

But just to be sure...let's have a look.

 

First you notice that the unit is of a double-decker configuration.  And the first step it to separate the pillar-shaped clips on the left side.

[Babalouie]

Then prise these clips in the plug iself...

 

Whereupon the top deck slides back, and opens like a book.

 

...where the main chip is held in with a plastic clip...

 

..where underneath, the chip doesn't look aftermarket, but I google that number on the chip, and find a few links to euro chip tuning joints: http://www.prorace.cl/autossoportados/porsche/todos/porsche911-carrera2.htm and http://www.tecnosport.to/mappe/tabella010.htm

But I suspect that those sites are just referencing the stock Porsche chip number, and I put the DME back together. But that's not all...the DME in the car is part number 964.618.124.03, which is consistent with my car being a later 964 with the plastic inlet manifold.

However...I do have a spare DME, which came with an early, alloy 964 manifold, and that has an older part number of 911.618.124.04. At first I thought that the 911 prefix might mean that this is actually a Carrera 3.2 DME, but it turns out that this is simply the strange numbering that Porsche used for the first year or two of production.

And interestingly...this DOES look like it's been tampered with!

I take it apart...to reveal its dark secret within

So, what do we know now. Ironically I think I don't have an aftermarket chip in the car, but I DO have a chip...buried in my spare DME which I've never used.

 

 

Hmm...anyone wanna buy a DME? :cheers:

[Uncle]

Powerchip do.not.want

LoL

[SteamWolf]

lol powerfail

[Babalouie]

Powerchip do.not.want

LoL

I'll throw it in with the manifold as a freebie

[Greg944]

The question remains:

Why the original DME can not be communicated with?

Cheers

Greg