P0670 after changing glow plugs. 2002 excursion
Thread Starter
|
Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
P0670 after changing glow plugs. 2002 excursion
Been getting a p0673 code(glow plug cylinder 3), so I changed all 8 glow plugs this weekend. After doing that now I'm getting p0670 gpcm communion issue. What did I do wrong or what's my issue? I went from one glow plug being an issue to the gpcm being an issue. Any input on this anyone know anything about this system?
Thread Starter
|
Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
Well we had a no start this morning when my wife wanted to leave for church, so I'm guessing the glow plugs aren't working. I'll have to investigate further when I get home. Anyone have a good trouble shooting link for this system. I'm familiar with the relay but not this all that well. Only issue I've had is when I replaced the glow plug module a while back. (Yes genuine ford).
Posting Guru
Joined: Jul 2017
Posts: 1,236
Likes: 2
The controller does add a complexity compared to the simpler relay, but some of the trouble shooting does not change.
Disconnect the valve cover harness on each side and ohm out the glow plugs. From memory, each should be in the range of a half ohm to two ohms.
It may be as simple as one of the connections to the UVCH not being tight. Certainly, I would look at the work just completed before looking for a new coincidental problem showing up right after.
Disconnect the valve cover harness on each side and ohm out the glow plugs. From memory, each should be in the range of a half ohm to two ohms.
It may be as simple as one of the connections to the UVCH not being tight. Certainly, I would look at the work just completed before looking for a new coincidental problem showing up right after.
Thread Starter
|
Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
I have not had time to look into it more yet, as I am at work today. But verifying I understand this system correctly.
The GPCM controls all eight glow plugs and will trip a CEL if there is an issue with any one of the glow plugs then sends a code of p0671-p0678 dependent which cylinder is the culprit. There is also p0670 and p0683. With 0670 being fault in the control line for GPCM and 0683 being failure in diagnostic circuit for GPCM. so with that said my assumption is if I didn't get one plugged in solid or something of that nature I'd get p0671-p0678 depending which cylinder is the offending culprit. Am I assuming this correct?
So if I am assuming correct my issue is in the wiring going to the GPCM? I did have everything apart up there as I rebuilt the fuel bowl and resealed the HPOP while I was in there. Maybe I disturbed some wiring or something. Is there a fuse that runs this. Doubt I blew a fuse because I never get lucky like that. I do get glow plug reading on my scan gauge 2 of 99% but I'm thinking that's coming from the PCM not the GPCM since I also get that from my truck without the GPCM. But that does tell me at least it appears the PCM is sending the command for the glow plugs. Any one have any insight or comments to add?
The GPCM controls all eight glow plugs and will trip a CEL if there is an issue with any one of the glow plugs then sends a code of p0671-p0678 dependent which cylinder is the culprit. There is also p0670 and p0683. With 0670 being fault in the control line for GPCM and 0683 being failure in diagnostic circuit for GPCM. so with that said my assumption is if I didn't get one plugged in solid or something of that nature I'd get p0671-p0678 depending which cylinder is the offending culprit. Am I assuming this correct?
So if I am assuming correct my issue is in the wiring going to the GPCM? I did have everything apart up there as I rebuilt the fuel bowl and resealed the HPOP while I was in there. Maybe I disturbed some wiring or something. Is there a fuse that runs this. Doubt I blew a fuse because I never get lucky like that. I do get glow plug reading on my scan gauge 2 of 99% but I'm thinking that's coming from the PCM not the GPCM since I also get that from my truck without the GPCM. But that does tell me at least it appears the PCM is sending the command for the glow plugs. Any one have any insight or comments to add?
Posting Guru
Joined: Jul 2017
Posts: 1,236
Likes: 2
I think you do have a good understanding. Actually sounds like an excellent understanding. Since you had other things apart on top, I think you are on the right track for something being loose. Still would ohm out the glow plugs for piece of mind and to completely eliminate the glow plugs and UVCHs from further troubleshooting. Also to confirm your prior work in that areas is complete, and as a basis for future troubleshooting assuming you keep the truck another 100 thou or two,
That will then point to some of the other wiring related to the controller. Which you are already considering. You could just jump ahead to that, and come back to verifying the other work at the end.
That will then point to some of the other wiring related to the controller. Which you are already considering. You could just jump ahead to that, and come back to verifying the other work at the end.
Thread Starter
|
Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
well I have the p0670 figured out. The green connector on the GPCM wasn't pushed on all the way. Now I'm getting a p0675 which is glow plug cylinder 5. I'll ohm that out when I get time tomorrow. Should it be a 0 ohm reading from the pin on the GPCM plug if I use the battery as my ground? Went from cylinder 3 issue to cylinder 5. Can't ever get a break. Lol.
Trending Topics
Posting Guru
Joined: Jul 2017
Posts: 1,236
Likes: 2
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
Thread Starter
|
Cargo Master
Joined: Dec 2005
Posts: 2,296
Likes: 11
From: freeland, mi
Ok I'll check them and see. I would find it hard to believe I have bad brand new glow plugs but maybe a UVCH issue. We will see I'm sure. Thanks for the help so far. I will try to keep this updated for anyone who searches in the future.
Logistics Pro
Joined: Oct 2011
Posts: 3,953
Likes: 120
From: Mcdonough, GA
double check all the pins for the uvch connections for condition, burnt, etc
Thread
Thread Starter
Forum
Replies
Last Post
ranagent
1999 - 2003 7.3L Power Stroke Diesel
15
Sep 8, 2015 07:37 AM
huntharbor
1999 - 2003 7.3L Power Stroke Diesel
16
May 1, 2007 01:31 PM
kellerkathleen
1999 - 2003 7.3L Power Stroke Diesel
1
Mar 1, 2003 12:55 PM