No voltage from PCM fuel relay trigger
 

This came out of nowhere. I've had it hooked up for several months now and it's worked really good. Now I'm not getting any voltage from my PCM trigger to my fuel pump relay. If I wire around it, the fuel pump kicks on. I've been all over checking wires, fuses, grounds, etc.. and this is baffling me. In a desperate measure, I tried replacing the crank sensor and still nothing. I've read where guys have encountered this kind of issue theirs wound up being wired wrong or a grounding issue. I haven't changed anything up, so I'm at a loss.

Re: No voltage from PCM fuel relay trigger
 

This is a little out of my league but I kinda understand it. I checked google and found this site with the same problem you are having so I am pasting the link for you.

http://www.pirate4x4.com/forum/gener...fuel-pump.html

Re: No voltage from PCM fuel relay trigger
 

I think is issue is one of two places. Either an ECM issue, or a wiring issue.

It sounds like you have the wiring figured out. Should have 12 v fused power to relay, good ground, wire to fuel pump, and the ECM signal.

On the ECM side, there could be something that is preventing it from powering up the fuel pump. Like a fault code. Might want to try checking codes, then resetting the computer by disconnecting the battery.

Re: No voltage from PCM fuel relay trigger
 

Well I got it going. Cannot tell you what was wrong as I didn't replace anything. The wires I cut while trying to diagnose the issue, I re-soldered and heat shrinked and all of a sudden it's working again. Makes no sense. I've taken my time and carefully inspected every wire, no cuts or slices in any of them to ground out anywhere...I was fixing to get another PCM or just put the fuel pump on a switch, but now it's fixed. Thanks for the help anyway fellas.

Re: No voltage from PCM fuel relay trigger
 

If there is a problem with the ignition the ECM won't kick in the fuel pump.

Re: No voltage from PCM fuel relay trigger
 

Yeah, I read somewhere that if the crank sensor goes bad that the PCM won't kick the fuel pump on. I replaced it and nothing changed. I could hear the throttle body do it's deal when the key was on, so I'm assuming my PCM was still getting power.