Hi Everybody,

I've been reading a bunch of other posts and watching videos on ECM repairs in preparation for attempting to fix mine. I pulled the ECM expecting to have to replace the capacitors and as expected 2 out of the 3 of them are leaking and corroded. My question is about the two parts that I highlighted with red boxes. In everyone else's pictures and videos, I didn't see a single other ECM that had corrosion in those two areas. I don't know what effect these two damaged areas might have on the truck if anything. If anyone has any input I'd appreciate some guidance.

 

The area to the back of the ECM is the J3 connector. It looks like dielectric grease has been applied to it. Don't clean it off, it's protecting the contacts. The brown staining you see is not leaking capacitors. It may be heat related, but it is not enough to cause any problems. Quite often, that sort of stain is in the conformal coating that the entire circuit board was covered in when it was built. Soldering, or cleaning it off removes the coating and any protection it may provide. The component you have outlined is some sort of inline flat package circuit which would likely be made of unobtanium. Leave it alone! Frankly, those caps do not look bad. Were you having problems? If this is simply "preventive maintenance", put the covers back on and leave it alone.

 

ugh, ecm repair.

First off I done *see* any hard trouble spots there, unlike say the chrysler j body verts where water drips on it...

sure, replace the caps, voltage and value and dont use junk. replace with 105*c units. the SIP in there...gotta reg number off of it? I doubt that is logic but is perhaps a voltage amp, multiple op amps or even D/A something

Is this double sided? they were made parts picked and wave soldered, all the thru hole stuff solders on BOTH side. and dont touch the SMD stuff. from the looks of your pic, there are no traces running UNDER the chips (unlike the motorrola built chrysler junk) so what made you go in there in the first place?

PS - these things just never go bad and the 'rebuilders' really dont, they wash em and change caps and perhaps diodes...if none of those are zeners, generally a 1N4148 will replace the glass ones. the black plastic diodes with silver cathode bands can be handled by pretty much any 1amp 100+PIV diode and I see a biggun in the 3-5 amp range.

I count a couple to220 devices w/no heatsink...any chance they have a 78M05 or 78M08, 78M12 marking on them? if so that is your voltage regs

I see no obvious signs of green leaching (copper) and you have what looks to be 3 families of resistors...the little tan ones are PROBABLY flame proofs. do you have a SCM for it before you fire up the solder iron? what about Charlies book on it - any help?