CJAA P00AF Adventure

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
Hello all,

I have a 2013 JSW TDI, with the CJAA engine and DQ250 trans. The car sits just shy of 170,000 miles

Last week I finally tuned the car with Malone Stage 2 (DSG as well) and since then I have been getting a P00AF error code

Upon original inspection, the vacuum line was chewed right by the actuator! I cut the damaged bit off so the line is good again.


After this, the light went away for a while, then came back roughly 300 miles later

I will note, the code only occurs when the engine is hot.

Tonight I did some more investigating

https://streamable.com/jlofj1


Video A

https://streamable.com/8956a6
Video B

https://streamable.com/8gf55l
Video C

in Video A, the car has the N75 valve unplugged which is simulating the valve NOT working. keep the exhaust sound and lack of turbo whine in mind.
once the valve is plugged back in, it starts to come back, the turbo whine starts to return but it "bogs" while doing so

in Video B, the car would NOT hold near requested boost and is bogging JUST like it was doing in video A with the valve unplugged, all the increase's in boost/rpm is from me trying to see if the valve will start acting normal again

in Video C, the car is acting normal. i turned the car off after Video B, then turned it back on, and everything was normal. shortly after stopping Video C the bogging returned.

i will also note, i have only found this happening when the engine is HOT. never when cold. i suspect the valve has failed in such a way where it fails when hot (engine at temp)

it is also weird, that ANY amount of throttle "fixes" the problem and the car will not report a fault. this is seen in Video B as I am keeping the turbo boost above requested even though it dips below when idling. the opposite is seen in video A briefly, no CEL while valve unplugged. after valve is plugged in, car begins to "bog" as it trys to get boost up to pressure. you can hear the turbo speed going up then down shortly after the 23 second mark in video A. after this "bogging" a CEL appears on the dash

I have tested the plug wires, one is VBAT, the other is PWM as intended. I then tested my OHM resistance on the N75 unit itself, came back at 17.8/17.9
From my breif searching this is out of spec

A new valve has been ordered from FCP and I will pick it up tomorrow. I will also measure that valves resistance and report back

Due to the mileage on the car, and the symptoms listed above I believe the problem lies in the N75 valve, not in the turbo actuator/vanes.
I would love to hear your thoughts on this!

My N75 valve PN, for the next soul to try and find the correct ohm spec of it
1K0906627A
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
Is this only started happening after the tune. You could record the results in vcds and send them to Malone, your tune might need to be adjusted. I know on mine and full throttle I get two minor boost spikes every time. I've gotten used to it.
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
Is this only started happening after the tune. You could record the results in vcds and send them to Malone, your tune might need to be adjusted. I know on mine and full throttle I get two minor boost spikes every time. I've gotten used to it.
If the new valve has the same ohm resistance ill reflash my stage 0.5 (ran like 50k miles no problem on it) and see if the issue comes back

I will also do some logging

I dont think its the tune though, it might be but it was driving okay for a bit before it started acting up
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
If the new valve has the same ohm resistance ill reflash my stage 0.5 (ran like 50k miles no problem on it) and see if the issue comes back

I will also do some logging

I dont think its the tune though, it might be but it was driving okay for a bit before it started acting up
It's very possibly issue was there you just didn't notice it because it wasn't running higher boost. It still could be something to talk to Malone about they might have some pointers on where to go or what to look at.
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
Just got the new valve, it is 35 ohms of resistance
Again, the PN is 1K0906627A and my current one was measuring at 17.8-17.9 ohms (for the next person trying to find this info as i couldnt get a direct answer)

I will install, then watch the graphs to see what changes
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
Did the n75 correct the problem?
It did for like 1,000 miles but it has come back

The car runs fine even with the code present, I think there is a slight leak in the vacuum diaphram of the actuator

Because of that, I've decided to leave it be until I replace the turbo (eventually)
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
<1 month before I am scheduled to install the turbo, i find the problem.

The high pressure EGR tube was leaking at the EGR valve causing this pressure issue.

Installed a new gasket and removed the block off plate sandwiched between the tube and the valve, 250 miles / 10 heat cycles CEL has not returned....
 

Mrrogers1

Veteran Member
Joined
Jun 25, 2006
Location
Omaha NEEEBRASKA
TDI
2011 Golf TDI 6MT, 2011 Jetta TDI DSG, 2015 Golf Sportwagen S TDI DSG
Not hard at all, time from grabbing wrench to turning the key was like 15-20min max
So I'm trying to wrap my head around IF this (the gasket) issue could also happen on car with full EGR delete. :unsure: EGR function is usually coded out in the tunes so I don't know why the leaky gasket would tell any systems there was an issue OR why it would cause the turbo to react differently under the conditions presented.

I have a guy that is getting the code and I need to try the trouble shooting steps and maybe have tune checked but came across your post (thank you for all the details) and thought I'd ask.
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
So I'm trying to wrap my head around IF this (the gasket) issue could also happen on car with full EGR delete. :unsure: EGR function is usually coded out in the tunes so I don't know why the leaky gasket would tell any systems there was an issue OR why it would cause the turbo to react differently under the conditions presented.

