I'm interested in reprogramming a Magneti Marelli Microplex MED604C ECU for the ignition of an uno turbo, but I can't seem to find any documentation on this? I'm new to ECU remapping, and my understanding is that all the resources available relate to post 1996 ECUs using the ISO 9141-2 OBD-2 protocol.

Can anyone give me some help on how to approach this, maybe some documentation or what protocols I need to use to access and reprogram this ECU?

  • 1
    If I'm not mistaken, that ECU can't be reprogrammed. It would have to be "chipped", i.e. physically have different chips soldered on. Aug 3, 2015 at 7:14
  • @JuannStrauss Lovely. Still I wouldn't see this as much of an obstacle. Not being able to find any data on the ecu anywhere is the real pain. Was this method common for many older ecu's? Can the chip be reprogrammed outside the ecu (I came across a few newer ecu's where this was the case) or do I have to configure a fresh chip? I guess I could figure out the chip model and try hunt for a data sheet for it for starters and maybe get some more info on its assosiated protocols.
    – javawocky
    Aug 3, 2015 at 8:44
  • It was how things were done in the old days. You'll get a blank EPROM chip, then do whatever it is that needs to be done, then remove the old chip and solder in the new one. Most guys I know who had an Uno Turbo or Opel Superboss went and got aftermarket ECU's like Diktator or Spitronix that could be reflashed via serial or USB cable. Aug 3, 2015 at 8:49
  • I'd actually like to do the old way first just to have that bit of extra understanding, but there is no talk of these ecu's anywhere online. You've given me the best lead so far. Don't suppose you happened to be around during those early days and still have any manuals or know good resources I could research for more clues? I'll take a look at those aftermarket ecu's anyway but that'll be plan B :)
    – javawocky
    Aug 3, 2015 at 9:01
  • I only know about flash tuning the Bosch Motronics and Subaru units. Sorry man. Aug 3, 2015 at 9:30

1 Answer 1


As I noted in the comments, I don't think the ECU is programmable, hence why you can't find anything on the topic online. It can still be "chipped", i.e. removing one or more EPROM's and soldering in a flashed substitute.

Alternatives you could try are either;

a) swapping out the entire ECU with an aftermarket unit, e.g. Diktator, Spitronics, etc or

b) installing a piggyback chip like the UniQ that will intercept signals and change them to fool the ECU.

I don't know if you could get your hands on reasonably priced (or free) software to do the work. You might, but I don't know.

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