Fault code P0299 Boost - 2019 Crafter

[MB999]

Mmi - some one has suggested fuel pressure sensor/ regulator issue to me, what parameters should I click to present a data log for this?
Could do with looking at fuel
Pressure and injectors I guess….

Allthough I have no codes to suggest a problem here, just still the underboost po299….

Been out again today, still doing it but less frequent since the oil flush/change.

 

[mmi]

The only thing I can think is that the new clean oil running through the turbo allowed it to run faster, creating more boost?
So would this be an indication that it is a turbo related issue after all ?

I'm not sure if the oil would make any difference - it's properties e.g. lubricity does not change much within normal change cycle.
Anyways, if you have made a log after oil change would be interesting to have a look.

Mmi - some one has suggested fuel pressure sensor/ regulator issue to me, what parameters should I click to present a data log for this?
Could do with looking at fuel
Pressure and injectors I guess….

Below a few new (bolded) ones to start with - kept quite a few old parameters so we could see if there is any correlation between old and new ones.

​

IDE00021 Engine RPM​

IDE00075 Vehicle speed​

IDE00190 Charge air pressure: specified value​

IDE00347 Air mass: actual value:​

IDE00407 Rail pressure regulation: status​

IDE00589 Fuel pressure​

IDE01378 Fuel high pressure: control deviation​

IDE07376 Intake manifold pressure: act. value calculated​

IDE07744 Particle filter: air pressure sensor 1 bank 1: raw value​

IDE07784 Turbine actuator 1 bank 1: posit.feedback - Specified value​

IDE07785 Turbine actuator 1 bank 1: posit.feedback - Actual value​

IDE07822 Fuel pressure regulator valve: activation​

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the middle of the turbo where I saw a whisp of smoke come from a few times?

It’s much better than it was but I still get eye stinging exhaust stink from back of the engine.

Are these still present?

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Attached also a preset file for the measurement setup above (again: remove the .TXT file extension - leave .u01 for VCDS)

 

[MB999]

The exhaust stink and eye watering sting seems to have gone, still a bit stinky but not like it was so perhaps normal….

Maybe f you think the oil change has had no effect, the only thing going on is the wynnes turbo came cleaner it running through with the v power fuel.
I’ve ran 3/4 of a tank through now so maybe that’s had an effect after all ?

 

[MB999]

just done the log you suggested. i clicked the turbo button ( to get a more detailed log, is that right?)

started the van, it seemed to crank a few times before it fired. the first part i am reversing of the drive and out the street. i then drove a good few minutes up the hill and onto expressway, soon after it faulted po299 and quickly after we pressed marker (1). i contuned on then at the next set of lights i cycled the ign to clear the fault again (marker 2). then drove on, soon after it faulted agian (marker 3 pressed quickly after)...... i reset it a further time and then eventually at home i let it sit and tick over for a half minute.

hope this info helps ? (and hope I've done the file correctly)

 

[mmi]

just done the log you suggested

Hmmm.... the file contains only two samples - instead of continuos data stream. Perhaps you forgot to click "Log/Start" to actually start the logging?
Anyways, the fuel pressure specified and actual were practically the same in the file. However, then boost pressure specified and actual had quite a deviation still.

i clicked the turbo button ( to get a more detailed log, is that right?)

It helps just a bit. Much better data rate is achieved by selecting "UDS Group requests - by 7 (or 8)"

 

[MB999]

Oh sorry mate , I did select uds by 7’s, and then pressed turbo…. I clicked start log, the end, then save….
It’s confusing how it does it as I swear it asks me to save at the start, and at the end too in a different way…. I’ll suss it out …. Eventually

So we know from the po299 that it’s an underboost, and now the data supports that with the shown deviation from specified amount, how in the heck do we pin point that to a cause?
With no evident vac leak that I can find, surely it has to be in some way the electronic control of boost or other wise a waste gate issue , surely….

It’s booked in the garage a week tomorrow, I was really hoping to have found the cause before then

 

[mmi]

how in the heck do we pin point that to a cause?

I also did whitness a tiny amount of smoke come from the turbo , it was from the centre of it where the two halves meet and the actuator rod sits. A tiny puff when revved.

The exhaust stink and eye watering sting seems to have gone, still a bit stinky but not like it was so perhaps normal….

The above bother me - revving at standstill doesn't create much pressure.

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Another view - from the log of 18th July
Picture on top - the pressures. Picture below turbo actuator positions (specified/actual)


So it seems that also actuator specified and actual coincide quite well. However, would expect to see actuator regulating turbo more intensively. If I'm interpreting this correctly the turbo actuator tries to create boost almost full time (as sticking at 100%).

