Hello everyone, I am new to this forum thanks for taking the time to read my post. I am working on a 2006 hummer h3 with a 5 cylinder engine. When you turn the key to on everything comes on and works, but the fuel pump relay is rapidly clicking on and off and when you turn the key to the start position it doesn't crank. I already installed an ignition switch and followed the relearn procedure (the passlock/security is not the issue). I ran a jumper to the starter solenoid and the engine cranks, but will not start and the fuel pump relay continues to click. The relay is good. Has anyone ever encountered this issue? I am thinking it may be the pcm because the only time the fuel pump relay will stop clicking is when I remove the pcm fuse. any suggestions are appreciated, thanks.

 

Have you measured voltage into the relay? And out of it? What about voltage at the fuel pump? Tested fuel pressure at the rail...?

Im far from an expert, but sounds like a fuel delivery problem to me. That'd be the first system I'd start investigating.

Good luck