OwenP

I have a 2014 A4 B8 with a P2293.
EDIT: From what I have read it appears to be the Fuel Pressure Sensor. Would anyone know if it could be the HIGH Pressure or LOW Pressure Sensor?

My car has no driving issues. Starts, Idles and runs fine. If anything, it may idle a "bit" off
Any direction on where to start would be appreciated.

Thank You

SMac770

Would really prefer a full VCDS autoscan log. What's the rest of the text from whatever tool you're using?
But offhand, with nothing but a P2293 code, that says there's a problem with the high pressure rail, pressure actual is not matching pressure specified.
There is no pressure sensor for the low pressure system if the engine is a CAEx motor (for you, that means if you have a manual).
Problems could be the high pressure fuel pump (HPFP) is failing, the cam or tappet driving the HPFP is failing, the high pressure sensor is not working correctly, or there's a problem with the supply from the low pressure system (low pressure pump or controller problem maybe).

You'll probably want to do logs of fuel pump:specified value (this is the duty cycle of the low pressure pump, iirc, mine is 35% to 55% idle to WOT), fuel pressure (this is measurement of the high pressure rail sensor, ~4000kPa idle, 15000kPa WOT), high fuel pressure: specified value (not sure why the actual is in kPA and the specified in MPa, but you're looking for these values to be roughly the same; your P2293 is saying hey these are not close enough). There's three other "high pressure" values, they might be worth logging just to see what they say.

If the DTC refers to N276, that's in the HPFP itself. G247 is the high pressure rail pressure sensor. Now, a complexity if you have a B8.5 and automatic, you'll have the CMPx/CPMx (whichever is actually the right spelling) flex fuel motor, which does have a G410 low pressure rail pressure sensor. I don't have a flex fuel motor so I don't know how that data might advertise itself in the advanced measuring values. You'll just have to sort that; I have no idea what normal values would be from the G410.

OwenP

Thanks for the (very detailed) response!
The car is a B8, Automatic, no-flex fuel
I actually had it scanned at Autozone, so there really isnt much more info to provided. I suppose I should take it somewhere reputable for a more concise scan.
The only additional info it provided (which is pretty much what you said) was "P2293 Fuel Pressure Regulator 2 Performance. Indicates that with the engine cranking or running the PCM detected the difference between commanded fuel rail pressure and actual fuel rail pressure was greater than the maximum allowable value" Solution: Replace Fuel Pressure Regulator.

incidentally, I also have a code for P0299 - Turbo charger Underboost, but I'm quite sure they are unrelated.

SMac770

Well, generic OBD scan tools will return generic OBD codes. You'd need an Audi aware/specific capable scan tool to get the Audi codes text probably. Here's one example from a VCDS scan:

008851 - Fuel Pressure Regulator Valve (N276)
P2293 - 002 - Mechanical Malfunction - Intermittent

Now, it could be that P2293 and 008851 are synonymous, but I don't like to assume that there might not be other variations of Audi DTCs that match to the generic P2293 code.

It would be curious for you to have a US B8.5 automatic and not have the flex fuel capable engine. When you open the hood and remove the engine cover, is the intake manifold metal or plastic? Metal means you would have the cold start injector and the G410 low pressure rail fuel pressure sensor. But I'm certain this code is about the high pressure rail.

I just happen to have P0299 and plan to replace the HPFP to see if it might clear it up. My P0299 comes from cruise conditions, not wide open throttle conditions. Think of P0299 as the boost version of P2293, where boost has been more than 2psi below requested for at least 6 seconds. Replacement of the HPFP has solved weirder things, and mine has over 190k miles on it.

But yeah, just like P0299 simply means "something somewhere between where the air goes into the car and comes out the tail pipe is not working", P2293 just means "something caused the high rail fuel pressure to be less than intended". It could be a shortage of fuel supplied to the HPFP (tank pump failing or clogged, or the controller fritzing out), it could be the pumping of the HPFP (the intake camshaft cam and the follower tappet and the spring pump on the HPFP), it could be an errant sensor, it could be the fuel injectors are leaking like mad, it could be the HPFP has developed a leak of fuel into the cam area, it could be you've got a leak in the high pressure rail or at the unions of the line connecting the pump and rail. Lots of possibilities, more code detail is likely to not help much, but it could be the DTC detail points to something completely not typical.

Lots of logging and looking for what seems like normal data and what seems like out of bound data is the better place to start. The other being parts roulette, starting with the high pressure rail sensor/sender and the HPFP.

OwenP

Well, I always wanted a VCDS scanner so maybe this is the time to get one!
Thanks again for the very thorough response.
When I remove the plastic shroud/cover the manifold is metal. I attached some pics as well.
Interesting that you have a P0299 and are thinking of changing out the HPFP. Since I'm getting a P0299 and P2293 perhaps it's the same (related) issue. I'm curious to see if your P2099 clears after you replace the HPFP.
I hate to be just a parts swapper, or parts roulette as you said, but I may try and change out the High Pressure Sensor and see where that goes.


Shroud removed

Low Pressure?

High Pressure?

OwenP

Did you change your HPFP? Any luck?

SMac770

Sorry, been away. The HPFP is a planned project. Right now, I'm too busy putting miles on the car. :-) Probably something I'll try to get to this month.

OwenP

No problem at all. Glad to see you're still racking up the miles.
Did you happen to see my previous post with the pictures? The "Orange" Sensor is the High Pressure Sensor, Correct????
Thanks again

SMac770

So if I look at ETKA diagram for the B8.5 CPMA/CPMB motor (the flex fuel capable one, with the metal intake manifold) for the high pressure fuel system, we see the general location of the sensor on the fuel rail. https://nemigaparts.com/cat_spares/e...q/736u/133240/
If we take that part number (for part 13) and throw it into parts.audiusa.com, we get a picture of an orange sensor: https://parts.audiusa.com/p/Audi__/4...6J906051D.html
(in your pic, the two little lines of text, the upper one looks like it starts the part number, but I can't read it; the lower row starts HPS, probably high pressure sensor, or such).

OwenP

So, I replaced the High Pressure Sensor (Orange) on the fuel rail. I also removed the HPFP to check it visually and to check the Cam Follower. Both looked good so I reinstalled.
Unfortunately the P2293 is still present. As well as the P0299 and now a 3rd code!...P053F. I'm sure these are not related to the P2293, but frustrating nontheless.
I suppose the next step is to replace the HPFP. Would you agree?
Or, actually, I should get a more concise scan to pinpoint the issue.