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See below similar plots from mine - two approx. 20 second periods at full throttle.



So, not sticking at 100%, and obviously eases off not to overboost.

Also bypass valve seems to come along eventually (below).

IDE07792-ENG180363 Turboc.1 turbin.bypass valve 1 B. 1: pos.feedback - Specified value​

IDE07793 Turboc.1 turbin.bypass valve 1 B. 1: pos.feedback - Actual value​

 

[MB999]

So do you think the turbo actuator is the suspect , or is it the vaccum which controls it?

 

[mmi]

So do you think the turbo actuator is the suspect , or is it the vaccum which controls it?

No. Based on the data it seems the actuator is doing what it's supposed to do - tries to do max boost (set at 100% - both specified and actual position) but for some reason the turbo itself don't produce enough boost (or there is a leak) so actuator could ease off from 100%.

As both specified and actual values of the actuator conincide I would think no problem on that side (vacuum & actuator movement).

 

[PhillH]

Hi there, have you checked for play in the turbo? Had the same issue on a caddy and the turbo had play. Changed the turbo and problem solved. Worth a try checking it if you have not done so already.

 

[PhillH]

Hi there, have you checked for play in the turbo? Had the same issue on a caddy and the turbo had play. Changed the turbo and problem solved. Worth a try checking it if you have not done so already.

Also tally’s up with the oil change as the new oil would be thicker so can not pass the seals as easy.

 

[MB999]

I had thought this… but there is no play in the turbo both hot and cold side, impellers seem ok, no play nothing obvious…..
seems to operate well in most load conditions and just throw a wobbler at this one quite specific condition….
I did think maybe the fresh oil was allowing the shaft to be better lubricated and spin up quicker but that’s a bit of a leap really as I’m clutching at straws now.
It’s booked in NWvagtech monday, I’ll see what they come up with.

I think it’s fine but then when it dumps its boost out the actuator it does quite stop its dump quick enough. What I can’t tell is if that is a turbo waste gate issue, or the vacuum that controls it, it finally the electrical side of all of that via ecu/sensors etc…

 

[MB999]

Goin out in it shortly with a vac guage from turbo actuator strapped to windscreen wiper to watch what it does

 

[MB999]

Ok… so tonight I teed my vac gauge into the tube between the n75 outlet and the turbo actuator.
It pulled a good vac on start up.
I drive and the gauge went up and down as you would expect.
Then it dumped the vac completely, and stayed dumped. Zero vac.

I pulled over, kept engine running, pulled the vac hose that h goes to the inlet of the n75, it still had a solid full vac.

So….
It’s not a turbo issue, it’s not a vac pump issue,
It’s a boost pressure solenoid issue or, what ever electronically controls the boost pressure solenoid., a sensor ….

What I need to work out now is….
When the n75 gets its signla
Voltage to energise and dump the vac, why is it staying open.

I had replaced the n75 valve , granted not with a gen Vw one, but with a metzler one supplied by gsf car parts (as opposed to fake pierburg junk off eBay).

Either the new n75 is dead or what ever feed the voltage to it is at fault.

What is that? The map sensor ? (I had replaced that as well with a bosch one).
What else tells the n75 to energise? Is it the ecu? Or another sensor? Or a combination of sensors?

I feel like im close now, im happy. Think it rules out the turbo and the vac pump.

Mmi, what do I check from here please?

 

[PhillH]

Ok… so tonight I teed my vac gauge into the tube between the n75 outlet and the turbo actuator.
It pulled a good vac on start up.
I drive and the gauge went up and down as you would expect.
Then it dumped the vac completely, and stayed dumped. Zero vac.

I pulled over, kept engine running, pulled the vac hose that h goes to the inlet of the n75, it still had a solid full vac.

So….
It’s not a turbo issue, it’s not a vac pump issue,

What I need to work out now is….
When the n75 gets its signla
Voltage to energise and dump the vac, why is it staying open.

I had replaced the n75 valve , granted not with a gen Vw one, but with a metzler one supplied by gsf car parts (as opposed to fake pierburg junk off eBay).

Either the new n75 is dead or what ever feed the voltage to it is at fault.

What is that? The map sensor ? (I had replaced that as well with a bosch one).
What else tells the n75 to energise? Is it the ecu? Or another sensor? Or a combination of sensors?

I feel like im close now, im happy. Think it rules out the turbo and the vac pump.

Mmi, what do I check from here please?

Try a n75 from another VAG car / Van, they are all the same. I would not fully trust a non genuine sensor.

