[Nathan02psd]

I have an 02 F250 that had a rough idle, glow plug light stayed on, it had a leak from the hpop so I changed it out with a Bosch and new IPR reconnected everything and it was lopping super hard. Ran it for 40 mins idling. Never got better. Turned it off and couldn’t get it to start after that. Pulled the code up said PCM wasn’t communicating with GPCM. Changed all glow plugs & harness (from ford), ICP sensor, changed the GPCM (ford part) Checked all my fuses, still nothing. The glow plug light is still staying on. The code is now reading P0676 for glow plug #6. Took the valve cover off checked all my connections put it back on. Cleared the code. Same thing. No start. Anyone have any ideas? Next thing I was considering was is a broken wire in the harness, or the glow plug solenoid is bad by the fuel bowl?

 

[NoRalPh]

What is it you're using to retrieve codes? You know we need special sw with both the Ford Propriety and Diesel Specific library of codes in it. Plus, we are not, specifically, OBD-II but rather a variant called J1850. For those reasons your scanner might not be up to giving you a full, proper, scan.

 

[Nathan02psd]

A innova reader. My buddy had his Snap-On reader on it which wasn’t communicating with the PCM but after replacing PCM I’ve only used the cheap innova reader with OBD-II. I will see if he can run another diagnostic with his. Thank you.

 

[NoRalPh]

Here's my usual Scanner advice


If you're gonna keep & maintain the truck yourself I strongly suggest you get access to the special scanner software you need to do it.

To retrieve most of the codes you'll need to help and even do some testing look at the FORscan Lite or TorqueApp (you add an Android device and Blue Tooth Adapter for @ $30) OR the Windoze version with a USB adapter. I like this one for BT Android -> Amazon.com: Wireless Bluetooth OBDII or OBD2 Reader Scanner Tool for Android (NOT iPhone/iOS Compatible) Diagnose & Fix Check Engine Light by BAFX Products: Automotive

Just a few years ago you needed to buy a professional scan tool because our trucks need to have a scanner with a Library containing both the Ford Proprietary AND the Diesel Specific codes in it. Add to that, our trucks are Not, specifically, OBD-II so the Generic scanners the Auto Parts Stores have are of little use to us. But today there are some very good App based tools, that are close to what the pro tools do, for fraction of the cost.

Ford SuperDuty Diagnosis on the Cheap

How To: Super Duty Diagnosis on the Cheap! This will be a multi-part write-up, covering how to diagnose, monitor, and run tests on Ford Super Duty Trucks, focusing on the Ford 7.3L Super Duty as that is the truck that I own, but these tools work for all Super Duty Trucks. Warning: Some...

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