I have a guy that is getting the code and I need to try the trouble shooting steps and maybe have tune checked but came across your post (thank you for all the details) and thought I'd ask.
because my problem was on the side of the EGR which is mechanically bound, not software bound.

the EGR valve was coded out, but that doesn't stop the gasses from the high pressure EGR tube from trying to pass into the valve. the leaky seal between my EGR valve / block off plate / high pressure tube was leaky and appearently caused enough of an energetic loss to give a P00AF DTC
 

Mrrogers1

Veteran Member
Joined
Jun 25, 2006
Location
Omaha NEEEBRASKA
TDI
2011 Golf TDI 6MT, 2011 Jetta TDI DSG, 2015 Golf Sportwagen S TDI DSG
because my problem was on the side of the EGR which is mechanically bound, not software bound.

the EGR valve was coded out, but that doesn't stop the gasses from the high pressure EGR tube from trying to pass into the valve. the leaky seal between my EGR valve / block off plate / high pressure tube was leaky and appearently caused enough of an energetic loss to give a P00AF DTC
AH HA! Ok, gotcha. Well I'm thinking the issue my buddy has are not leaky gasket because EGR is (may have) gone away. ;);) I'm going to use what you provided around trouble shooting though and will also do some logging of the requested vs actual boost pressure (as you did) to see if maybe the tune needs a little tweaking OR if it's the N75 valve.

Thanks again for the info.
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
AH HA! Ok, gotcha. Well I'm thinking the issue my buddy has are not leaky gasket because EGR is (may have) gone away. ;);) I'm going to use what you provided around trouble shooting though and will also do some logging of the requested vs actual boost pressure (as you did) to see if maybe the tune needs a little tweaking OR if it's the N75 valve.

Thanks again for the info.
sounds good, i ended up finally deleting the rest of the EGR junk out of my car when i was doing the big turbo swap. just make sure your N75 ohm reading is correct/good, then make sure you have no vacuum leaks, then make sure there are no high pressure exhaust leaks (evident by soot build up around the leaky area)

if all of that checks out, apply a vacuum to the turbo actuator and see if it losses pressure over time. at this point you should have found something causing the problem, if not the VNT vains are sticky and a new turbo is probably in order
 

Arawak420

Member
Joined
Feb 9, 2021
Location
SoCal
TDI
JSW 2.0
I still have the soft code p00af with no cel. The other day by battery barely wanted to crank and the cel came on for the same code. New battery and its back to soft code no cel.Car has been running fine but doesn't have the boost im use to. The dealer replaced the turbo and actuator via diselgate but the soft code still appeared 500miles later and I passed the extended warranty. I'm guessing they didn't check the n75 and just opted to replace turbo and actuator. I did an ohm test just now and its reading 16.0 ohm. I see a slight melted crack in the bottom n75 hose. I'll change em both. Will keep updated. 🤙🏽
 

Arawak420

Member
Joined
Feb 9, 2021
Location
SoCal
TDI
JSW 2.0
Got the new n75 valve and its reading the same ohms at 16.0-17.0. I got the exact part number you listed. I thought this valve was suppose to be between 25.0-35.0ohms. 🤔
 

zpotter08

New member
Joined
Oct 25, 2023
Location
Hamilton
TDI
2.0 2014 wagon
Love to hear any update. After changing alternator and removing charge pipe along with bottom boost pipes and rad my car is reading p00AF but no dash lights. Hoping I can follow along your check list lol.
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Eastern CT
TDI
2013 CJAA GTB2266
Love to hear any update. After changing alternator and removing charge pipe along with bottom boost pipes and rad my car is reading p00AF but no dash lights. Hoping I can follow along your check list lol.
could have a boost leak somewhere, or maybe you managed to knick a vacuum line (though there arent any where you would be doing an alternator)

my p00af was really because my EGR high pressure tube gasket / block off plate had failed.
 

Cody.tdi

New member
Joined
Nov 2, 2020
Location
Erie PA
TDI
11 JSW
Will post this here in addition to a separate thread of it's own to see if anyone can help.

For reference I have a stock 2011 JSW with roughly 163k on the dash. Bought it with roughly 155k on it and have not done any modes to it until recently.

Here's how the P00AF code came to be. I purchased the Kerma TDI performance intake, turbo inlet hose, and turbo discharge dampener. Once these arrived I promptly installed everything eager to have some more turbo noises and more power. Got everything installed just fine. Went for a test drive and during a 3rd gear pull it threw into limp mode. Went back to scan codes and P00AF came up indicating the turbo actuator was stuck open. mind you there was no issue whatsoever prior to installing these parts.

Fast forward to days later, frustrated, I came back to diagnose more and try to find the issue. Ended up vacuum testing all lines which were holding solid except for the VNT actuator which was holding vacuum however leaked down roughly 5" of vacuum over about 5 minutes of time.

Went back to the drawing board with no other ideas or solutions to try aside from installing the stock parts back on the car. Before doing so I ended up logging a 3rd gear pull before removing the aftermarket parts as well as afterwards which are attached below. You will notice the wild boost pattern with the performance parts on. Also I have attached the vcds codes which were pulled with the aftermarket parts on. *Can not figure how to upload csv files/log files to the post

Any help here would be super appreciated. The only thing I can conclude is that the aftermarket parts are accentuating an issue that is already present being the leaky vnt actuator or tuning related however I wouldn't have thought just those intake parts would affect things that drastically.

Trying to get a better idea of what's going on before throwing money and time at it to replace the vnt actuator etc. Thanks in advance.
 
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