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-   -   P0672 #2 glowplug code (https://www.ford-trucks.com/forums/1574628-p0672-2-glowplug-code.html)

mrwalleyeman 03-03-2019 07:02 PM

P0672 #2 glowplug code
 
So about a year ago I posted for some help on the P0672 code, and you guys came through. I was walked through the process and succeeded for the most part.
I changed out the the glow plug and replaced the wire harness for it, but still got the code after clearing it. I then replaced the glow plug control module and cleared the code, and still have the code.
Life got a little hectic this last year with some medical issues with my wife and she had to have a few surgeries from a different type of cancerous tumor in her breast (fortunately everything is good
now so far). I did try for a little bit this morning to search to see where I needed to go from here to get this issue figured out. I found that I needed to do an ohm test where the wire harness plugs into the GPCM, When I changed out the GPCM i didn't look black or green plugs that go into the GPMC, so I don't know if that could still cause the issue or if I need to look elsewhere. So from the glow plugs the harness plugs into another harness up near the ficm if I remember correctly, then from there I have no Idea where the wires go so I can look for chaffing or something along that lines. I would love to get this figured out so my truck will start easier and not be so dang hard to start without plugging it in and then buck and snort for a minute them smooth out.

Any help or advice would be awesome.


xcrsp440 03-03-2019 09:53 PM

Search for Diesel tech Ron videos on glow plugs and testing. Really simple troubleshooting with a meter or test light. Where did you get 5he GPCM? Some aftermarkets don5 work well.

mrwalleyeman 03-05-2019 02:20 PM

Thanks for the Info XCR, I will check out his vids. I got the GPCM at Oriellys, and believe it may be a Dorman brand, (may be part of my issue). I did keep the old one though. Ill be able to actually start working on it this weekend as the weather is actually warming up.

xcrsp440 03-05-2019 09:43 PM

There have been a few reports of a bad aftermarket GPCM. I found a used OEM on eBay pretty cheap.

mrwalleyeman 03-06-2019 06:40 PM

So I just did an ohm test on the #2 glowplug and it ohm-ed at 1.1, I then went ahead and checked all the others since I was in there and all of them Ohm-ed out between .9 to 1.3, but for some weird reason when I tested number 5 it didn't do anything at the bottom of the little screen it just showed a battery icon on my multimeter. I did do the test from the Green and Black plugs that plug into the GPCM, and the glow plugs were still attached to their wire harness. So now I am totally confused the code I get is P0672, which from my understanding is the #2 glow plug But the number 5 gives me no reading. I also decided to put the old GPCM back in just to see and still get the code. Anyone have some ideas on where to go from here.

xcrsp440 03-06-2019 11:01 PM

What are you using to read the codes and when was the last time you looked for any?
Glow plugs codes may take several key cycles before they clear or appear.

I would try try clearing the code and seeing if it returns.

I am assuming your #5 plug will need replacing based on what you describe from testing.
Curious now, what was the location of the glow plug you changed? Passenger or driver side?

mrwalleyeman 03-07-2019 01:50 PM

Its an Actron code reader. I replaced the front drivers side GP. I checked codes before I did the ohm test, and then checked again about an hour after, with a few start engine cycles. Im am guessing I will have to change the #5 GP also. I have had Oriellys use the code reader they use to scan for codes and the code comes up the same. I have tried almost every week to clear the code, and it will clear and I won't have a check engine light until I start the truck again, then the check engine light comes back on, read the code and its the same P0672 code. Again thanks for the help xcrsp440

xcrsp440 03-07-2019 03:45 PM

Odd, we had three glow plug codes, but no check engine light came on. The truck had two plugs that were out of spec and had to replace the gpcm to get rid of the remaining code.
i wonder about the code reader. Not sure how good the actron is at reading everything. Some only pick up generic or obvious codes.
Perhaps there is something else besides glow plugs going on.
There is a nice cheap app called Forscan that will read every sensor or code. Just need to buy a wireless obd adapter that works with your device.

mrwalleyeman 03-08-2019 01:09 PM

I tried a code reader my wife bought that's a bluetooth code reader and it came up with no codes, its a micro mechanic app. Its just odd that one code reader gets the P0672 code and a different one does not. This is just really weird. Im going to replace the #5 GP and wire harness this weekend, then I will update.

xcrsp440 03-08-2019 10:05 PM

Like I mentioned, some of those code readers are not very good for in depth interrogation of the vehicle. I mentioned one that is proven.
Cant help much without reliable data. Perhaps a new glow plug will clear the check engine light, but maybe it won’t.

mrwalleyeman 03-13-2019 07:22 PM

Ok so I bought a better code reader, the code that comes up is P0672 #2 glow plug circuit failure. Now Like I said before I did the Ohm test and all of them ohm out at .9 to 1.3 ohms, except #5 i get no reading. So now I am still in the same situation as before not knowing where to go. I don't see how the #2 GP circuit could be bad if it ohm-ed out just fine (don't remember the exact reading for it but it was between the .9 to 1.3). I am going to change out the #5 GP and see what happens. Now I guess I should ask this when looking at the GPCM there are the green and black plugs, which one is supposed to go where does the green go to the top or does the black one?

xcrsp440 03-14-2019 03:30 PM

Black on top.

mrwalleyeman 03-16-2019 06:17 PM

So I got the passenger side GP changed out. the hardest part of that was getting the wheel liner out and keeping the vacuum thing up and out of the way. when i got done i fired the truck up and no codes at first because i had the battery unhooked. well then the second time i fired it up i got the check engine light again with the same P0672 code. well then I starting lookin as good as could at the drivers side and first thought did I actually change the right GP. Then for some stupid reason I saw that the wire harness on the #4 GP was seated in place really well and from what I could tell so were the others. I then fished my hand down in there at each GP and they all seemed to be seated in except for the #2 GP. I gave it a little push and I felt it slide in a bit. I went to fire the truck up and still had the check engine light turned the truck off then read and cleared the codes, fired the truck up a few times and NO CHECK ENGINE LIGHT, wooohoooo i figured out the problem that's been haunting me for a while. Thanks for the help xcrsp440 I really appreciate all the help.

xcrsp440 03-16-2019 09:43 PM

So it needed #5 replaced, but #2 was because the harness wasn’t seated far enough!
Glad you figured that out, hope cold starts get better for you.

mrwalleyeman 03-16-2019 10:04 PM

Yes the #5 was bad I did an ohm test with it out and it gave me the same reading as before. It was just weird that I never got a code for #5 though. I did feel pretty dumb for not double checking the harness on the drivers side, I am usually pretty good at double checking things.

I will find out tomorrow on my cold starts, hopefully it is better. Again thanks for the help xcrsp440.


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