Here we go again... P201500 error code

[kolqa]

Hello! I know this is a common problem. I have Audi A4 b8.5 2.0T (CPMB) with metal intake (flex fuel). When I first encountered this issue I decide to replace second part of intake (where flaps is actually located https://audi.7zap.com/en/usa/audi+a4.../1/133-133022/ this part below fuel rail (2) ) together with angle sensor everything were ordered brand new.

1665337932416406.jpg

After installing I hit the same error code again unfortunately.

IMG_0276.jpg

On my car I have following modifications:
- forge diverter valve (I think it can be the problem)
- hybrid turbo (custom IHI which usually came with stock car)
- downpipe
- intake

I think it can be a diverter valve by forge causing this problem. It was connected using following diagram:

IMG_4436.PNG

I asked local service to check my vacuum leakage and they said everything is fine but something tell me that's it's not true... maybe it's a solenoid but how to check it any ideas? Also I have an interesting data logging for flaps.

Idle:
IMG_0277.jpg
Pushing:
IMG_0278.jpg
IMG_0285.jpg

I need to admit that this problem appears only when I go slightly uphill and push the gas to the floor or goes in a manual and downshift to 4.5-6k RPM and if I drive normally then I don't see this error by "normally" I mean transmission in "Drive" and just average daily ride without pushing the gasket (without high RPM). Any ideas where to look next after new intake and angle sensor were installed? I don't feel any strange work and everything works fine but this check engine light is annoying . thanks in advance!

[Smac770]

Maybe toss a T on there and run a vacuum gauge taped to the dash, see if the vacuum levels from the system are dropping out at some point.

The actuator is actuated by vacuum being passed to it from the vacuum pump. Not enough vacuum, it won't swing the arm the full intended range. I presume this is what you see while logging load flap angle actual vs specified. Sometimes it doesn't make it to 99% when it should. Is it just slow to get to 99%, or does it not make it to 99% at all? You'll have to ignore transitional situations where you're blipping up and down around 3k. The logic is simple, 3k+, 99%, 3k-, 0%.

Drop out during a shift. So when the DV is activated?

The stock config on a B8.5 has only two objects on the vacuum pump output. The brake booster and the intake manifold actuator. That's it.

[kolqa]

Is it just slow to get to 99%, or does it not make it to 99% at all?

Thanks for reply! It does 99% all the time but sometimes it's like actual(99.100%) requested(99.999%) and after some times it's rise up to 99.999%. I'm worried about idle where is actual 5% but should be 0%... I think if I can find what's is going on with idle it will be much easier to debug issue after 3k rpm.

Maybe toss a T on there and run a vacuum gauge taped to the dash, see if the vacuum levels from the system are dropping out at some point.

You mean put T on the vacuum line which is goes from solenoid to intake (my diagram in the first post of this thread)?

[Smac770]

5% actual at release is normal. It'll never be 0% actual.

P2015 is actual vs specified differ by >25% after 1.5 seconds when flaps are commanded on (100%); ie actual is less than 75%. So 99.1 vs 99.9 is not going to set the DTC. Even 90.1 vs 99.9 wouldn't set the DTC. 5 vs 0 wouldn't either, but that DTC doesn't monitor when the flaps are commanded off (0%) anyway. That would be P2004.

https://www.forgemotorsport.com/Reci...duct--815.html

This thing? It doesn't connect to the vacuum pump output. You're using a boost tap on the PCV hose to provide a connection to the intake manifold vacuum, something that is not used for any engine management purpose in a stock EA888 config. The IM vacuum is completely separate from the vacuum pump vacuum, which is what drives the brake booster and the intake manifold flap actuator (via the same kind of cutoff solenoid as the DV uses).

So the DV could not be relevant if it's hosed correctly; it's not even on the same vacuum system.

[kolqa]

5% actual at release is normal. It'll never be 0% actual.
https://www.forgemotorsport.com/Reci...duct--815.html

This thing? It doesn't connect to the vacuum pump output. You're using a boost tap on the PCV hose to provide a connection to the intake manifold vacuum, something that is not used for any engine management purpose in a stock EA888 config. The IM vacuum is completely separate from the vacuum pump vacuum, which is what drives the brake booster and the intake manifold flap actuator (via the same kind of cutoff solenoid as the DV uses).

So the DV could not be relevant if it's hosed correctly; it's not even on the same vacuum system.

