NOT FIXED: Help on S3 error - Fuel Pressure Regulator Valve (N276)

[jnrdavo]

yeah, no worries and thanks for the offer.

I've ordered a new one online, so let's see if that fixes the issue. Quite cheap, so no issue if it's not the issue.

[guile]

i just ran a quick google mate and i would definitely be following this diagnosis process as the next step...

ffa13ce7-4bf3-4fb8-b809-d73a5c76a641_FPR+_Testing+and+Inspection,+Componen t+Tests+and+General+Diagnostics_+Diagnostic+Proced ures,+Fuel+Pressure+Regulator+Valve,+Checking.pdf (justanswer.com)

[jnrdavo]

Fixed!!! And as I expected, it was simply the fuse..

I'd been working off online fuse charts and they don't match mine 100% (for some strange reason).

Fuse box Audi A3 8P (fusesdiagram.com)

I ended up buying a new multimeter (another excuse as mine was 20 years old!) and the Fluke accessories, which came with some nicer 'probes' that were handy. I just plug one end in to the unplugged 'connector' at top of the fuel pump and the other end I just started to probe in the engine fuse box... it got a signal on F7, which had no fuse..

Obviously I'd remove that one when I was trying to fault find the horn problem (and dropped it in to the engine ether!).. then plugged a spare on in to the wrong slot, based on the pic from the link attached.

Anyway, all done now, and I have a new fuel pump (higher rated!) and new adapter coming that will be spare

I'd love to actually get a proper map of what the fuses are in my car, but everything seems to be working fine (except the boot light), so I might try the same logic on that one to see if I can work out why it is not working as well.

Thanks all for all your help, it was great to reach out to the community again and get support when you need it, and all for free

[mike]

Fixed!!! And as I expected, it was simply the fuse..

I'd been working off online fuse charts and they don't match mine 100% (for some strange reason).

Fuse box Audi A3 8P (fusesdiagram.com)

I ended up buying a new multimeter (another excuse as mine was 20 years old!) and the Fluke accessories, which came with some nicer 'probes' that were handy. I just plug one end in to the unplugged 'connector' at top of the fuel pump and the other end I just started to probe in the engine fuse box... it got a signal on F7, which had no fuse..

Obviously I'd remove that one when I was trying to fault find the horn problem (and dropped it in to the engine ether!).. then plugged a spare on in to the wrong slot, based on the pic from the link attached.

Anyway, all done now, and I have a new fuel pump (higher rated!) and new adapter coming that will be spare

I'd love to actually get a proper map of what the fuses are in my car, but everything seems to be working fine (except the boot light), so I might try the same logic on that one to see if I can work out why it is not working as well.

Thanks all for all your help, it was great to reach out to the community again and get support when you need it, and all for free

Great to hear you got it sorted. easy fix in the end but takes a lot to get there.

Maybe have a look at the online versions of Elsawin & see if the circuit diagrams
are better to read.


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[jnrdavo]

Yeah, that would have been a quicker solution. Either way, I've learnt more about electrical resistance and car maintenance again, which was the whole purpose of getting this car. I didn't have to pay anybody to fault find/fix, and that's worth something on my book.

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[jnrdavo]

Ok, so still not fixed.

Replaced so far:

1. HPFP
2. Fuel Pump Relay (R4)
3. Fuel pump filter

I know there are better ways to do this than replace parts, but I was fine with an upgraded HPFP, and also the relay... Filter was original, so it probably needed replacing at some point, so that was fine.

So now I'm getting these two errors. I did disconnect the battery and clean the negative terminal, is there anything that needs to be done after changing out the fuel filter?

I also loaded the VCDS advanced measuring values..

Fuel Pressure Regulator 9.27 bar
Electric Fuel Pump 1/2 Load 5.9%
Fuel Pump Shutoff Time 54.00 secs
Fuel Rail Pressure (actual) 9.19 bar
Rail Pressure (specified) 50.00 bar
Rail Pressure (actual) 9.27 bar

Interesting to see the specified and actual is far off and doesn't change when I start the car and give a light throttle.... Is the obvious thing it's not getting enough fuel??



3 Faults Found:



008852 - Fuel Pressure Regulator Valve (N276)

P2294 - 004 - Open Circuit - Intermittent

Freeze Frame:

Fault Status: 00100100

Fault Priority: 2

Fault Frequency: 1

Reset counter: 255

Mileage: 221493 km

Time Indication: 0

Date: 2021.12.22

Time: 15:57:10





005634 - Power Supply Terminal 30

P1602 - 002 - Voltage too Low - Intermittent

Freeze Frame:

Fault Status: 00100010

Fault Priority: 2

Fault Frequency: 1

Reset counter: 255

Mileage: 0 km




000135 - Fuel Rail/System Pressure

P0087 - 002 - Too Low

Freeze Frame:

Fault Status: 01100010

Fault Priority: 2

Fault Frequency: 1

Reset counter: 255

Mileage: 221494 km

Time Indication: 0

Date: 2021.12.23

Time: 00:06:28



Freeze Frame:

RPM: 1178 /min

Load: 41.9 %

Speed: 0.0 km/h

Temperature: 25.0°C

Temperature: 23.0°C

Absolute Pres.: 990.0 mbar

Voltage: 14.224 V

[Alister]

Given that you've already replaced some parts, and that the fault code on the Fuel Pressure Regulator Valve (N276) says it has an open circuit, assuming it's not the Fuel Pressure Regulator Valve (ie you've been able to confirm continuity in the circuit) I'd be having a very close look at the electrical connectors (inc pins) and tracing back the wiring as far as possible to make sure it hasn't been pinched / shorting out somewhere.

[jnrdavo]

Yeah, just need a break to be able to spend the time.

You wouldn't believe that the S5 had the p0087 error twice driving today. I went to the fish markets and to check out a S3 on Parramatta road, no issues (and no issues for years now).
Got game, parked up for 20 mins, then off for a drive again. EPC light came on, yue car stopped shortly after.
Had the vagcom with me, reset it and it came on again about 2 mins later. Reset again and drove 5 mins home...

Very strange that same error in two cars ! Maybe bad fuel from local station is causing the S5 error?

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[jnrdavo]

The saga is still ongoing... I can start the car, if I press the accelerator... I've gone to basic settings in vcds, I can see that requested fuel pressure is 50 bar, but actual is 5 bar..

First pic is with engine off, power on:



Second pic is car started, idle (but very rough):



Does anybody know what Quantity Valve opening Angle is? It looks like that may be off (negative number??)

High Pressure System Adaptation is also -2 bar ??


I did a bit more digging, and you can see below that I used a keyword here..



First pic is the Low Pressure fuel pump under the back seat. Take a look at this dust!!

I then had to clean it up, this is what that looked like. You can now see from the first pic how much dust there actually was (look at the depth of the dish!!)



I disconnected all the electrical connections, cleaned them, then re-connected, but still no luck.

Latest error in VCDS I'm getting is:

1 Fault Found:

008852 - Fuel Pressure Regulator Valve (N276)
P2294 - 004 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00100100
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 221507 km
Time Indication: 0
Date: 2022.01.10
Time: 01:08:19


Any suggestions? Could it be the LPFP not delivering enough fuel to the HPFP?...

[ManuTT]

Sometime, high pressure fuel pump errors are coming from a low fuel pressure from the other pump in the back..
anyway, the best help in these cases are to generate a real time graph with vcds while driving so to check what is failing and when..then create an excel file with these data (also with vcds)