I bought my 2000 Excursion back in March. It's had the CEL on ever since I bought it with the P0683 code. Lately I've been having some no starts on cooler mornings. The truck will crank, but not start. I can only try to start it about 2 or 3 times before the batteries are spent and I have to recharge them before trying again.

I finally replaced the GPCM this week, but am still having the same symptoms and code.

Today I did the 8 hour long 50 cent mod thinking that might fix it. When I got done, the truck cranked up, ran like crap for 2 or 3 seconds then smoothed out. No CEL! Problem solved right? Nope, I shut it off and tried again - got the CEL. Ran codes and P0683 was back. I tried cranking it again and it wouldn't start. Then the batteries went dead.

Now after a battery recharge it's a little hard to start, but did start twice, but is still throwing P0683.

On top of it all, I'm now also leaking oil from the dipstick tube connection.

What should I do now?

 

Look at this for some reference

https://www.ford-trucks.com/forums/1...l#post14125824

 

That 0683 is ONLY an alert for failed communication between the PCM and GPCM. It comes down to one wire, the GPCM or the PCM. You have already ruled out the GPCM. I would be checking on that wire. I can get you the color code and which plug it is on tomorrow if you don't have the wiring diagrams. Could very likely be the same solution gramicko has found on his truck, or you could have a loose connection (pin inside the plug on either PCM or GPCM end) or broken/shorted wire. That wire will also run through the giant main plug on the driver's side valve cover as well, so that is another connection to check.

 

That wire color would be much appreciated!


​​​​​​My red gaskets in the connectors looked fine. I did however notice the green connector won't lock into place. I'll have to mess with it more tomorrow and also follow that wire.

 

Take those red dust shields all the way out and plug it back in. See what happens.

 

Sorry, I forgot to add, I did remove the red dust shield on the green connector that won't click into place. It still wouldn't click into place. I'll check tomorrow for bent pins or some other obstruction. The connector feels like it's going in all the way, but just doesn't snap. I'll start there tomorrow.

 

When troubleshooting my GPCM, I like to take it off the bracket. 2x10mm nuts and it is in your hand and much easier to plug and unplug.

 

Here is some more information on the P0683: [LINK]

Issue 1: It sounds like your batteries and/or your battery connections are toast. It's hard for glow plugs to warm the engine up without serious juice.





Issue 2: I don't trust the 50-cent mod - it has failed on me, and I've seen it fail for others.





Some have been skeptical that the image above is a loose connection, but the multimeter doesn't lie. The glow plugs and injectors need to be ohmed out individually if you suspect a bad connection, and to verify a fix. (UVCH link in my signature covers the injectors)

Once all the basics are covered, you can look into the feedback line from the GPCM to the PCM (pin 8 on the PCM, pin 41 on the 42-pin connector). My book shows a white wire with a light green trace (2002 - my 2000 book doesn't show the GPCM). Have you cleaned all the electrical connections with Deoxit or at least electrical contact cleaner?

 

Rich is correct about the wire color. It is white with a light green stripe.

 

Saga continues:
I didn't get to mess with it last night since it was Halloween. It sat all day- started it last night to go out and it started right up (it was about 80 degrees outside.) I turned it off until time to leave and then it wouldn't start again - the batteries were dead. Threw it on charge for a few mins and got it started. We went trick or treating and it was fine, but hard to start back up twice once when we stopped a few times.

This morning it started right up and ran for 20 seconds before dying. I started it again and it ran like crap - knocking and sounding like not hitting on all cylinders.

Parked it for the day and just put on two brand new batteries (old ones tested bad). It started up, but is still making a knocking sound and running like crap.

For now, the P0683 code has been cleared and didn't come back on. I'm still a little leery of that too, but I'll watch it over the next few days.

Any ideas now on why it won't run? I did let it sit and try to clear itself up for a few seconds, but I either got worried and turned it off, or it would die on it's own before clearing up.

I also tried unplugging the ICP to see if that would reset - no difference.

 

UVCHs. You need to check them out. What you are describing is a classic symptom of them coming loose. Bad connection to the GPs and the injectors=crappy running or no start.

 

I cleaned the driver side 9 pin connector (on top) and the 42 pin big connector (which had a slight bit of corrosion in it) on the drivers side and she's back alive again!

I'm still getting P0683 intermittently, so this weekend I'll be back to tracing that white wire with the green stripe.

 

That white/light green wire for the P0683 is in the rear most plug on the GPCM. Easy to see it without even unplugging it.