79jasper
Chickenhawk
Just to verify, you completely disconnected the glowplug relay?
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Sent from my SM-N960U using Tapatalk
Pcm swap???
- Thread starter 90f250
- Start date
90f250
Full Access Member
as in, taking each wiring off the relay? all 4 of them? yes
79jasper
Chickenhawk
Yep.
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90f250
Full Access Member
Yes I did and it also hasn't done anything either. I keep seeing things randomly about an auxiliary powertrain control module... would it shut down my main pcm? I think I just found the damn thing sitting middle of the dash on the floor behind a black plastic cover. Not sure if it's a problem or not but hell I've tested everything else i can find. Anyone know?
79jasper
Chickenhawk
Haven't heard of that. Heard of a AICM (high idle box).
Anything is possible.
Okay, quick search, appears to be one in the same.
Sent from my SM-N960U using Tapatalk
Anything is possible.
Okay, quick search, appears to be one in the same.
Sent from my SM-N960U using Tapatalk
90f250
Full Access Member
bbjordan
Snow Monkey
I'm leaning toward wiring as the problem too. I would check the PCMs, both of them, in another vehicle to see if they work. If they do...then it's probably the wiring. The APCM can just be unplugged if it is suspect. How is the ground between the engine and the cab? You could put in an addition ground wire just for testing.
This is a tough problem. Should be a journeyman exam.
This is a tough problem. Should be a journeyman exam.
greenskeeper
Full Access Member
Can any of those scanners connect to another truck of similar vintage? I’ve only used autoenginuity and know that it connects to PSDs
SES light means the PCM has power and a stored code, you just need to figure how to connect to it.
Do you have power to the cigarette lighter? I believe it’s on the same fuse as the OBD port, if there’s no power to the port then the scan tool won’t connect to the PCM.
90f250
Full Access Member
I'm leaning toward wiring as the problem too. I would check the PCMs, both of them, in another vehicle to see if they work. If they do...then it's probably the wiring. The APCM can just be unplugged if it is suspect. How is the ground between the engine and the cab? You could put in an addition ground wire just for testing.
This is a tough problem. Should be a journeyman exam.
Yes I took every single ground off and wire wheeled them all to make sure it's got good ground everywhere, lol. I hate wiring gremlins...the only issue is I dont have another psd around that uses the dpc-402 pcm like mine does. And I just had mine rebuilt because of all this mess thinking that just maybe it was the cause, but apparently not
90f250
Full Access Member
Yes they will all 3 connect to pretty much anything with an obd 2 port. I do have power at cig lighter and at the obd port. But no scan tool will actually link to the pcm. I can run the tests through the gem by bypassing the pcm, i.e. the injector buzz test and the other multi function tests but nothing will link to the pcm itself.
greenskeeper
Full Access Member
90f250
Full Access Member
Yes they can, I dont know anyone off hand that has that but I will ask around
OK, Just want to mention this, I may be headed in the wrong direction, but (I've worked on IDI's in the brick and obs, then jump to an 03 6.0, so keep that in mind)
Since it sounds like it could be power related, you do have all the electrical connected correctly? We just recently had a thread that someone was working on a 6.0 and after they put "everything back together" they had power issues into the cabin. On the 6.0 Superduties (so this is an assumption on my part on the 7.3 ones) there are 2 wires connected to the drivers side battery positive terminal. The large crossover cable that connects both batteries together and to the starter, then a much smaller wire that bolts to the positive clamp that provides the power into the cabin. There is also a smaller wire from the passenger side battery positive that provides the power to the engine "stuff". Maybe you have something similar on the 7.3 cables and you are missing power that way. Just another option.....
I've found in troubleshooting different things that after pounding my head for days, sometimes starting back at, is it plugged in and is it turned on, helps because there has been a time the answer was it had come unplugged.........
Since it sounds like it could be power related, you do have all the electrical connected correctly? We just recently had a thread that someone was working on a 6.0 and after they put "everything back together" they had power issues into the cabin. On the 6.0 Superduties (so this is an assumption on my part on the 7.3 ones) there are 2 wires connected to the drivers side battery positive terminal. The large crossover cable that connects both batteries together and to the starter, then a much smaller wire that bolts to the positive clamp that provides the power into the cabin. There is also a smaller wire from the passenger side battery positive that provides the power to the engine "stuff". Maybe you have something similar on the 7.3 cables and you are missing power that way. Just another option.....
I've found in troubleshooting different things that after pounding my head for days, sometimes starting back at, is it plugged in and is it turned on, helps because there has been a time the answer was it had come unplugged.........
90f250
Full Access Member
Well.. I wish it was that simple. All of the battery cables are in fact connected. Lol. I really..really wish it was that simple in this case
If I had a 7.3, I'd run down there so we could do some "known good" swapping and testing. I'm not all that far away up 70..........