Have the pipes been mixed up on the N75 when looking at the issues?

Can the N75 be bypassed for further confirmation?

 

[MB999]

I could bypass the n75 by putting the inlet vac tube straight to the turbo actuator tube.
That would deffo change the problem to an over boost rather than the underboost I have as the vacuum on the inlet is now proved good and constant so it wouldn’t allow the turbo to actuate the waste gate when boost is it’s top level….
(I dont want to damage anything by doing that).

It’s probably unlikely that the inlet and outlet tubes are mixed up because a) the inlet tube retains good vacuum even when fault occurs, it’s the outlet tube that looses its vac and stays at zero.
AND the tubes are actually different bore sizes. (Large and small) so you don’t get them mixed up.

It IS possible the new metzler n75 is new but supplied defuncts.
But I think it’s as likely that what ever controls the n75 valve is at fault, be it a sensor , wiring, or ecu.

What is clear is when the n75 receives its signal to cut the vacc, the solenoid is then staying open and the vac dumping out the little bell like thingy ….so the vac is not resumed at the actuator and in turn the waste gate stays open. Which is where my boost is being lost.

The n75 valve isn’t re-opening after flashing shut to kill the vaccum that holds the waste gate shut.


Just need to work out why?

Exhaust gas temp sensor ?
Charge air inlet and outlet temp sensor?
Map sensor ?
Maf sensor ?

It’s gotta be one of these , surely?

 

[mmi]

Exhaust gas temp sensor ?
Charge air inlet and outlet temp sensor?
Map sensor ?
Maf sensor ?

Mass air flow sensor was already recorded - nothing unusual there. See below purple line - it's very well aligned with the rest (the shape of the curve).
Also the charge pressure sensor has been recorded.
Can't imagine how the others would influence the issue. Also non-working sensors would likely generate fault codes.
Anyways, in VCDS they would be

IDE04003 Charge air temperature sensor​

IDE04090 Exhaust temperature bank 1​

What is clear is when the n75 receives its signal to cut the vacc, the solenoid is then staying open and the vac dumping out the little bell like thingy ….so the vac is not resumed at the actuator and in turn the waste gate stays open. Which is where my boost is being lost.

Hmmm... it seems that mono-turbo engines do not report waste gate position at all. Couldn't find such a position sensor.
The measurements would be in:

IDE07790 Bypass valve for turboch 1 turbine inlet: activation​

IDE07792-ENG180363 Turboc.1 turbin.bypass valve 1 B. 1: pos.feedback - Specified value​

IDE07793 Turboc.1 turbin.bypass valve 1 B. 1: pos.feedback - Actual value​

But I'm afraid they don't actually do show on DAUA engine - except full time zero.

 

[MB999]

i still think it’s possible the waste gate is getting stuck open.
The boost pressure vents off via open waste gate, map sensor then says ok the pressure at inlet manifold has now reduced so closed n75 and restore the vac to pull actuator into closed waste gate position……. And I turn restore boost pressure…
The ecu then says hang on, actuator is in closed position because I’ve just closed n75 and it should be pulling the actuator diaphragm into closed position ,the ecu May even read the actual in the closed position but the map sensor says pressure is still too low , because it’s secretly venting off via a stuck open waste gate , the ecu says hang on this isn’t right th re pressure shouldn’t be low when the n 75 it giving vacuum to the actuator , it should be closed ? I’m not happy with this so I’ll fail safe and cut the vac to n75 so waste gate opens to protect from over boost…. (It’s already open, that’s the issue)

This is possible….. I guess….. the fail safe in ecu energising the n75 and cutting the vac to open waste gate and protect against wonky readings…..

Strange I have no other fault codes so the above does explain why I have no sensor related codes, I’m simply loosing boost, not through vac or exhaust leaks, but through a waste gate that isn’t shutting properly…. All sensors are actually reading right but the information they’re presenting to the ecu doesn’t add up, so it fails safe.
It reports an underboost code, which is right, because it can’t report on waste gate function becuse thats just spring controlled and doesn’t actually get any electronic feedback ti report a fault.

This is a plausible explaination (in my simple head )

 

[MB999]

Update:
Today the van has been into vagtec NW for diagnostic …,

He says the van has been mapped because it’s certainly is very pokey, the turbo is likely worn and struggling to produce the boost the map is looking for, recommends new turbo.

I’ll get one ordered…. Is there any one place better at recon turbos or are they all much the same?
London turbos , atom turbos ? Any recommendations?

 

[PhillH]

Great news that you are getting to the bottom of your problem. Try AC turbos in Skelmersdale, they may have an exchange unit for you.