What the heck is going on....... .05 ref volts ICP

[Cgrigson1]

04 6.0'recently had no start warm one day it just shut off.
New crank position sensor and still wouldn't start
Towed to garage guy said it starts but I need hpop
Brought it home, I bought scangauge. I replaced IPR and then ICP.
It will start but runs very terribly and zero power will barely go 15 miles an hour and the transmission will barely shift.
ICP ref voltage is .01 KOEO. I have continuity from there it goes into to the CPU to the sensor. .05 v at the pin on the CPU.
Do I have a bad CPU? Most mechanics I have talked said they never have replaced one. Is there another test I can do?
Thanks in advance for your help.

 

[what a mess]

have you changed your fuel filters

 

[Cgrigson1]

No but that's not it. It ran with plenty of power on the way back from the shop and then I got a scan gauge and saw my IPR value jump at least once to 85 and I thought I better change it out plus in had #8 injector plug push through which means I had the high pressure oil rail off and stand pipe and dummy plug gaskets looked good as did the injector. The motor was completely rebuilt 2 1/2 years ago. It started acting really goofy after I did the IPR and injector connector which I did at the same time. Man I can do this stuff it's the electrical issue that's screwing me up plus what could I have possibly done during the IPR deal to screw it up? I can afford to take it to a shop but I'm just trying all I can try to keep from it.
Thanks!

 

[6.0 Tech]

Early or late build? Have you tried running with icp unplugged? May need a pigtail for icp sensor. Also, try unplugging all the other 3 wire sensors. Map, baro, ebp, app, and one other one i cant think of right now. One may be internally shorted causing loss of vref, as they are all spliced off the same output.

 

[Cgrigson1]

It's not an early 04, ICP Is up front passenger. I have gone down the harness and disconnected a lot of those things and didn't notice a change. My biggest deal is I've learned from diesel tech Ron RIP that proper refv to ICP is .24 and I measured .05 at the pin coming out of the CPU. I've seen em on eBay for $100 but just still not sure it's my issue

 

[6.0 Tech]

Yes proper icp koeo is .23-'24. Is the pigtail ok? They can still have issues even on later ones. If it needs a pigtail, only put a ford one on, same with an icp sensor. What kinda throwin me is that you have pretty much 0 vref out of the pcm. Are you measuring this right at the pcm, or in the icp pigtail?

 

[Cgrigson1]

Thanks so much for the reply. I am measuring the refv right at the pin on the CPU. The pigtail looks perfect to me. I have seen a CPU on eBay for $100 but like I mentioned I just hear they never go bad. If voltage is low at the CPU all wiring harnesses and plugs and pigs are eleminated. So it sounds like to me that's an issue Right?
Clay

 

[6.0 Tech]

Not necessarily, unless you have all the connectors unplugged at the pcm, except for what is vital ie power and ground. You could still have another sensor pulling down your voltage. The baro and app are off the body harness of the pcm, as is the map i believe. Ebp and icp are off the engine side.

Had a similar one that had a leaking master/hydroboost that shorted vref to ground in the connectors on the drivers inner fender. Didnt see it until i was chasing wires and the insulation fell off in my hand. It was all swollen from the brake fluid. Wires were shorted together on the bottom side to where you couldnt see it from the top of the engine.

 

[Cgrigson1]

My plan
1) make sure all the 3 wire connectors on that harness are unplugged and then ck refv at ICP
2) disconnect other plugs at CPU except for power and ground and I don't know where that is though. Maybe it's not one of the three? Goal is to see maybe there's another issue such as like you had posssibly?
3) may need to go ahead and remove the harness for full inspection??? Really don't want to have to do this because I fear breaking a connector and not being able to get it back on properly so if I did so would be very careful to take many photos and label what goes where
4) ask for more advice I suppose. I simply can't afford to drop it off somewhere and just hand the mechanic who I have never met and have no clue about his honesty on time charged so I'm gonna give it one more good solid run of effort before I am forced to do so
Thanks again and I super appreciate and need your help!

 

[Cgrigson1]

So went down and unplugged every sensor on that harness I could find, several had wires that were stripped at the clip and even one had both wires stripped and touching, taped em up and no difference at ICP noted. May need a new wiring harness anyway

 

[Cgrigson1]

RefV

No luck so far. Looking more and more like I don't have a choice but to buy a new wiring harness. The first pic was of an injector pigtail. I tried taping it up but not sure if that's gonna work but when running I wasn't getting a code for it so maybe. I taped up what wss exposed on all of these. I have alldata but it isn't very easy to navigate through. I'm basically at a stand still and not too happy about it!! I had hoped to figure something out this weekend

 

[6.0 Tech]

Yeah thats pretty bad. None of those sensors will cause your vref to drop, but you may have an issue elsewhere causing it seeing just those parts of the harness. The injector is on a different harness, but im surprised you werent having issues with the pigtail being lime that. What does the harness look like under the master/hydroboost area?

 

[Cgrigson1]

I inspected it the best I could all the way down and didn't see any chafing. New $650 but ebay $200. I guess I'll make sure and talk to the person selling it and make sure it's 100% good the issue I've seen or they just show a pic of it and who the heck could make out if it's the right one or not. I'll see if they know when we talk before purchase I suppose. Would the ford IDT or IDP or whatever that software is necessarily be able to diagnose my issue better than my scan gauge? I'm at a point where I just gotta either ship it to a shop and hope for the best or really talk to an absolute expert that can help me and I'll pay

 

[6.0 Tech]

The computer may not help anymore with showing the issue, especially if you are getting these readings manually with a volt meter.

Since we are this far in, what color wire are you checking? Which pin at the pcm and icp sensor? Just to make sure you are on the correct pin.

 

[Cgrigson1]

I had another guy on another forum send me the diagram so was on he right wire. Bottom on the pod tail and bottom left corner at the CPU

 

[6.0 Tech]

Ok, that did not sound right. I loomed it up vref is on the top left pin on the icp when looking at it. It is thr bn/wh wire. The pin you were on was the icp monitor pin, which just tells the computer how much ic there is. At the pcm, you shpuld be in the middle connector and pin 29, which is on the second row from the botto. With the hinge up, and the fifth small pin from the right when looking at the face of the connector.

Try these wires, and lets see where youre at.

 

[Cgrigson1]

Ok. I went out to ck it and batteries were
Down to 6 volts??? I'm charging and will ck tomorrow.
Thanks!!

 

[Cgrigson1]

Ok. So I reall quickly went out and ckecked the top left on the ICP connector and got 5 volts. Not .5 but a true 5. I'll proceed to ck it at the pin. Not sure I got the connector back on the EOT sensor correctly. It's a two wire two pin sensor and don't remember if the part that sticks out on the connector went forward or backwards. I'll double ck that as well while I'm monkeying around on it.
Thanks

 

[6.0 Tech]

Welcome man. Hopefully she runs good now. On the eot sensor, the flat oval shaped pin on the sensor goes away from where the locking tab is. The locking tab will go toward the angled pin on the sensor.

 

[Cgrigson1]

I just went out and started it. Was really slow to build ICP but did Start. I was getting 120O psi at idle and IPR was at 38%. iCV was showing .10 at idle however. Just didn't sound right and I didn't attempt to drive it wanted to let it heat up and recheck values. After it ran for a few minutes I noticed a change in sound and it started to struggle a bit and at that time ICP had dropped down into the 700's. I have a leak test fitting and did Test it through the ICP sensor but that only does passenger side correct? Should I take valve cover off driver side and leak test it there as well through dummy plug And will this ck the remainder of the system or will I need to pull the turbo to test apply air straight into the HPoP case on top?
Thanks
Clay.