It's me again, anyway I got my FICM in but the truck is still starting hard, voltages are good no codes, last night I plugged the block heater in and it cranked right over and fired and idled smooth, before it would blow smoke was hard to tell but looked mostly white, is there a way to check the glow plug control on an 06 F350 PSD, kinda thinking it is either that or the plugs themselves, so not looking forward to changing the GP if they are bad, SGII shows no codes or pending codes either, Again Thanks for any info on this.

Andy

 

The system checks are pretty good for the glow plug circuit, and if you have a bad plug or bad GPCM, it will almost always show a DTC and then a CEL. You can test them yourself with a clamp style amp meter to see if they are getting power, and you can test resistance through each plug at the GPCM connectors.

I think all of that would be a waste of time, given your symptoms.

 

Bpounds, so if I am inderstanding what you wrote, I should just change the plugs then? Or where you getting at a different problem?

 

No, I am saying that if your glow plugs were not working, you would have a code. The diagnostics are pretty good for the glow plug system. Something else is causing your problem. Maybe just injector stiction.

 

I agree with Bill that glow plugs likely not the problem, but if you want to check them out here is some info. He's talking about one side of the engine, the other plug would be for the other side. Also note the OP did have a code set:
Glow plug test

09-18-2011 | 11:00 PM
m-chan68
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.

 

My experience was just the opposite. I was blowing white smoke at startup with rough idle. Started fine when plugged in, I checked the glow plugs and found 4 bad plugs. No CEL. I replaced all 8 with harnesses and the rough idle stayed. No white smoke anymore just black changing to greyish. FICM tested bad - replaced that and all is well now! Smooth easy starts.

Cheers