what the title says

my truck has no spark and the rpms do not register when cranking the truck so I replaced the Crank sensor and still the same thing, I know fuel is going to the cylinders but the thing is just not sparking and it I am almost positive it is not the coil packs because they could not have gone out overnight(literally)

but anyways since I am almost sure it is the computer (unless there is a relay) how can I tell if it is really that without buying a new one

 

Does the CEL come on at ignition power on? If not, the PCM probably isn't getting power.

Check fuses F24 & F30 in the under-hood box and the PCM Power relay.

If either fuse is blown, there are common reasons.

 

Some years ago, I had a similar problem. Fuses and everything was okay, but there was a fuseable link that went out making the PCM not get any power. It would crank all day, just never start.

 

@kingfish where was the fusible link

@projectsho what number is the pcm relay

 

Sorry, don't know. As the vehicle was under warranty, I just let the dealer deal with it. Just got the explanation.

 

hmm I guess I will try and get it out of the dealer

 

I dont have any idea but it may be a last resort fuse actually inside the CPU.

 

did you check all your fuses?

 

Check the fuses and relays under the hood of the truck. The pcm relay is one of the three larger ones ( the others are the fuel pump and horn) and you can swap them around to check them.

 

Well I started to check all of the fuses and I started inside and a 30 amp fuse (numbered 30 on the little chart thing in the fuse panel) was blown so I replaced it and I am charging my battery and hopping that that will have been the problem

 

SUCCESS!!!!

turns out it was that fuse...man that sucks that my truck was brought down by something smaller than a nickle

however my truck still does not start up immediately when I turn the key what happens is the starter relay clicks but the starter does not turn I may need to pull my starter and clean it(it looks to have a lot of oil on it) and hopefully that will solve my problem

 

(DOUBLE POST, Stupid computer)