I have a ecm no longer available. Has straight short to ground. How can I find the PCB layout or the functional scamatic of the board

 

Is this an Automotive ECM?
Or for what equipment?

 

What is the year and model your ecu is from? Shorts on 12V rail are usually easy to repair.

 

What is the year and model your ecu is from? Shorts on 12V rail are usually easy to repair.

It's for a 1992 ch mack truck. pops the main power fuse as soon as it installed

 

Is this an Automotive ECM?
Or for what equipment?

1992 Mach ch613 mack engine. Pops main power feed fuse as soon as its installed

 

If you open it you will likely find a few large capacitors that have gone bad and leaked out detreating the top layer of pcb.
Probably not an easy repair for a beginner. If your in the states and want to send it out for service let me know. I will send you my company info.

 

If you open it you will likely find a few large capacitors that have gone bad and leaked out detreating the top layer of pcb.
Probably not an easy repair for a beginner. If your in the states and want to send it out for service let me know. I will send you my company info.
Why do people pass judgment on someone you know not if im a beginner or a well qualified tech. Just cause I ask for a diagram. I open many of ecm in my time this has 7 main power feeds and 4 key feeds with 3 auxiliary power feeds. I gave it a quick look over I see no bad burnt spot or blown capacitors. I was under the assumption this form was about learning and helping people with each other's knowledge. But I see it's more about judgments and pushing your bessness narrative.

 

I would have gladly offered as much help as you asked for if given proper information. I even run a YouTube channel where I freely post video's of my repairs so your barking up the wrong tree thinking I'm just "pushing" my business. You had provided nothing however so I could not offer anything except a starting point or a external solution. I don't care if you are a beginner or an electrical engineer. I would have given you the same reply based off the information in front of me.

If you only want your original questioned answered:
"How can I find the PCB layout or the functional scamatic of the board"

You cant. There are no schematics that will be released for the internal circuits of your ecu. You will have to pull out a meter and make it yourself. There are VERY FEW schematics that get out for these type of modules. I do this for a living and have maybe 3 not made by me. Its not really needed though. A short on the main feed is not hard to locate if you know basic electronics. Especially in something that old. The only problems with that one will be getting replacement components if its damaged beyond basic passives and diodes.

 

I'll go out on a limb and guess at a protection diode or transient absorber that's failed short-circuit.

 

Are you sure it is the ECM that is popping the fuse? The only reason I ask is I would assume a 92 Mack would have at least a million miles by now and I know from experience wiring starts to fail around 400,000 miles... even less if people leave harnesses dangling to swing all over and bump into everything else. Does the fuse still blow with the ECM disconnected? My apologies if I ask something you already thought of, but I've been down some mind numbing electrical issues in the past.