[TCruzan]

Does anyone have a diagram for what the fuses go to? I was driving the truck, just died and would not start. I found that the 1st big fuse was blown. I repaced it, the truck ran for 2 min, then blew it again. I got the P1668 error code as well. Any ideas????

Thanks,

 

[circletrack97]

1668 PCM/IDM PCM-IDM diag. communication error Communication on EF (Electronic Feedback line) Open/shorted EF or FDCS, open IDM ground

 

[JimTJr]

It sounds like you need to look your harness over good, the one to the PCM, and IDM. (If it says open/shorted on the one, but it seems it says "Open IDM ground" that would not cause a fuse to blow, you have a short to ground someplace. Nothing to do but start looking really good first. (A great visual inspection can do wonders, even in electronics....)