No fuel pressure on my 08 sierra

Paul Kalstek · February 11, 2018

The truck wouldn’t start one day with no previous problems other that a tps issue (which I replaced ) talked to a few ppl and they all said bad fuel pump .i checked the relay (heard it click) I checked the ground on the pump and that was ok . Replaced the pump and still a no start condition with zero pressure . I originally suspected a fuel pressure regulator . Any ideas ??

Mike GMC · February 12, 2018

I believe the regulator is part of the pump assembly in 08. Did you replace the whole thing, or did you replace the pump in the old assembly? What are you getting for pressure at th rail?

Paul Kalstek · February 12, 2018

I replaced the whole thing . I still have zero pressure at the rail . When I turn the ignition on I hear the pump turn on

Mike GMC · February 12, 2018

What happens if you disconnect the fuel line from the rail and turn the key to on to start the pump? If no fuel come out, you may have a clogged fuel line. If fuel does come out, you may just have been air locked.

carnau · February 14, 2018

Your pump is probably controlled by the FPCM (fuel pump control module). Have run into this many times. Do you have any codes in the vehicle?

Here is the Schematic. A little more testing needs to be done but I am betting on a bad FPCM if you replaced the FP and it still has no pressure.

Here is the link to the module. - http://amzn.to/2Ep91zH

Mike GMC · February 14, 2018

If the fpcm is bad, would he hear the pump run with key on?

bubbanbrenda · February 14, 2018

8 hours ago, Mike GMC said:

If the fpcm is bad, would he hear the pump run with key on?

Yes, my fpcm quit, I could here the pump running, but no start, replaced it and had to have it programmed at a dealer. Also had a check engine light when mine quit, don't remember the code off the top of my head.

SpartanAutoworx · February 20, 2018

P069e most common code for bad FSCM.

New ones must be programmed to work.

Before replacement you need to check a few wires at the FSCM for proper power. The green and white wire is common for breaking along with a bad pcm. Diagnosis is key before spending any hard earned money for parts that might not fix the problem at hand.

get on YouTube and you will find a few good vids on properly diagnosing the FSCM.

SpartanAutoworx · February 20, 2018

Also 20759945 The part number for 2007 08 and 09 vehicles is on national backorder right now.

carnau · February 20, 2018

19 hours ago, SpartanAutoworx said:

Also 20759945 The part number for 2007 08 and 09 vehicles is on national backorder right now.

Agreed. But you can buy them on Amazon no problem! lol

http://amzn.to/2Ep91zH

Edited February 20, 2018 by carnau

Charles Potter · August 11, 2019

On 2/11/2018 at 5:34 PM, Paul Kalstek said:

The truck wouldn’t start one day with no previous problems other that a tps issue (which I replaced ) talked to a few ppl and they all said bad fuel pump .i checked the relay (heard it click) I checked the ground on the pump and that was ok . Replaced the pump and still a no start condition with zero pressure . I originally suspected a fuel pressure regulator . Any ideas ??

Did you ever figure out the problem?

Tim sliman · February 17, 2022

I’ve replaced fpcm fuel pump all new lines rails had new fpcm programed and now it only runs for three seconds then dies Ik fuel pump is good if I jump the power and ground from the plug for the fpcm to the power and ground for fuel pump truck runs but I have no power to the fuel pump fuse at all nothing I do I’ve trued back feeding power through the fuse nothing is working