I am trying to find a wiring diagram for a 96 e250 with a 5.8. This van was brought to our company as part of a merger, so I have little information on it. I was told it quit running one day and got diagnosed as a bad fuel pump. So they changed the pump and it still did not work. Rediagnosed as a bad pcm, replaced and still does nothing. The fuel pump relay does not turn on, my snapon solus can communicate with the vehical. The pcm relay was swapped for working relay and energizes when the key is turned on and has 12v on the power side. I would like a diagram of the pcm as I don think its turning on.

 

I got it sorted out. The egr differential pressure sensor was shorted internally. This was shorting the vref circuit, preventing the pcm from turning on. I will upload the engine wiring diagrams and pcm pin out diagram for any one in the future. The tps sensor is the only other 3 wire sensor that can short the vref. My scan tool would not connect to it until the short was taken care of.

 

Here are the wiring diagrams for a 96 econoline van with a 5.8

 

A huge takeaway here is IF a scanner cannot connect to the PCM first check would be EGR's TPS first?