Does anyone know if this means glow plug failure or gp module or relay failure? It is on the #5 cylinder. Also can anyone direct me to where the relay and module are or what tech bulletin has the info? Thanks in advance
Disconnect the four-wire connector to the passenger side glow plug harness (the one with the red lock tab). Using your ohm meter (and the appropriate scale if it doesn't have the auto-range feature), connect the black lead to the passenger side negative battery cable and the red lead to each of the four cavities on the glow plug harness end. You should obtain readings between 0.5 to 2.0 ohms on all four circuits (cylinders #1, #3, #5 and #7). If all four yield similar readings, the cause of your P0675 is either a high resistance/open circuit in the main engine harness between the glow plug control module and bank #1 glow plug harness, or the glow plug control module itself (most likely scenario). If you do obtain either a high resistance or OL reading for cylinder #5 glow plug circuit, replace the glow plug harness on that bank (because it will ALWAYS break during removal no matter how careful you are) as well as cylinder #5 glow plug (or cylinders #1, #3 and #7 as well since you have the harness removed). If diagnosis determines #5 glow plug/ciruit faulty, remove the passenger side inner fender to gain easy access to the glow plugs and its wiring.
WOW! Great information and assistance!! I hope it is just the module as it is the easiest fix for this novice to working on diesels. Runs great if i plug in the cord for a couple of hours. It is a 2005 F-350.
I guess i could just keep plugging it in before i drive it cuz it runs great if the block is warm. Starts quick and runs great (now that i have a great tune in her) when it is warmed up. It just keeps nagging at me like my ex-wife. Ha!
TomCat - I am a regular guy with not much experience fixing trucks. I had a similar problem - #8 glow plug. I replaced the GPCM myself - that is easy - hardest part is wrestling with the boost tube to get it out of the way. It is easier with stock tubes (mine are aftermarket). It turned out to be the glow plug itself. I never got around to doing this myself - like you, I put it off for 4-5 months, then when something else broke, I had them fix that too.
Was that glow plug fix expensive? I changed the GPCM myself and like you said it was pretty easy. If it is too much i will have to just keep plugging it in before i have to use it. A bit of a hassle but money is money and if it ain't there it ain't there. Sounds like a Yogi Berra line. Ha
the glow plug fix was reasonable - glow plug was $10 and one hour labor. The harness was not broken luckily (probably b/c I have a low mileage truck) - it gets brittle with age. It would be more if that needs to be replaced, probably 2 hr labor and $150 in parts (harness and 4 glow plugs).
Wow that is not bad at all. I wish i was in FL. to get it done that cheap. Dealers in Texas tend to rape its customers on price. I need to find a mechanic that wants the extra money on the side to do it. I may be able to get it done at FL. rates that way. Ha Thank you for your assistance with this.