no signal from icm to ecm? Help

[bulldoser50]

well i took my explorer to a shop and they determined i have no injector pulse and they traced the problem to the icm not giving a signal to the ecm? but i am getting spark??? i picked a icm up at a junkyard and did nothing is there anything i can do to make sure this one works? as the explorer still dosent run. replaced crank position sensor, egr sensor, egr, maf, and fuel filter, fuel pump turns on.
need help fast
thanks
ryan

 

[MrShorty]

How did they determine that the ICM and PCM weren't communicating? I assume they pulled codes, what codes are in the computer (see my notes on pulling EEC-IV codes in the EEC-IV forum)?

 

[bulldoser50]

they didnt pull any codes i believe, all i pulled when i did it myself was 116 and 11, if anyone wants to try and walk me through checking other items my aim is linebackerstud52
thanks
Ryan

 

[bulldoser50]

anyone????

 

[MrShorty]

They decided the computer and ICM weren't talking to each other without pulling codes? I wonder what they did do.
Your KOEO test results appear incomplete. Your '94 shouldn't stop at two digit codes for anything (that 11 needs another digit, even if it's another 1).
Is that 116 a KOEO code or a CM code, or both? A KOEO 116 is most commonly a result of running the KOEO test on a cold engine.
Did you try the KOER test or does the engine not start?

 

[bulldoser50]

my engine will not start, i just did the key in the on position test, i'll try it again, they did a no-start diagnostic
engine systems inspection ok
charge/start systems testing ok
ignition system testing ok
fuel system testing fail- no injector pulse
mechanical system testing pass

traced problem to icm no signal to ecm, reccomend replace icm

i replaced icm still nothing, there closed for weekend. i tried spraying starter fluid kinda worked for 1/2 sec then nothing, i pressed the fuel pressure valve and when my friend turns the key to the on position i get fuel spraying out but when he turns it over i get nothing? is that normal?
thanks
ryan

 

[MrShorty]

It can be hard to diagnose something like this over the internet. All I can really do is help educate you and hopefully you can figure it out.

Normally when there is something blocking the communication between the ICM and the PCM, I would expect to see some trouble codes in the computer (2xx codes pertain to signals the computer receives from the ICM).

I don't know what diagnostic tests your people performed, so I can't really comment on what they did. Obviously the problem isn't in the ICM itself, (or in any of the other parts you've replaced).

If you get a wiring diagram, you might be able to rewire the thing to see if that fixes it. I expect it would be easier to get a wiring diagram and check the continuity of the wires with an ohmmeter. I don't have a manual right in front of me (but the local library does, so that's where I go when I need the manual).

The computer will run the fuel pump for a few seconds right when the key is turned on, then wait for the PIP/TACH signal to indicate that the engine is rotating. When that signal isn't received, the pump stays off. Your experience with the fuel spray from the fuel rail would be consistent with this scenario. But I'm afraid it does little to help diagnose the issue. What happens if you ground the fuel pump test lead in the self-test connector? Does the fuel pump run all the time? Will the engine start?

I'm afraid I don't have much good advice here. I'm not sure what conditions would cause the ICM and PCM not to communicate but not leave clues in the computer. At this point, the best thing to do might be to talk to your technician tomorrow and see if you can get more information or get him to look at it in more detail. He might be able to shed more light on this than anyone.

Let me think on this some more, too.