So, my truck has had its check engine light on for a couple months now. I hardly ever drive it so I have not looked into it yet. Well, I am going to start camping again (now that the baby is a month old ), and I want to get the truck in tip-top shape to tow our trailer.

The truck is a 2007 F250 with the 6.0 diesel in it. It is a 4x4 with a 6" lift and 37" tires.

How the truck runs:
The truck seems to drive just fine, maybe a little sluggish, but not much. However, at idle (warm or cold) it does hiccup a little (misfire is the tech term I guess?). It normally idles around 700rpm and will sporadically go from 600-700 for a few seconds, then idle just fine for a while. (judging the rpm from the stock tach)
The truck does have an oil leak at the front of the engine somewhere that I have not diagnosed either yet. I don't know if the oil leak has anything to do with it, but wanted to put that in there just in case it matters. The leak is about 3-4 tablespoons on the ground a week.

Here are the codes:
I have the little cheap Actron CP9125 OBDII tester. It tells me there are 4 error codes that are displaying 3 issues.
P0675
P0683
P0460
P0683 p/d

Are the P0683 and the P0683 p/d are the same thing?

It says the issues are:
misfire
comp
egr


So, do I have 3 or 4 different problems, or is there one issue that is causing all of these?

 

P0683 GPCM Glow Plug Control Module to PCM Communication Circuit Open circuit, short to voltage, short to ground

This DTC^^^Above is Likely the Cause of the Following DTC I would Address this First

P0675 GPCM Cylinder 5 Glow Plug Circuit Open circuit, short to ground, short to voltage, glow plug



P0460 FLI Fuel Level Sensor A Circuit Open circuit, short circuit, fuel sending unit, instrument cluster

This shouldn't cause Misfire But IDK if goes into limp mode from it I think its more just a Gauge error somewhere or sending unit or wire and shouldn't cause a Drivability issue


Does the Idle SURGE happen all the Time??or just when Cold???
if Just when cold then could be Glow Plug relaited

If all the Time need to check ICP and ICPV and IPR%

 

In short Looks like you have a Wire harness problem


You will need a DVM to troubleshoot this


Check the GPCM Plugs really close Unplug and Plug back in clean them it Could Be Simple

 

It is all the time, even when it is warmed up it surges and misfires. I live in SoCal and it is 70* this week.

 

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Thanks blade. I'll check the items you mentioned (probably this weekend) and report back.

 

Got a question about testing the GPCM. I know here is the procedure:

TEST GPCM
Install an inductive ammeter on one bank at one of the two harnesses at the Glow Plug Controller Module (GPCM). You can get up to 200 A at first, but then should stabilize around 35-45 A. Check the other bank with the inductive ammeter. Both sides should read the same. If not, check the amps to each individual glow plug to determine which one (or ones) is bad. Each glow plug should draw 10-12 Amps.

My question is really about my clamp meter. Can this meter do this test?
Craftsman 400A AC/DC Clamp Meter 82369

The manual states "Do not put more than 1 wire inside the clamp at a time". However, each bank of the GPCM has like 6-7 wires in it

First off: is this the right meter to be using?

Second: Should I use the 400A setting or the 40A setting?

Third: Can I put all 6 wires in the clamp or will it hurt the meter?

Last: I tried to fit the clamp around one bank of wires, but couldn't make it fit with the turbo intake in the way. Can I unscrew the GPCM and temporarily move it a few inches to one way so I can better access the wires? Or does it need to be screwed down (mounted) as a ground?

I can get the clamp around all 13 wires, would that reading be helpful at all?

 

40 amp dc, no it wont hurt your meter, glow plugs are around 200 amps. Your meter would just show a ov or other overload symbol