No power going to the fuel pump

[ninerstatus49]

01 grand am gt 3.4, I tested the gray power wire at the pump, no two second prime, no power. all relays, and fuses are good. What could be the cause? Any help, please.

[thephantom1492]

What I'ld start to do is test for 12V at the relay contacts, then check for the relay coils contact for a 12V prime... if you do get the 12V for the contacts, and that the coil do get prime power... it mean that the problem is between the contact and the pump.

[Tech II]

Just to elaborate a little more on what thephantom said:

Put your finger on the f/p relay.....does it click when you turn the key to on? If it doesn't,

With the key in the "on" position, remove the fuel pump relay.....there are four legs or circuits........two of the legs should have battery power to them.....there are two other legs......on is the leg that goes and delivers power to the f/p....the other is the "control" circuit from the PCM.....when the PCM grounds the "control" circuit, this turns on the relay and closes the contacts to provide power to the f/p....so if the relay is good, and it doesn't click, and you have power on two legs, then the PCM is not grounding the relay or the control circuit is open....

Has the car been scanned for BCM and PCM codes?

[ninerstatus49]

This makes alotta sense. After doing more looking around, I noticed a ground wire that feeds into the cab was damaged, I fixed it, but could this have caused the pcm to short out?

[thephantom1492]

I doubt it, but without knowing which one preciselly it's hard to say no. But I hightly doubt it.

[ninerstatus49]

Is a way to check the pcm? Can i test it?

[thephantom1492]

sure there is a way, just use a test light on the right pin I don't know which one it is....

[Tech II]

One thing I want you to try:

Have someone crank the vehicle while you spray carb cleaner into the intake.....if it starts and runs as long as you spray, we know it's fuel.....

Don't know where you live, but if it's below freezing, you may have to squirt the carb cleaner into the intake and let it sit for awhile....several times, before cranking and spraying at the same time...

Also, have seen problems with the UBEC's.....tap on the relay center under the hood will cranking, and try pulling on the harness to it while cranking....

[ninerstatus49]

Yeah ive done that, and it starts right up with starter fluid. Oh, and on my last reply I didn't mention that the broken ground wire leads to a ground block, that leads to the cab. Its a thick wire. Any help. Thank you guys for everything by the way.

[ninerstatus49]

Judging by what I've read, I'm pretty sold on the fact that its most likely the pcm. So I wanna buy it. But... my repair manual says that there is a reset from the dealer necessary, in order to achieve greatness! Just kiddin, to complete the fix. My question is, is that true, or, is there another way? Please bro's, this fight, with this car, just got personal! Haha, and I really wanna win, and share the knowledge.

[Tech II]

BEFORE you replace a PCM, you need to attach a scan tool, to see if you can communicate with it....if you can, and if there are no codes(PCM or BCM), then you need to check that control circuit to the fuel pump relay....

[thephantom1492]

All PCM MUST be programmed by the dealer. Putting a random one in your car will not work at all. They say it's for theif deterant... I say it's vendor lockin.

Another problem is that it is said that once a module is programmed, it can't be reprogrammed. I do not know if this is true or only dealer propanga however.

Do check everything BEFORE you get a new module. I doubt it's a module issue.