Ok I posted a question about a week age becuase of my truck not starting. I have check all fuses,relays,ignition wires all or good. The truck will turn over, everything in the truck works with the exception of the instument gauges(volt and gas) and roof cluster. I have tried a couple of scanners and all I get is can not communicate or can't see ignition. I thought that it might be the PCM or FCM(due to other posts about fuse box problems) so i replaced both with no results. I've down loaded a service manual thanks to others from the site. I've been racking my brain over all of the circuits that pertain to the PCM and Fuse box. I think i have it down to the AUTO SHUT DOWN RELAY/ENGINE CONTROL RELAY. If i jump out this relay the truck starts and works like a champ and everything is right with the world again. So looking at this the circuit it all goes back the PCM, I can't see this new PCM having the same problem as the one i just took out its brand new. Will they be damage if i jump this out temp? Or since the PCM doesn't see the ignition and will not trip this relay, what tells the PCM that the ignition is on. Any help would be great 3 weeks without my truck is starting to be a bi#&($CH

 

1 of my buddies had this problem and we replaced the fuel pump. Something in the pump was causing the asd to trip. Good luck.

 

checked out fuel pump it works fine

 

Im not sure what to tell you honestly. Best thing I can say at this point is to download the Service Manual from the links below in my signature and try to go through it and see what you might find