NO Start
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Okay, maybe someone knows the answer to this. My signal wire (red/yellow) at the IPR connector is always above 0.25 volts, normally around 0.36.
Out of the 42 pin connector it measures 0.36 also.
But I stabbed the wire with a pin today where it comes out of PCM and it is over 12 volts. I think I am goofy.
Out of the 42 pin connector it measures 0.36 also.
But I stabbed the wire with a pin today where it comes out of PCM and it is over 12 volts. I think I am goofy.
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I actually read somewhere that the volts at the coil with KOEO should be 1.3 or so. For a time that is what I was getting. But it wouldn't start. Once I got the volts down to around 0.36 the truck would start. Maybe something else going on.
My codes sure point to the IPR/ICP interaction.
My codes sure point to the IPR/ICP interaction.
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Yes, I attach one lead to the neg battery post and then measure volts with other lead.
For instance at the IPR connector the signal wire is now measuring around 0.36 volts and coming out of the 42 pin it measures the same.
But the voltage coming out of the PCM was measuring over 12 volts when I pricked it with a pin and measured the volts.
This is driving me insane.
For instance at the IPR connector the signal wire is now measuring around 0.36 volts and coming out of the 42 pin it measures the same.
But the voltage coming out of the PCM was measuring over 12 volts when I pricked it with a pin and measured the volts.
This is driving me insane.
Post Fiend
Joined: Dec 2010
Posts: 10,121
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From: Orrville, Ohio
Sounds to me like there must be an issue between the 42 pin connector and the PCM if you're absolutely sure it is the same wire. If you have verified that the color code is the same, I would either open the wiring harness and inspect the wire from PCM to the 42 pin connector, or just install a new wire and test it again. Just as a test you could use some of those insulation cutting splice connectors (solderless splices) to see whether it works. I would only do this: 1 as a very temporary test as those connectors don't seem to hold up very well in an environment like the engine compartment (or any environment for that matter) and 2 after you have double, triple checked that it is the same wire. If you cross that IPR wire with another 12V supply, you run the risk of damaging either the PCM or the IPR. For a long-term solution you're really best off to run a new wire and solder it in place then seal things up with some heat shrink tubing.
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Postmaster
Joined: Sep 2007
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From: Medford Oregon
If you had the PCM connector unplugged when testing then it would be 12 volts (battery). PCM is what pulls the line low. Otherwise it's just a wire so if your sure it's the same wire at both ends (do a resistance check) and you get different readings at each end then .... must be the wire.
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I was pricking the wire with a pin and measuring the voltage with the PCM connector connected.
I measured the voltage today(PCM connector connected) and it was the same(0.36) before and after the 42 pin connector. That is with the IPR connector disconnected.
I am thinking that maybe the other day when I measured it and the voltage was 12 plus, I didn't have the IPR connector disconnected and the 12 volt hot leg was cycling through the IPR itself and going back to the PCM. I will have a new ICP in the truck tomorrow and see if that helps.
I have a question about the PCM. Can you get the chip out without removing the PCM? Is the chip what you see looking straight at the PCM? I wiggled it and it moves around, is that okay?
I measured the voltage today(PCM connector connected) and it was the same(0.36) before and after the 42 pin connector. That is with the IPR connector disconnected.
I am thinking that maybe the other day when I measured it and the voltage was 12 plus, I didn't have the IPR connector disconnected and the 12 volt hot leg was cycling through the IPR itself and going back to the PCM. I will have a new ICP in the truck tomorrow and see if that helps.
I have a question about the PCM. Can you get the chip out without removing the PCM? Is the chip what you see looking straight at the PCM? I wiggled it and it moves around, is that okay?
Postmaster
Joined: Sep 2007
Posts: 4,195
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From: Medford Oregon
Dan, after 19 pages of conversation how did I miss the PCM was chipped ... 
I would not get to caught up on the volt meter thing reading 0.36 ( or whatever it was) instead of lower, it's probably just the meter. Try another one and compare the results.
I would not get to caught up on the volt meter thing reading 0.36 ( or whatever it was) instead of lower, it's probably just the meter. Try another one and compare the results.
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I don't know if the PCM is chipped or not. I don't think it is, I have had it since 96 and I don't think the PO did anything to it. I was just trying to figure out how to get it out of the truck. I thought all PCM's had some kind of a chip in them. Man, I know very little about lots of this stuff.
