PCM: Regular or extra-crispy?
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From: Jasper, MO
PCM: Regular or extra-crispy?
OK, I had a guy get pulled in to our yard on a hook. He said, he was just going down a sidestreet, when all of a sudden there was a lurch, a big puff of black smoke, and then NOTHING. won't start, won't run, etc....
here is what I have done to this thing thus far:
Replaced batteries
replaced CPS
Replaced Fuel Filter and drained rails til fresh
checked all fuses
checked harnesses; visually OK
HPOP was about 2inches low, topped off and hasn't drained back
Truck was at 1/8 tank...added 5 gal to be sure
checked intake and turbo (just in case)
Oil pressure comes up quick
ALL dash lights work
connections clean
There is a partial "hit' when cranking, like one cylinder trying to work
stood back, yelled and screamed at it til I was hoarse!
Tried my Auto-Xray scanner... it said no codes. Bought and tried Car-code OBD-II from OBD2.com with complete pkg. it is not getting ANY info from the pcm; NO CODES, NO DATA, no unit#s, etc.
Please.... help me save my hair! Can I try another PCM from a boneyard, or do I just dump money into a new one?
what am I missing here...?
is this pcm toast? would it show all the dash lights if it was?
here is what I have done to this thing thus far:
Replaced batteries
replaced CPS
Replaced Fuel Filter and drained rails til fresh
checked all fuses
checked harnesses; visually OK
HPOP was about 2inches low, topped off and hasn't drained back
Truck was at 1/8 tank...added 5 gal to be sure
checked intake and turbo (just in case)
Oil pressure comes up quick
ALL dash lights work
connections clean
There is a partial "hit' when cranking, like one cylinder trying to work
stood back, yelled and screamed at it til I was hoarse!
Tried my Auto-Xray scanner... it said no codes. Bought and tried Car-code OBD-II from OBD2.com with complete pkg. it is not getting ANY info from the pcm; NO CODES, NO DATA, no unit#s, etc.
Please.... help me save my hair! Can I try another PCM from a boneyard, or do I just dump money into a new one?
what am I missing here...?
is this pcm toast? would it show all the dash lights if it was?
Post Fiend
Joined: Feb 2006
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From: Middle Tennessee
Do you get a WTS light and is the pump running when you turn the key? Do both of those cycle like they should?
Also, by oil press comes up quick do you mean it is showing on the gauge during cranking? I thought it would not start.
Also, by oil press comes up quick do you mean it is showing on the gauge during cranking? I thought it would not start.
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From: Jasper, MO
Originally Posted by Tenn01PSD350
Do you get a WTS light and is the pump running when you turn the key? Do both of those cycle like they should?
Also, by oil press comes up quick do you mean it is showing on the gauge during cranking? I thought it would not start.
Also, by oil press comes up quick do you mean it is showing on the gauge during cranking? I thought it would not start.
Thanks for asking, tho!
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From: Jasper, MO
Originally Posted by Casey
Is the PCM getting power? There is a relay that powers the PCM. I've seen the relay die and the PCM shuts down, along with the engine.
WHen I am runnng the test program, I have heard a "click" off in that general diretion, and then the thing stops communicating til I completely start over.
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From: Jasper, MO
we just tried to do a buzz and got nothing. getting it on a charger to keep those new batts up
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Post Fiend
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Well, it may be something to do with the UVC harness. There are two connectors going into the valve cover gasket below each valve cover, and they control the injectors and the glowplugs. If one of those is loose or unplugged, it will cause some major problems. Also see if you can peel back the wire loom, and look to see if any of the wires are chafed. Sometimes just wiggling these connectors will fix it.
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From: Jasper, MO
I will have to look into that tomorrow, as I am out of daylight lol.. but I do appreciate it. I've read about it before, but what concerns me is this PCM having no info at all... is that normal? Guess I could try it on MY truck, eh? but then again, my PCM came from Jody...
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From: Jasper, MO
OK, this truck has nowbeen sitting for almost a MONTH because I was on the road turning some miles. For the thanksgiving Holiday, the other 5 trucks are in, so I took my lil laptop here around to EACH of them and ran the car-code OBDII program. got info off of every one of them EXCEPT the dead horse.
I guess now it IS time to replace the PCM. Just I don't understand why all the OTHER functions work, like the WTS light, etc...yet I can get no info out of it.
I guess now it IS time to replace the PCM. Just I don't understand why all the OTHER functions work, like the WTS light, etc...yet I can get no info out of it.
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From: Jasper, MO
Originally Posted by amiller93
Have you checked all of the fuses under the dash. The ODB port shares a fuse with the Cig lighter?
<TABLE class=tborder cellSpacing=1 cellPadding=4 width="100%" align=center border=0><TBODY><TR title="Post 4155002" vAlign=top><TD class=alt1 align=middle width=125>Tenn01PSD350</TD><TD class=alt2>Any way to swap the pcm out with one of the other trucks? Do you have another one that will work?</TD></TR></TBODY></TABLE>
I can... my only fear is that if this PCM is toast due to a short I'd be crapping out another PCM. Maybe I can buy one from a junkyard, test it in a good truck, THEN try it in the dead horse?
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From: Jasper, MO
sorry, I forgot to mention we replaced that a while back. All the wiring seems ok going INTO the VCs, and one other point I need to make... When I have the scanning software all hooked up and ready, it connects OK, but as soon as I hit "test", I hear a click and the OBDII disconnects or shows that "busy signal" until it fails. I have to cycle the key off and on again and restart the program for it to reconnect, and it just does it again (only on this one truck)