So, I bought My Wife a 2007 R56 Mini Cooper That Had The Famous Carbon Buildup problem.

I Had The Cylinder Head Completely Re-built. Installed Everything Back On the Vehicle And What do you know.... Melted Coil #2 Not Once But TWICE!

So, I decided To Dig a little deeper and started tracing back the wiring for ignition coil #2

I began with the ECM Plugged In and Tested the (Yellow Wire) which was not outputting any voltage and found it is grounded out. So, I removed the wire harness from the ECM And Checked from end to end to see if the yellow wire was in fact grounded somewhere in the harnes. I Came to the conclusion IT WAS NOT.

So, Me being somewhat of a component lever repair man with computers. (I Decided To Dig a Little Deeper by removing the ECM And Tracing back where the pin leads to for cylinder #2 on the motherboard of the ECM.

I found all 4 ignition wires for each cylinder run to a set of MOSFETS Part # N171AD. I Traced cylinder #2's Mosfet, Removed it from the motherboard and what do you know No Melted Coil Pack when the Igntion is ON. it stays completely cold as it should.

Now for the fun part.... finding the component to replace it with....

I am not much of a FORUM Poster but I figured this is something that would help alot of people. And maybe I can repair it for them if needed

I will let you know my findings when i Get the New IC for the ECM and install It.

 

I look forward to the outcome, you sir have some skills that I wish had!

 

I have been in High End computer Business for five years now. I also used to own a performance shop so, When it comes to Cars and Electronics I Am fairly Skilled.

I just ordered a Parts ECM. and Will be removing the much needed MOSFET from it and installing it on the original.

I should have it ready by early this week.

Will keep posted.

 

Update*

Just got a parts ECU In. Replaced the bad MOSFET With a good one from the parts ECU. The MOSFET was a Different Part # than the one on the original ECU But, I Decided To Give it a try anyway.

MOSFET PART # n634ab is what I Used to replace the original.

Popped the ECU in the card and what do you know. Fire on all 4 Cylinders. No melted coil Pack # 2

I believe this was a success.

Hope this helps anyone in the future.

If you need soldering or assistance please feel free to contact me via PM

 

Do you want to fix mine.. lol

 

Just wanted to drop a line and say thank you for this info. I had the same problem on 13 mini. Went through 2 coils. I bought another ecu at a junk yard and that didn’t work so I opened both up and replaced cylinder 3. Worked like a charm, no over heating of the coil and it is firing like it is supposed to.

Thank you again for posting. It really helped in the diagnostics and repair. Saved me about 400 dollars in getting the salvaged one reprogrammed.

 

[img alt="Ecm how does the cover come off it’s not easy
"]https://cimg1.ibsrv.net/gimg/www.northamericanmotoring.com-vbulletin/2000x1504/image_c94ead1f0a402c2f514edaf657d708ac8c02ddcd.jpg[/img]
Ecm how does the cover come off it’s not easy
How did you get this back cover off? I was having a hard time once the screws are out. It doesn’t seem to wanna come off.