You can take the ECU connector off and do a continuity check between the self test connector pins and the corresponding ECU connector pins. If all that checks out, then the computer is definitely broken if it won't go into self test mode.

Could you take some pictures of the inside of your computer, specifically around the capacitors (metal cans sticking up off the board)

 

I took pictures of it but can't figure out how to put them on here. I'm guessing the multimeter has to be in ohms? Just stick the positive on the harness connector and the negative on the computer connection? Im still not the greatest with electrical stuff yet. Good with directions though.

 

Ohms would work, but many digital multi meters have a continuity mode where it makes a beep sound if you touch the two probes together. That makes diagnostics faster and easier.

If you have the pictures on your computer or phone, it's easy to get them on here. When you make a post, look in the settings bar (where the font size/color, etc.. is) above the text box. You'll see a little yellow square with black "mountains" in it. Click that, and it will allow you to upload a picture.

 

Here are some pictures thanks for that. I plugged it back up but if you need more pictures I can take some more when I get back home.

 

I see two that look OK but is their a thread one hiding behind the power transistor that I can not see in the photos. That is the location that has the bad one most of the time.

 

Actually I was going to say the capacitor by the connector seems to be bulging.

Keep in mind that just because the capacitors aren't leaking, doesn't mean they're good either.

 

I agree with Lead Head.

It looks like the capacitor is bulging. Maybe not leaking, but does show a problem.

 

What does that one do? Does that explain why it works fine sometimes then just dies when it feels like it?
I gotta go to work in a few. I was out a bit longer than I expected. I'm off tomorrow so I can screw around with it more. Do y'all want more pictures?

 

Ok I just looked up failed capacitors I was expecting some kind of goo leaking out of them but it's either a yellow or orange liquid right? I noticed some orange stains on the board when I had it out but I didn't think anything about it. I don't know I guess I'll have to pull it back out. If I end up replacing it are them megasquirt systems any good?

 

Megasquirt system? For what? Just go to the junkyard and roll the dice on a used PCM or get a reman from the parts house.

 

Yeah I guess you're right. I ain't trying for no race truck or nothing like that. Maybe a couple runs at the beanfield race every couple months but mainly just a dependable truck that ain't gonna leave me beside the road.

 

For the price of getting a Megasquirt system sorted you could put like 5 re-manufactured PCMs in your truck.

 

2X on a junkyard PCM or a reman unit.

As you are learning electrical repair on your truck, Megasquirt is MUCH more advance in electronics/programming than the factory PCM system. I shied away from it as I did not want to mess up a engine with a programming error.

 

Scratch that then. As for dependability which would y'all choose a remanufactured or a salvage?

 

Reman. Salvage yard can be hit/miss.