My 2 cents.

I would agree that PCM failure is relatively rare. I have had only one fail and that was on a 98 F150 with the EECV PCM. I was an electronics tech with way too much experience and I have seen my share of leaky electrolytic capacitors, but honestly, I have never found leaky electrolytics in a Ford PCM. Possibly something to do with our climate, but I have no doubt the capacitor failures are real and they can cause quite a variety of problems.

 

I have several PCM modules with leaky electrolytics and seen quit a few on this forum.
But all of the them were out of a 1995 or older Ford trucks.
I have not heard or seen any leaky electrolytics in the 1996 or newer trucks.

 

If you've had a bad one or more, its common, if you've never had a bad one its uncommon.
Luck of the draw with 25+ year old electronics in a semi outside environment.

 

Here's what the insides of my old one looks like.

 

Yup, that thing is toast. Not even worth trying to save.

 

Someone let the smoke out. Electronics runs on smoke. That's not good!

 

Yikes, that's not a capacitor leak!

 

Looks like someone washed the engine bay.
Happens a lot.

 

Could rain have done this?

Or maybe going through a car wash?

 

When the grease drys out in the PCM connector connector after 20 years and water gets in the connector the PCM will let out smoke.
This has happen to a few posters on this site after washing the engine bay with a high pressure washer.
As far as rain or going through a car wash I have not heard of that causing it but driving through high water might.

 

So the original PCM is toast, yet in the first post the OP says that two more PCMs were tried. Some possibilities:
- Whatever caused the original PCM to fry went on to fry those subsequent two PCMs as well.
- When the original PCM went out it took out something downstream too (including wiring), and that's now why new PCMs don't fix the problem

 

So far, still no solution after several PCM's.

The present status is the engine will run with the SPOUT connector pulled out and the fuel pump relay manually grounded.

There is no ignition with it plugged in.

And no fuel pump activation in either state of the SPOUT connector.

This has been the case on at least 2 of the PCM's we have tried.

Any thoughts out there among the Illuminati?

-Jack (missing my truck in central Texas)

 

You are going to have to unplug everything, and go through the harness wire by wire.
Something must be shorted badly.
I had a rat chew my EFI harness at the back of engine, didn't know until I pulled it out.

Swapping computers is not your problem, burned out computer is the effect that something else is causing.

 

I could not agree more, Mr. White. Thanks.

The guy who is working this problem for me has already dragged out the harness and is looking for damage.

Sadly so far, everything has checked out, but the battle rages on...

 

Sounds like no power to the PCM.
Check for power at pins 55, 71 an 97 of the PCM.
If no power at pin 71 & 97 check that power is leaving the PCM Power relay pin 87 with the key in the run position.
The wire #361 may be open between the PCM Power relay and the connector of the PCM.