Trouble Code: P0683 - Glow Plug Control Mod to PCM Comm Circuit

kkanuck

LUV my T1N
I have combed through the site for this specific code, and have read all there is to find on it.

2 months ago, I had codes that identified I had a bad glow plug, which resulted in my changing all 5 Glow Plugs, and doing the MOD with external fuses on the Glow Plug Module.

Now today, I had it throw this code again, P0683.

My DAD computer is charging (battery was dead), so I will test with that soon, but I used the ScanGuage II to give me this code, and I then reset the code, started it and the code did not come back (right away anyways...I have yet to take her on another ride)

This code has the following meaning according to a post by Vic: Glow Plug Control Mod to PCM Comm Circuit.

IS this referring to a wire loom short perhaps? Anyone else ever have the same set of circumstances where change all, and this code reappears?

Cheers for any input...


Happy New Year to All!




Tibor
 

GEARS

2005 140WB standard roof
That is the same code I have and it's having trouble starting in cold weather.

:cheers:
 

GEARS

2005 140WB standard roof
Try disconnecting the engine coolant temp sensor, it's located on the thermostat housing.

I unhooked mine and now my van starts like a champ every time.

It is looking like my 1 year old coolant temp sensor has gone and **** the bed on me.

Let me know if your van starts up better with the coolant temp sensor unplugged.
 

kkanuck

LUV my T1N
Try disconnecting the engine coolant temp sensor, it's located on the thermostat housing.

I unhooked mine and now my van starts like a champ every time.

It is looking like my 1 year old coolant temp sensor has gone and **** the bed on me.

Let me know if your van starts up better with the coolant temp sensor unplugged.


So if I reset the Check Engine light, and disconnect the Thermostat sensor, then try starting her, and if the Check Engine light does not come on within 5 seconds of starting like she's doing now, that is the fault causing the light?

I will check....


Cheers
 

rbrennick

New member
Just searched this code because of a same problem (2004 2500)-
all glow plugs good, changed to a known good controller- same code thrown.
Did some diagnosing and found an open ground wire to the small plug into the controller-
spliced in a new ground wire to the plug (was not going to chase through that can of worms harness) and waa-laa- no CEL and proper glow plug operation.
I'd guess the ground wire is required for the internal coil to fire in the controller...

Just thought I'd share a happy ending (for me) to a similar thread that had no ending/solution.:thumbup:
 

220629

Well-known member
...
Did some diagnosing and found an open ground wire to the small plug into the controller-
spliced in a new ground wire to the plug (was not going to chase through that can of worms harness) and waa-laa- no CEL and proper glow plug operation.

...
Thanks for the information. Sounds like you were into the Data Link Connector to the ECM? Was the wire you found open a solid brown or a brown with a trace? If brown with a trace they may interrupt that ground for signal/information transmission? I didn't readily find a detailed schematic so I don't know the circuit configuration. These are just questions.

vic
 

rbrennick

New member
Hi Vic,
It was a solid brown wire; schematic shows going straight to a G100 chassis ground (wherever that is...) I'd guess the + hot wire of that same connector from the ECU tells the controller what to do and when to do it...
Rich
 

Attachments

InterBlog

Member
Old thread, perennial problem.

Question: This seems to be the most comprehensive P0683 thread. Has anyone solved a problem similar to the OP's in the past 7-ish years since this thing was active? If so, please comment.

Here is our sequence:

- Glow plug went bad, threw code.

- DIY replacement of all 5 plugs with MB-branded new ones (husband is a skilled DIYer - no problems with sticking, etc. - easy job).

- Code still being thrown after new plugs installed

- Husband replaced the glow plug control module after reading threads here

- Code STILL being thrown after new module installed

- I contacted Million Mile Sprinter, who noted that this issue seems to be fairly rare. He suggested cleaning off a grounding lug associated with the system

- Husband completed that, checked connections and wires in vicinity

- Code still being thrown.

I guess we are about to dive into it in more detail, but I wanted to see if anyone has additional wisdom to add, given the age of this thread. Thanks.
 

220629

Well-known member
Did you notice this in Post #10?

vic

Just searched this code because of a same problem (2004 2500)-
all glow plugs good, changed to a known good controller- same code thrown.
Did some diagnosing and found an open ground wire to the small plug into the controller-
spliced in a new ground wire to the plug (was not going to chase through that can of worms harness) and waa-laa- no CEL and proper glow plug operation.

I'd guess the ground wire is required for the internal coil to fire in the controller...

Just thought I'd share a happy ending (for me) to a similar thread that had no ending/solution.:thumbup:
 

InterBlog

Member
Yes, but I thought I'd ask anyway, just in case there was more info.

Sometimes when I do that, especially on old threads, three more people will speak up and say "Well, that didn't work for me, but this other thing DID work for me". That can save time.
 

hulagun

Haulin' A** since 1974
Interblog, any luck or news on this? My 2005 just threw this code today and the "CEL" is on on the dash. It starts and runs fine. I just want to get it fixed, so am digging thru the forum trying to learn what to look for, hoping it will be something relatively easy.
 

kkanuck

LUV my T1N
I ended up changing the controller (the modded one I did years prior) and the problem was fixed.
 

Hellshalfacre

2005, 2500
Hi friends, I accidently caused this code yesterday in my 05 2500 and just wanted to pass along what I was doing and how I fixed it. I had some really bad corrosion behind the drivers side headlight that I was trying to clean up, and I noticed the chassis grounds were in really bad shape. On my van there are 2 sets of 4 wires on loop connectors, and two 16g wires that used to fasten to the chassis ground posts before they rusted out. So I removed them to clean them up and they basically fell apart in my hand. I stripped what I thought was all 8 wires back to reconnect them to a new connector, but missed one wire. Didnt realize it until I went to start. Noticed a hard start and immediately got P0683. Went back and found my mistake and stripped the last wire back and reconnected. Problen solved. If you are seeing this code take a good look at your grounds behind the drivers side headlight.
 
B

billintomahawk

Guest
Hi friends, I accidently caused this code yesterday in my 05 2500 and just wanted to pass along what I was doing and how I fixed it. I had some really bad corrosion behind the drivers side headlight that I was trying to clean up, and I noticed the chassis grounds were in really bad shape. On my van there are 2 sets of 4 wires on loop connectors, and two 16g wires that used to fasten to the chassis ground posts before they rusted out. So I removed them to clean them up and they basically fell apart in my hand. I stripped what I thought was all 8 wires back to reconnect them to a new connector, but missed one wire. Didnt realize it until I went to start. Noticed a hard start and immediately got P0683. Went back and found my mistake and stripped the last wire back and reconnected. Problen solved. If you are seeing this code take a good look at your grounds behind the drivers side headlight.
When I bought my van it was a mess.
The PO had mental health problems.
I was confronted with a new battery lashed to the firewall and poorly held.

The PO blew up the old battery and the acid ate the battery platform and ran down on the grounds below. A mess. I cleaned out the corrosion and built a new platform for the battery out of outdoor plywood, repainted the inside of the engine bay with some old house paint and extended those grounds up to the firewall ground.

No problems since. The battery is bungied to the new platform with trucker grade bungies and has stayed solid.

This was my first T1N repair back in the dark days before I knew there was a Sprinter forum.

bill in tomahawk
 
Last edited by a moderator:

Hellshalfacre

2005, 2500
Yeah Bill. I suspect the same happened to my van at one point. I think those grounds get overlooked sometimes. I'm not sure what else is on that ground stack besides headlights, blinkers, ground for Gp MOD and maybe Espar heater ground if the Van is so equipped? In any case, worth a look if anyone is getting P0683.
 

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