P0087 and P3045. Car randomly dies. Dealer ran some tests. Any advice appreciated!

[nagrover]

Hello Audizine. First post.

A brief background. My brother-in-law has a 2011 2.0 TFSI A4 with 220,000 KM's on the clock.

Lately his car has had a number of issues such as a failed timing chain tensioner and broken valve spring.

He has always had his car dealer maintained up until the broken valve spring (I replaced that... fun!).

Getting to the point, last week his car died while driving to work. It was towed to the dealer. Once the mechanic looked at his car, it fired up just fine. The dealer ran some tests, wrote up a report, and my brother in-law drove home. It has since died 3 more times in a week while idling on his driveway. So far, the symptoms can be summarize as follows:

Symptoms:
- Car dies randomly while driving or sitting stationary and idling. Engine stops running.
- The car will not start once it dies. The engine cranks over freely.. and endlessly.
- After sitting for a while (usually overnight) it will start but will then die again after driving/idling a short while.

Dealer assessment (spoiler, seems to be fuel related):

Client was driving, engine struggled, then shut off. No engine light came on.
Scanned vehicle through GFF and found fault codes P008700 Fuel rail/system pressure -- too low (passive/sporadic) and P304500 Fuel pump electronics faulty (passive/sporadic).
Both faults occurred at approx the same date/time with ambient temp at -19 degrees celcius after initial vehicle start up.
Checked fuel pressure on low side. 5.9 bar obtained after ignition prime and idle of 5.2 - 5.7 bar measured.
Pressure did not bleed off when engine shut off.

Removed rear bench seat and inspected fuel delivery unit connectors.
No corrosion, damage, or water intrusion present.
System is currently operating as normal, suspect temperature related issue.
Cannot be diagnosed further at this time.

Battery: Car needed to be boosted as car drained battery with hazard on waiting for a tow.
Performed battery test, test results stated to charge battery with SOC at 35%.
Battery charged and tested OK

The report then continues to suggest my brother-in-law drive the car and see if the issue comes back (it has). The dealers repair estimate is as follows (abbreviated):

Dealer fix one: Replace low pressure pump (pump, washers, nuts, o-ring, shop supplies, labor): $1779 (Canadian dollars)

If that doesn't work:

Dealer fix two: Replace fuel module (8K0906093E) as possible second fix: $506 (Canadian dollars)

Absent from the estimation was the high pressure fuel pump.

Now that this has proven to be a recurring issue, I'd like to do the repairs myself and save him some money.

My question is, given the above does anyone have any insight as to what the issue actually is? The dealer suspects a low pressure pump or module. I personally wouldn't rule out the high pressure pump. Looking for any feedback/experience/tips etc. If this was my car I might just fire up the parts cannon and do all three and see what happens but for my brother-in-laws sake I thought I'd ask here if anyone has experienced something similar and has a better sense of what the actual fix is.

Thanks suggestions etc!

[Smac770]

P0087 is fuel pressure too low. This is on the high pressure rail, after the HPFP. But how too low was it? Constantly low, just dips out on WOT, etc.

It sounds like the in-tank pump delivery was fine during the tech test, 5-6 bar is spot on.

P3045. Fuel pump control module. But without the complete DTC text, who knows what the subcode (actual issue) was. B8.0, so you have a basic 2-wire DC Bosch pump. The J538 controller has power, ground, the two wires to the pump, and a PWM signal wire from the ECM. The J538 applies 12v to the motor in alignment with the PWM duty cycle. So a simple construct.

If I were going to try anything parts cannon, I'd replace the J538 and see if that fixes it. It sits in that slot under the seat bench next to the in-tank pump top, as I understand it. Follow the big green/yellow and brown wires from the top of the in-tank pump.
https://wolfautoparts.com/catalogsea.../?q=8K0906093E

[DrGER]

...
Now that this has proven to be a recurring issue, I'd like to do the repairs myself and save him some money.
...

It seems to me this is where having access to a VAG-aware diagnostic tool (VCDS, OBDeleven, even a Foxwell NT510 handheld) would prove useful for reading full fault codes and poking at various live data (i.e., measuring blocks).
The "P304500 Fuel pump electronics faulty (passive/sporadic)" DTC is likely a good hint, though; see, e.g.: https://www.audizine.com/forum/showt...l-Pump-problem

A possible source for new: https://www.fcpeuro.com/products/aud...urg-8k0906093e --g

[nagrover]

Thanks for the replies.

I don't have a VAG diagnostic tool. I may be able to source one.. not sure.

Any thoughts or experience that would lead one to believe this is related to the low pressure pump vs high pressure pump?

Could the low pressure pump be failing and therefore starving the high pressure pump... leading to the P0087 code? Or would the low pressure pump typically throw it's own code in that situation?

Thanks again

[DrGER]

...
Could the low pressure pump be failing and therefore starving the high pressure pump... leading to the P0087 code? Or would the low pressure pump typically throw it's own code in that situation?
...

See the post referenced above -- they reported DTCs P3045, P3044, and P0087, which sounds pretty close to your situation. Replacing the J538 controller solved their fuel pump problem. --g

[nagrover]

Thanks @DrGER and @Smac770. I found a module fairly inexpensively. Will arrive here Friday. I'll start with that and report back.

[nagrover]

Update: I replaced the "Fuel Pump Drive Module" as mentioned in this thread.

It's been 3 days and the issue seems to be resolved. Normally the issue would happen within 20 minutes of the engine running so confidence level is high this was the right fix.

Part 8K0906093E

I bought an aftermarket part on RockAuto made by PIERBURG. Comparing with the OE unit that came out, they look physically identical and are both "made in Portugal".

Thanks!

[Smac770]

Pierburg makes more than a few of the original parts on these engines. I would refer to them as an OEM, rather than third-party (OE = Audi stamped; OEM = same thing by same people but without the Audi stamp, so could be produced at a lower quality standard but is functionally the same product; third-party = they made an equivalent but they don't make the ones which Audi uses). That's the normal way of things, buy an OE if you can find it used, or buy the OEM and save the coin. It's rare cases where you only want to buy new OE.