Fuel pump not shutting off

[subliminal]

For the past week or so Ive had a large battery drain that would completely suck the battery drown to nothing in 2-3 hours. While the car battery was connected I was hearing something that sounded like it was running, Today I traced it down to the fuel pump. I pulled the fuse for the fuel pump and no more battery drain. I have been getting a P0089 code which is a fuel pressure code. What Im wondering is does this problem sound more like a pump, relay or fuel pump controller problem?

[Epic-A3]

Sounds like a relay failed. Have you tried switching relays or buying a new one to throw in to see?

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[subliminal]

This is a little weird, even if I pull the fuel pump relay which from the diagram I saw online said it was relay number 4 under the hood I can still hear the pump running. I also switched relays and its still there. It is only if I pull fuse 27 which is the fuel pump relay that I stop hearing it running and the draw goes away. Maybe this is the HPFP and not the pump in the tank

[subliminal]

Looks like the relay I thought was for the fuel pump actually isn’t. The diagram I had showed it as being one of the relays in the underhood fuse box but that doesn’t appear to be the case. Is it one of the relays behind the interior fuse panel?

[subliminal]

The diagram I have shows the fuel pump relay as relay 4 in the underhood fuse box, however when I pull that relay the fuel pump is still running and the only thing that will make it stop is either pulling the fuel pump fuse or disconnecting the battery.

If that is indeed the correct relay how is it even possible for it to be running with the fuel pump relay pulled?

[Epic-A3]

Pull each relay 1 at a time, see if any those make it stop. I'm scratching my head

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[Epic-A3]

It can't be the pump it self, something has to tell it to run. I assume the noise is coming from the gas tank area? So your battery is still draining?

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[subliminal]

Yes battery still drains, I have confirmed it is the pump. I pulled the back seat and can hear it running and it shuts off if I pull the fuel pump fuse, however I have pulled every single relay in the fuse box under the hood and it still runs unless the actual fuse is pulled.

If it’s running with the relay pulled would that mean it’s shorting to power somehow?

[Epic-A3]

That's what is so confusing. With out a relay closing and sending power to that area of the car... it shouldn't be running at all. I know as soon as you open the driver door, the fuel pump primes. I can't sort out how that would play in... if at all.

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[subliminal]

Unless the relay I’m pulling isn’t the fuel pump relay, I pulled relay 4 in the under hood fuse box, I actually pulled all of them to see if it would get it to shut off and none of the relays in the under hood box will make it shut off.

Maybe the fuse box has a problem and that relay slot is shorting out so it always provides power? I was thinking maybe a bad ecm or fuel pump controller but if it was either of those I’d imagine it should still shut off with the relay pulled so the only thing I can think of is I’ve been pulling the wrong relays.

[Epic-A3]

Wish I could more of a help, if I could get my hands on that thing with my volt meter.....maybe. I seriously doubt it's a bad ECM, anything is possible I guess but highly unlikely. If you had a couple wires bare and touch in the perfect spot I suppose it's possible to bypass the relay all together. It's possible to unhook and lift out the fuse box. Maybe a visual inspection will reveal something. Maybe a mouse chewed a wire, I dunno..lol sorry man. Keep digging.

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[subliminal]

Just to make sure I am pulling the right relay I have attached a picture of the relay I believe to be the fuel pump relay and circled it.


https://imgur.com/06ZaGQE

[Epic-A3]

That does look to be correct. I'll be back home tomorrow and I'll look at mine to double check

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[subliminal]

So went to the salvage yard yesterday to grab some parts and I picked up a fuel pump control module and I saw a car there with a new looking high pressure fuel pump so I grabbed that as well to have as a spare for $30

Anyways swapped out the fuel pump control module with the one I picked up at the salvage yard and the problem appears to be solved, the fuel pump no longer runs constantly and drains the battery. Just wanted to post the solution in case anyone has this same problem in the future

[Epic-A3]

Glad you got that bug sorted out.

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[chris86vw]

Anyways swapped out the fuel pump control module with the one I picked up at the salvage yard and the problem appears to be solved, the fuel pump no longer runs constantly and drains the battery. Just wanted to post the solution in case anyone has this same problem in the future

This is exactly what I was going to suggest you look into as I was scrolling. Glad you got it sorted.