To be more specific this one:
https://www.ecstuning.com/b-forge-pa...mfsitvrbl~frg/

I checked one more time how its connected since I'm didn't do it myself. The guy who connected everything didn't use boost tap instead he connected it with a T in the vacuum line. He said that plastic boost tap which was in kit not compatible with my metal intake that's why he did it like this.


This is how it's connected to my IM vacuum:

diagram2 .png

This is "green" line which I marked on diagram from above, it's goes along the engine to the vacuum lines with T shape
IMG_4440-edited.jpg

Here it's connected to T and the yellow line goes to the IM some kind of the same solenoid from forge
IMG_4441-edited.jpg

Here is yellow line goes to solenoid
IMG_4442-edited.jpg

Does it make any sense to buy a boost tap for metal IM:
https://www.ecstuning.com/b-ecs-part...013625ecs01~a/ or this https://www.ecstuning.com/b-cobbtuni...ap/8v1300~cob/ and connect Forge output line from solenoid to boost tap which will be located here
IMG_4443.jpg
instead like it connected right now?

Also, today I did a couple of runs to trigger this error and recorded a video from the screen of the phone.
The first test was done on the straight road just push the acceleration pedal to the floor, the second was done in manual mode just shifting between 2nd and 3rd gear to make it >3k and <3k rpm. You can see how at some point it just drops down from 99 to lower numbers.



My check engine light was not triggered but OBD eleven after those runs shows that Engine has one fault and ofc its P2015:
IMG_0293.jpg

So, with your help I found that near IM there is an additional solenoid probably it's at number four (4) at this schematic https://audi.7zap.com/en/usa/audi+a4.../1/133-133022/ and maybe in my case, it's faulty.

[Grouch]

So, with your help I found that near IM there is an additional solenoid probably it's at number four (4) at this schematic https://audi.7zap.com/en/usa/audi+a4.../1/133-133022/ and maybe in my case, it's faulty.

I'm in the same situation as you. I have a P2015 code that no can seem to figure out. My shop said that's the only logical thing that could be faulty. Swapped it out and did nothing.

If you figure it out, please let me know.

[Smac770]

The gas only 2.0T uses the plastic intake manifold. The flex fuel 2.0T uses the metal intake manifold.

The FMFSITV is designed to tap the intake manifold vacuum/pressure for actuating the valve (vs electromagnetic actuation in the factory valve). It uses the same electrically controlled valve that Audi uses for other vacuum/pressure actuated devices (intake manifold flaps, and on the B8.0, heat exchanger coolant shutoff). But those other devices run off the vacuum from the vacuum pump, not the intake manifold.

The difference is the vacuum pump circuit is always vacuum. The intake manifold is vacuum at off throttle but boost on throttle. It's this pressure build up of going off throttle that the DV addresses; the throttle plate is no longer opening as much, the impeller is still spinning down, generating pressurization, the DV opens to bleed that overpressure back to the turbo inlet, otherwise the pressure wall will become a barrier to turbo spinning. I presume Forge understands this.

Which makes the vacuum routing harder to decipher. If we consider this solenoid valve to operate like all the other identical Pierburg solenoid air pressure valves on the engine, the upright port is always open. When the solenoid is not energized, the upright port is connected to the horizontal port under the electrical plug. When the solenoid is energized, the upright port is connected to the horizontal port on the same end as it.

When the DV would normally be activated, the IM should be at vacuum since it's at throttle release. The solenoid is energized and the path to the top of the DV is connected to the IM vacuum.
When the DV would normally be not activated, the IM could be at vacuum or boost. But it doesn't matter as the solenoid is not energized, and the two paths to the DV are connected together. Whatever that accomplishes. I don't find any information on how the DV is internally constructed.

So to implement the Forge DV in line directly with how it's intended, you need a tap on the IM. But there's a reason no one has a tap for the metal intake manifold.

That said, I don't really know why it would create a complication with just using the vacuum system. Unless the DV is somehow bleeding boost pressure into the vacuum connection and dropping out the vacuum level in the vacuum system. The DV would kick in at throttle release, but the flaps would not go back to 0 until under 3k. What you'd be looking for in high speed logging is for the load flap actual to drop out while load flap specified is still high and rpm is still over 3k.

