Edit: this thread started as a "no start" thread with no fuel pump oressure and no power to the fuel pump. I suspected early on that the PCM was bad, and orderred one used from a junkyard on a saturday morning. I spent the next few days waiting on the new pcm to come in, and continued to try and diagnose an alternate electrical issue. Every test I performed continued to point to PCM failure and I documented each below. If you suspect PCM failure, there are some good tips and tests that can be performed to help you pull the trigger on a replacement. To my knowlege the only way to test one directly is to try it in another truck, and that's not always an option.

I did the hutch mod last weekend and the filter I used was too small. Had some issues with very low fuel pressure and fuel starvation. Put on a big filter/separator Tuesday and have had great fuel pressure since.

Wednesday morning at a red light the truck just shut off. Turned key off and back on and it started right back up. I figured id buy a spare CPS for the glovebox as my first guess incase it happened again.

Well today it happened again in the bank parking lot, only this time there was zero fuel pressure and no restart. Opened the door to listen for the pump and nothing. Checked it with a test light and meter while someone else turned the key on. No power at the pump. I pulled the jumper cables out and ran power from the battery to the pump and it comes on with strong pressure.

Checked all fuses, and looked at the book to determine fuel pump fuse. Pulled it out and checked it, and swapped it with another just incase. No change. Unplugged the fuel bowl heater and checked #30, but I think the 02-03 are different. My #30 was for headlights I think. Anyway, can't locate any fuses that are bad.

My WTS light (actually the squiggly line) comes on and goes off as it should. CEL stays on. Pulled all the sensors with Vref signal and no change, which I didn't expect anyway... Pulled the chip, no change. Checked the inertia shutoff switch, no change. Got it home and borrowed my neighbors diablo to pull codes. Can't find PCM. I do have power at the obd2 port and cig lighter.

So, looks like the PCM is gone. Before I order one, I'd like to rule out the fuel pump relay which is in the central junction box for 02-03. I think I will hard wire the pump up and try to start it while I have good pressure.

Am I missing anything?

 

A spirit dance for the Powerstroke Gods?

Think you got it all covered Brother.

 

Don't forget to check the inertia fuel shutoff switch.

 

Somethings killed the PCM circuit as you believe, but it doesn't necessarily mean the PCM is dead. Was the chip loose or anything? That can kill a PCM, but otherwise, they don't just die that often.

A short to ground or something will sometimes cause the PCM not to power up, so I'd start with that. When you pulled the chip, you did have the key out of the ignition, correct? With the chip still removed, leave the key in the run position and start pulling and replacing fuses and relays and see if you hear the fuel pump and stuff energize when something is re-installed. I would start with the PCM relay and pull and replace it a dozen times first to see if that will wake up the computer. If that doesn't work, it's time to start grabbing harnesses under the dash and under the hood and give them the wiggle test.

Of course the easy test would be to just swap your PCM into another 7.3 and see if it fires up.

 

I did check the shutoff switch.

Chip didn't appear to be loose when I went to pull it. As far as the key being out, I know better, hell I know a lot better, but it was still in...and on realized it after i pulled it and went to turn the key on and it was already there. yeah it's that kinda day... Does that fry it for sure? If so then there's no point in doing anything else until it's replaced.

 

Seems like I remember later model trucks being fuse 19 or 116, but I'm sure you looked at them all.

With regard to the Key On, that's not good...not sure if it's a definitive though.

 

Its more than likely done...
Today has just been a bad day for everyone....

Still keeping my fingers crossed that its salvageable...

 

19 sounds familiar... I did check them all.

 

You know I was so set on it being something simple and was focused on that feeling of what is feel like when I fixed it. I was just yanking stuff and trying it like a bull in a china shop.

So anyway, I can't find a PCM on fordparts. Guess I'll call in the morning. I'll have to bring it in to have it programmed wont I, unless I order a used one with the same code?

 

thats a bummer jeff, if one of the brothers cant help you out, dont forget about car-part.com thats where i got mine extra one.

 

Internal to the fuse box is a built in relay that you cannot get without taking it apart. Its soldered in and supposedly non serviceable. Perhaps the fuel psi thing made it overheat? Nevermind, reading comprehension was bad. May check harness really well for burnt like the other truck on the forum acting out similarly.

 

Yeah, just looked. There's a couple in Medly,fl, wherever that is. One in Fayetteville, GA which is a little closer. Guess I'll call around tomorrow and see what I can get my hands on.

 

First thing tomorrow I am planning on hardwiring up the pump to the battery. If it cranks then, that points to the relay pretty hard. If not, that points harder to the PCM...

 

JRJAX has pictures of when he took his 02 cjb apart. He eventually found the harness melted that feeds the engine side of the 42 pin connector.

 

No it doesn't fry it for sure, but it greatly increases the odds you screwed the pooch.

On the bright side, there have been more reports than we can count of trucks that stalled due to a loose chip and were fixed by just taping the chip in place. That means there's still a chance the PCM will work.