P03A5 and cylinder balance codes

[dingleflopper13]

Hello,

I have a 2011 Q7 andI recently deleted EGR, DPF, adblue, and swirl flaps. It was tuned out to reflect that before the delete because it was immobile prior to to faults.
After the delete while test driving it to take my garbage and recycling to the center it popped up the code above for cylinder 2 pressure too high and every other cylinder aside from 3 is currently saying contribution/balance.
It starts and idles seemingly fine and even drives somewhat normally unless trying to accelerate more than grandma would that causes hesitation and stutters. Drove it back home and shut it back off.
I used an Autel scanner and checked live data. Cylinder 2 is the only one even showing pressure data and it does seem to get high. Fuel pressure according to Autel seems to match actual versus requested pressure.
Could it still be the HPFP even with the pressures matching? Or is there something else it could be?
No other tuning aside from delete file has been done so no extra boost or any thing like fueling or timing.

 

[Cr2013]

Did you ever figure this out? I’m running into the same issue with my tune straight out of the gate as well and the tuner thinks it’s an issue with the car and not the tune. I only had a def pump code before and now I’ve got 5 injectors consistently throwing balance codes and cylinder 2 showing an over pressure code

 

[Jarrvis]

Hey - bumping this as I recently got the exact same issue. Got the "no restart in 350kms" AdBlue fault. Took the car to Audi and they couldn't diagnose or reset the code. Took to local performance shop and they performed the EGR and AdBlue delete only (not DPF) and tuned to Stage 1 (Malone / TuneZilla).

Got the P03A5 Cylinder 2 pressure too high code.
Cleared that.
20 mins later got P0272 Fuel Injector #4 Contribution/Balance code fault. Then car went through each cylinder with the same Contribution/Balance code fault (P0263 for Cyl #1, P0269 for #3, etc.). No more Cylinder 2 pressure too high code.

Recalibrated all injectors, issues all came back one by one.

Vehicle runs totally fine, no hesitation, no misfires throughout.

Curious if either poster ever got this figured out.

 

[Cr2013]

Did you have a Malone dealer load the tune on or was it one of the self use loaders?

 

[oilhammer]

The CNRB only has one pressure sensing glow plug, and I believe it is on #2 cylinder (it's the center cylinder, passenger side).

 

[Jarrvis]

Hey a Malone dealer loaded the tune. We've been in frequent contact with Malone and they provided a modified tune, but no solution. They are now spitballing, saying to replace the injectors, check all wiring, swap glow plugs, etc.

That's correct, only one sensing glow plug on #2. No more pressure related codes (P03A5) since the first couple times. All now just contribution/balance related. (Update: Technician told me that Cylinder #5 also has a sensing glow plug on the 3.0 TDI)

Hey CR2013, do you happen to know what your pressure readings are? Mine is around 45-48 bar at idle on Cylinder #2 but was at about 53 bar when I was getting the P03A5 codes. 48 bar is in line with a friend's same year TDI who doesn't have any error codes, so seems about right.

 

[Cr2013]

My injector balance numbers were aroind 3-4 mg/stroke differences. The code print out I have from when I had the codes is showing injector 2 being at 21.8 bar which tossed the code. I can check the pressures when my wife gets home and let you know what they are now and see what my balances are as well.

 

[Cr2013]

I would also check your cam phase adaption for chain stretch. 5-6 degrees is about the limit before you need to replace that. My car is the cata so pressures may be a little different, I’m not sure how much of the engine perimeters changed between the two motors

 

[Jarrvis]

Ok cool.

Interesting as my injector balances were around -1.5 to +1.5mg/stroke with Cylinder #6 being 3.5mg/stroke when I was getting the P03A5 code.
But since that code cleared, deviations are -0.3 to +0.3, super stable.

I'm only at 130k kms (80k miles) but will check for that chain stretch too.

Did you ever solve your issue? What was the cause of the contribution/balance issues cycling through each cylinder on yours?

 

[Cr2013]

To be honest, we have no clue other than just a potential bad tune. I had a Stevenson tune which was causing all the codes. I got ahold of the local Malone dealer after putting the stock tune back on and I never had any issues at all with the Malone tune. I would maybe suggest going back to the the foundation of the stock tune and having Malone build a new tune from that. That’s all we did and I haven’t had an issue since. I have no experience with how tunes get made but that seems like the right path to take there.

 

[Jarrvis]

Thanks for that insight. In the middle of it all we flashed back to stock tune with AdBlue + EGR Delete tune but still ran into the contribution/balance faults so went back to Stage 1. But it hasn't crossed anyone's mind that possibly the Delete tune is the issue.

 

[Jarrvis]

The shop had the car today to troubleshoot further and are citing a faulty NOx sensor #2 issue (readings are frozen at 65000ppm when spec is about 150ppm). They suspect that the AdBlue + EGR Delete without the DPF delete still gets feedback from the NOx sensors and these readings are causing the contribution balances to get out of sync. They are recommending I do a DPF delete (about $2000 CAD as they have to weld in straight pipes) and this will cause the system to fully ignore the NOx sensors. But, no guarantee to solve the problem.

