96 B5 with no ECU

[speec]

I recently bought a 1996 B5 Quattro with an 2.8 12v AAH/AFC engine, the car is in a very good condition and is my second B5 (love this car), except for a little detail, it has no ECU.

Now, as far as I know there are different ECU's for the 96 AFC Quattro's, the 8D0 906 266A (MMS-411) with the yellow sticker, and the 8D0 906 266B (MMS-411A/MMS-411B/MMS-411C) with the red sticker, they are both Hitachi.

I have no clue what ECU fits this car, is there any way to find it? I will really appreciate any help!!

Thanks!

[Bordom]

Figure out which is manual. I'm fairly sure the usual ECU's are 411A

[speec]

Oh, I forgot to mention that is manual transmision!

[speec]

Nobody else? I'm going to buy the 8D0 906 266B MMS-411A

[Victorymike18]

So this is a really old thread, but I may have some useful info to add if anyone else ever searches:

I have a '97 A4 5-speed quattro. My ECU is a MMS 411B
A friend has a '96 A4 5-speed quattro parts car, and his ECU is a MMS 411A

Interestingly, his '96 has fuel injectors with two-hole pintles, and my '97 has four-hole pintles. According to an AudiWorld thread, the four-hole injectors superseded the two-hole (which makes sense) and can be installed as replacements. However, I learned the hard way that it does not work the other way around. I had my friends spare '96 injectors professionally cleaned and installed them in my '97 but ran into continuous misfires and had to go back to my originals...

So it seems to me that at the very least there's a difference in fuel maps between the two ECU's. Being very early OBD2 cars in North America, this isn't surprising as Audi made a lot of small changes between '96 & '97 cars.

[Blazius]

So this is a really old thread, but I may have some useful info to add if anyone else ever searches:

I have a '97 A4 5-speed quattro. My ECU is a MMS 411B
A friend has a '96 A4 5-speed quattro parts car, and his ECU is a MMS 411A

Interestingly, his '96 has fuel injectors with two-hole pintles, and my '97 has four-hole pintles. According to an AudiWorld thread, the four-hole injectors superseded the two-hole (which makes sense) and can be installed as replacements. However, I learned the hard way that it does not work the other way around. I had my friends spare '96 injectors professionally cleaned and installed them in my '97 but ran into continuous misfires and had to go back to my originals...

So it seems to me that at the very least there's a difference in fuel maps between the two ECU's. Being very early OBD2 cars in North America, this isn't surprising as Audi made a lot of small changes between '96 & '97 cars.

The injector change needs to be reflected in the software ofcourse, that is why you cant just swap em over as bolton, but rest is true indeed.