Really, just swap back in the stock DV and see if the issue goes away. If it does, you know your problem source. If it doesn't, you've got something else going on. You can just leave the solenoid and it's T connection in place for the time being; as mentioned, the solenoid isn't connecting the vacuum side line to any port unless it's energized. And the factory plug will be back on the factory DV for the test duration.

[kolqa]

I'm in the same situation as you. I have a P2015 code that no can seem to figure out. My shop said that's the only logical thing that could be faulty. Swapped it out and did nothing.

If you figure it out, please let me know.

God damn, that's sucks ... in my case, I have at least a couple of options to check but I'm afraid to stuck in the same loop as you without answers... I will post all my results here buddy.

Really, just swap back in the stock DV and see if the issue goes away. If it does, you know your problem source. If it doesn't, you've got something else going on. You can just leave the solenoid and its T connection in place for the time being; as mentioned, the solenoid isn't connecting the vacuum side line to any port unless it's energized. And the factory plug will be back on the factory DV for the test duration.

Thanks a lot, appreciate all your efforts to help me. I ordered a new factory DV + two solenoids + boost tap. First, I will check everything with factory DV and hope it can be switched easily without my software modification (I'm at st3), if that doesn't help I will try to replace solenoids one by one (near IM and Forge) at the end I will try boost tap to IM and hope I can find the root cause

[kolqa]

Huh, unfortunately, due to high load on the work I don’t have much time to work with the car. I did only replacement of the solenoid valve behind the IM and potentiometer behind oil filter + a breather (line which is on the top of the engine with filter, which connected to IM solenoid). It doesn’t help but give me some results to think about…
1. On idle flaps specified and actual same 0% (before actual on idle was up to 4%)
2. During high speed test there is no random drop from 99% like it was before

Now, I figure out how to trigger P2015 and can reproduce it quite easily:

2nd gear, push gas pedal , when 3k+ RPM actual and specified 99%, now at 4.5-5k just quick release the gas pedal and you will hear the noice from the DV “stu tu tu tu tu” and after this sound your actual value goes to 0% for about 2 secs and then it returns back to 99% until RPM isn’t dropped under 3k

@Smac770 I think it’s shouldn’t drop to 0 even if you release a gas pedal, right? When your RPM 3K+ it’s always should be 99% no matter what?

I didn’t try OEM DV yet, but found such behavior which I described above!

[Smac770]

It's been a while since I played with it. I'll run a log during the breakfast run and confirm the throttle release behavior.

I suspect the activation of the DV solenoid is creating a pathway that is dumping the vacuum through some path out of the DV. Whether or not it should do this, I have no idea. But if you put a vacuum gauge on the line, I bet you see the vacuum level caving out while the DV is being activated (which is on throttle release).

[kolqa]

I’m finally solve the issue with p2015. The root cause for it was in how Forge solenoid was connected to my vacuum line. I wrote to Forge and they confirmed that in my case I need to use boost tap (please see photo below) since it can affect IM solenoid. I want to THANKS YOU @Smac770 you are the MAN! With your advices and notes I tracked the main reason. @Grouch if you have a breather line with white filter (connected on top of the engine) you can try to replace it with new one (06H133583B) during my research I found that some people got p2015 because of that or if you have Forge DV you can check your connection. Thanks to the Forge company for quick replies and trying to help! Customers support means a lot!

The last problem which I need to solve it’s a turbo flutter on the throttle release. I’m sure that it’s related to Forge DV and I need to try softer spring if I understand it correctly but it’s a different story. If I can’t fix it I already ordered TurboSmart DV and will try with it.

[Smac770]

Sorry, I totally forgot about this and never ran the log. Glad they were able to confirm our suspicions. "and on to the next issue",

[JLAllroad]

Why replace the reliable (non diaphragm) OE electronic DV with a vacuum actuated aftermarket model?


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[Grouch]

No aftermarket DV on my car. The part # you supplied says it's up to the 2013 year.

Smac770, would that still cause an issue for 2014 and above?

[Smac770]

The OP had an aftermarket DV that used an electrically managed solenoid to control passing vacuum to actuate the DV. (versus the purely electro-magnetic solenoid in the factory DV). He had connected it such that the vacuum source was the vacuum pump (which "powers" the brake booster and the manifold flaps actuator, and for B8.0, the coolant shutoff valve) rather than the intake manifold. This was incorrect, and corrected by connecting the DV vacuum source to the IM.

