Ways to determine correct Motronic unit?

[GV12]

Hi guys,

I've been in the process of getting my 535i running again. The Car died suddenly while I was driving it. I have gone through the forum and done all the basics like Fuel Relay, Main Relay, checked fuel pumps etc etc.

I've gotten down to the Motronic unit and the reference sensors. The sensors checked out fine, but have since broken apart like what happens to so many others...So replacement for those are on there way soon.

Anyway, the previous owner did a hack job to the wiring harness that goes to the Motronic. Which leads me to my question... Is there any way to determine the original Motronic unit that came with the car? Like looking up VINs and determining what should be in the car based on what it has?

I ask because in my research my unit is Bosch 0 261 200 061, and apparently that came with the euro M30 high compression motor? I am pretty certain I do not have this, so I don't know if it was swapped out when the original owner had the car, or what.

I just want to make sure I am running the correct unit in the first place, and then hopefully I can get a hold of a correct replacement, as I think it is the source of my problems.

[Bimmerguy2002]

according to Mike W, all american 535's came with the 059 purple sticker, thats all ive seen too

[turbodan]

That ecu should work in any case. You will have no trouble finding an -059 for testing if you want to do so.

How about opening this one up and checking solder joints? Does the coil get 12v with the key in the run position?

[stuartinmn]

-059 is for US spec or euro green spec engines, -061 for euro 'dirty' engines. I swapped in an -059 ecu while troubleshooting my M535i and it ran fine, so I assume you can do the opposite. It may not run right but it should run; the -061 doesn't have provisions for the O2 sensor.

[Brad D.]

I thought you were Nebraska_e28 when I saw your avatar.

[GV12]

Thanks for the helpful info fella's. I'll try to track down a 059 box at the pull-a-part tomorrow, and look on ebay and here too.

I thought you were Nebraska_e28 when I saw your avatar.

Haha, sorry for the confusion. I just threw that avatar up there today. Been sitting on my harddrive for forever! I like to change mine around a lot, so it'll soon be something else.

[Brad D.]

You shouldn't have too much trouble tracking one down.

[wkohler]

You shouldn't have too much trouble tracking one down.

What? An avatar?

[GV12]

That ecu should work in any case. You will have no trouble finding an -059 for testing if you want to do so.

How about opening this one up and checking solder joints? Does the coil get 12v with the key in the run position?

Forgot to reply to this, sorry!

I have my ecu apart again as we speak. I took it apart earlier, and I found 3 solder joints that looked suspect, so I reflowed them, but that didn't cure my problem. I'm just having another look now to see if I may have missed others.

I thought I'd get a hold of another ecu to test, and if it's not the problem, then I'll have a spare when I end up really needing it.

Oh, and I'm pretty sure I'm getting volts at the coil. I have tried so many things, hard to remember it all I'll be sure to try again tomorrow.