ECU Problem - M52 Swapped E30

[Leonstt]

Hello guys,

I have an M52B28 swapped E30 sedan, bone stock M52 with stock ECU which was completed about a year and a half ago.
I have been driving it quite frequently after the rebuild and I haven't had any problems until yesterday. I was driving for about an hour and suddenly I smell something was burning in the cabin. I switched off the car immediately and luckily no fire but the car couldnt start. It cranked, but didnt start.

After a thorough investigation, I found that part of ECU was fried (pic attached). I did check other wires, fuses, and relays and found no indication of a short circuit. This is the only part that was burnt.

Can anyone tell me what part is this and what are the causes of this failure? I'm at lost right now and this makes me worry driving the car

PIC:

https://www.bimmerforums.com/forum/attachment.php?attachmentid=699324&d=1640695984

[e30austin]

i would look at anything that would supply 12v to the controller. battery terminals in the trunk, battery junction box on the firewall, anything in the engine harness that could be a point of chafing, etc.

[TobyB]

Oh, balls- that's the EWS module, isn't it?
Do you know what the donor car was for your swap?

I can't tell you what would make it fail like that-
but it does have a high- current supply to supply the starter motor.
Like Austin, I'd be looking for something that shorted an output from the EWS.
And yes, a dead EWS will cause a no- start. Why it's still in there...

www.bmwteka.com and look at drawings for the E39, since they'll be
representative of the setup for an M52xxB28.

all I gots,
t

[Northern]

I'd try to find the pinout for that connector and try to look for continuity to GND or 12V anywhere it shouldn't be.