[adirondacktow]

I have a 04 F550 6.0. I am getting codes P0671-678 (glow plugs cyl 1-8). Tested all glow plugs just to be safe and all are good like I assumed they would be. Replaced GPCM as advised by Ford dealer. Still not fixed and still throwing all same codes. Testing resistance on all wires as per alldata today. Has anyone else had this problem?

 

[adirondacktow]

anyone have any ideas?

 

[dieselpower8]

how do u get the clip off to test the glow plugs its giving me a hell of a time?

 

[adirondacktow]

the plug on the intake has a little clip locking it together. the connectors on the plugs just pull off and the connectors on the glow plug module unclip very hard. Try to push in with a screwdriver while pulling on the plug. It worked for me

 

[dieselpower8]

alright thanks

 

[adirondacktow]

took it to the dealer. they said it needs 8 glow plugs and both harnesses. I think they just said it needs that that because that is all that is not new. I guess Ill do that and see if its better