Grouch, if you do not have the exact same scenario, then your P2015 is a completely different situation. It could well be that your issue is instability on the vacuum line, but your root cause would clearly have to be something different.

You're going to have to start with an analysis of logging the load flaps actual vs load flaps specified vs rpm (as the transition should happen right at 3k all the time). Is the actual not close enough to 0 when under 3k, not close enough to 100 when over 3k, or is it slow to transition when the rpms transition across 3k?

I posted somewhere at some time what vacuum I measured when removing the vacuum line from the N316 solenoid (the solenoid that controls the vacuum passing to the load flaps actuator ). You might pull that and put a vacuum gauge on it and drive around and see if the vacuum level remains stable. Then put the line back on the N316 and put the gauge on the line going to the actuator. See if the vacuum is showing as expected as controlled by the N316.

Could also be a problem with the load flap angle sensor. Or the load flaps or actuator themselves. When you manually move the actuator arm, do you see the value go to 100 (99) and 0 (near 0) as you actuate and release the arm?

Ie, no idea what's been done, what's been learned, I'd say you're at ground zero and start from there building what's actually happening, when actually does the actual vs. specified discrepancy happen and to what degree, etc. Then you can speculate cause.

[kolqa]

Why replace the reliable (non diaphragm) OE electronic DV with a vacuum actuated aftermarket model?

@JLAllroad Without the aftermarket DV life would be boring, I spent many weekends trying to figure out the problem by changing various parts, it was fun and educational. . Fine, all jokes aside. You can check this really old thread. The Ultimate Diverter Valve Information Thread In the middle of the thread you can find a small description about new revision OEM DV in my case after I switch to stage 3 with hybrid turbo I experienced the same problem: (and I think metal is better than plastic in the hot engine areas)

it is actually designed to leak pressure. In my own experience, using this revision DV provided slower response, slightly lower peak boost, and less reliable operation. Peak boost always varied from run to run, and performance was better and worse on different runs for no apparent reason

I want to add I faced such a problem with a new revision OEM DV and since at that time all my friends rode with Forge DV without any issues I decided to get the same but due to an incorrect connection, I faced with p2015 problem. I have no idea if it needs to be changed on a stock car but when you go with tuning the best solution would be aftermarket DV and after some experiments, TurboSmart looks like the best option if you don't want to deal with vacuum lines and all this additional stuff like boost tap just plug-n-play. The Forge also provides a high-quality product you just need to be more careful with connection and just pick correct spring according to your boost and also service after some time.

just want to add all this DV dilemma depends on your personal situation, car configuration, hardware etc ... in my case, OEM was not so good, for someone this may be best to just leave OEM DV.

[JLAllroad]

@JLAllroad Without the aftermarket DV life would be boring, I spent many weekends trying to figure out the problem by changing various parts, it was fun and educational. . Fine, all jokes aside. You can check this really old thread. The Ultimate Diverter Valve Information Thread In the middle of the thread you can find a small description about new revision OEM DV in my case after I switch to stage 3 with hybrid turbo I experienced the same problem: (and I think metal is better than plastic in the hot engine areas)



I want to add I faced such a problem with a new revision OEM DV and since at that time all my friends rode with Forge DV without any issues I decided to get the same but due to an incorrect connection, I faced with p2015 problem. I have no idea if it needs to be changed on a stock car but when you go with tuning the best solution would be aftermarket DV and after some experiments, TurboSmart looks like the best option if you don't want to deal with vacuum lines and all this additional stuff like boost tap just plug-n-play. The Forge also provides a high-quality product you just need to be more careful with connection and just pick correct spring according to your boost and also service after some time.

just want to add all this DV dilemma depends on your personal situation, car configuration, hardware etc ... in my case, OEM was not so good, for someone this may be best to just leave OEM DV.

I remember that B7 thread from about a decade ago (and how many revisions). I see many glorious reviews of those that replaced their torn diaphragm DVs with GFBs with huge accolades that replacing a broken OE piece with an aftermarket piece makes a huge difference. Most of these comments are subjective with nothing to measure by. In regards to the GFB there’s also a thread out there where many are having issues with it leaking and or seizing.

Note, there’s a common misconception when it comes to the “weak” spring in the OE DV, it’s not there to hold boost, it’s there to dampen the movement of the piston. Given the OE piston is vented there is no pressure pushing against it. A number of tuners have tested it to 30psi without issue, very few are running more than that.


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