You would think the EGR + AdBlue delete tune would also ignore the NOx sensors...but I guess they're still required for the DPF.

I'm gonna try cleaning my NOx Sensor #2 first to see if that solves the issue.

(also, checked my cam phase adaption and it's OK at -2.35 degrees)

 

[oilhammer]

The NOx sensor value "frozen" is by design, part of the tune. Those sensors are indeed ignored, just there for the SCR (which is why non-SCR TDIs that still use a DPF do not have NOx sensors).

 

[Jarrvis]

Dang...thanks for that. I reached out to Malone / TuneZilla for their input and they confirmed that the NOx is ignored.

 

[Jarrvis]

Spitballing here, but what if the values prior to the delete are stored somewhere in the tune? Like, is the 65000ppm from sensor #2 stored or "hardcoded" into the tune? I'm thinking that what if other components and sensors require an NOx reading, I would imagine a reference value is stored somewhere to "trick" the dependent components into thinking the deleted sensor is still there. And if so, I would guess it's the last logged reading.

Curious to know if you know @oilhammer .

 

[oilhammer]

I do not know specifically. I just know that some software changes completely remove certain PIDs, and some plug in some value to that slot and the ECU's mapping is forced to go off of whatever that value is.

 

[Jarrvis]

ok thanks, appreciate how responsive you are. I'll float this thought with Malone and report back.

 

[Jarrvis]

TuneZilla's Answer:

"The adblue delete you have already ignores NOx readings and has no influence on contribution faults.
The only thing we can do is making the fault detection less sensitive but it will only heal sympthoms but won't cure the disease.
There are no other sensor that require NOx reading. In this car all NOx related procedures happen in ECU. "

So, I'm kinda back to the drawing board. My predicament is I can't remove the tune and see what happens because my car is in the "No Restart" state due to the AdBlue issues which required the delete.

Hoping the OP posts their solution...

 

[Jarrvis]

Hey just to close the loop on this issue, I have finally gotten it resolved. The issue was due to a bad custom partial delete tune from Malone/TuneZilla. The solution was to peform a full DPF delete and install a full canned/base/stock delete tune.

I ended up switching shops and the new shop spent many hours troubleshooting mechanical issues and jumping through hoops to appease TuneZilla. They ruled out all mechanical issues. The shop ultimately did the following to confirm it to be the tune:
- Flashed my vehicle back to stock
- As I was at "0 kms no restart" with my AdBlue issue, the car would not start after flashing back to stock. So, the shop was able to perform an AdBlue countdown reset to get an additional 80 kms of countdown and drove the vehicle for about 50kms, no fault codes appeared.
- They then loaded a canned delete tune (AdBlue + EGR + DPF) and drove the vehicle for about another 50kms, no fault codes appeared and my contribution/balance values were getting back to normal. (Although not a good idea without physically eliminating the DPF filter, loading the full delete tune was not an issue for a short period of time.)

Once confirmed to be the tune, the shop then did the expensive work: removed my DPF and all emissions related stuff. They waited overnight to do a cold start and no engine codes returned. TuneZilla made good and reimbursed me the cost of the tune.

In hindsight, the initial shop was on the right track with removing the DPF, but their reasons (NOx sensor) didn't make sense...was too risky for me to take that chance and we probably never would have known the root cause to be the tune. The critical error with the initial shop was when they flashed me back to the "stock" AdBlue + EGR delete tune and the issue persisted, it was actually still a custom tune, not a stock tune. Had they flashed me to a stock or canned or base tune, this likely would have identified the problem.

Recommendation for anyone reading this: If you are getting random contribution/balance or cylinder pressure codes (or any codes for that matter) after having received a tune, the first thing you need to eliminate is if you got a bad tune. If your tune provider tries to blame your car, don't accept that at first. If you got a "custom" tune, ask to have a stock tune loaded. If you got a partial delete, ask to have a full delete loaded temporarily to troubleshoot. If you are getting a delete tune and a performance tune all at once, I recommend doing it in phases. Do the delete tune first and if all is good then load the performance tune. Also, don't get any other work done at the same time. I did (fuel filter change, intake cleaned) and it set us off in the wrong direction at first when troubleshooting.

All told, this cost me 7 weeks of time and about $1000 more than it should have. If I knew then what I know now...so I'm hoping that even if one person out there reads this and it saves them a big headache, that's a small win.

 

[indyscott]

I don't know what a "delete tune" is. Can you explain that?

 

[Jarrvis]

Hey @indyscott it's a tune that deletes the emissions components - AdBlue, EGR (Exhaust Gas Recirculation), and DPF (Diesel Particulate Filter). When you get a full delete tune (including DPF removal), you also need some mechanical work done to physically remove the DPF.

With that tune, you never have to worry about AdBlue, EGR, or DPF related error codes or problems again, the components and all sensors are deactivated. There is no performance enhancement, but a possible small improvement in fuel economy.