P00AF - 'stuck' with new turbo

[rajjinator]

Hi all,

I have just fitted a new turbo from London Turbos and am getting a fault relating to the actuator position. It's actually in a Crafter, but it's a DAUA engine so relevant in all areas I guess so posting here for better visibility.

To cut a long story short, the turbo has been replaced and i'm now getting "P00AF 00 [00100000] - Stuck". VCDS reports this fault immediately after clearing the codes and even before starting the van. This suggests to me that the actuator rod adjustment has been set incorrectly i.e. preloaded so that the position sensor is reading out of range when no vac applied?

I have checked the vacuum into the N75 and this is OK. I have also used a vacuum pump to check the movement of the actuator, and it does move, but maybe only 10mm or so. I'm not sure how much it should move? VCDS live data shows it move from 63% up to 100%, and then releasing vacuum it drops back to 63%.

Looking for advice before I remove it and send it back to London Turbos as they have suggested i simply "send it back for inspection", which is not ideal...

Here's what VCDS outputs after clearing the codes and simply turning on the ignition... (Note the "Turbine actuator 1 bank 1: posit.feedback - Actual value" of 63.07 % with the engine off, when it expected value is zero. I imagine this is how the ECU is able to set a code before even starting the engine.


1 Fault Found:
16408 - Actuator Module for Turbocharger 1
P00AF 00 [00100000] - Stuck
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 205437 km
Date: 2024.09.20
Time: 21:11:03

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 57 °C
Intake air temperature: 11 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.484 V
Unlearning counter according OBD: 40
Turbine actuator 1 bank 1: posit.feedback - Specified value: 0.00 %
Turbine actuator 1 bank 1: posit.feedback - Actual value: 63.07 %
Turbine actuator 1 bank 1: posit.feedback - Offset closed: -11.81 %
Turbine actuator 1 bank 1: posit.feedback - Raw voltage: 2.541 V
Accelerator pedal travel: raw value: 0.00 %

Readiness: N/A

 

[Dellmassive]

Was the turbo referred?

Same turbo refitted?

I think there is a turbo calibration in vcds.. and something about a high oil pressure bed in, setting in the engine ECU?

That maybe reset the turbo calibration settings?

 

[rajjinator]

I purchased the turbo from them before sending mine back (exchange), but it was based on the OEM numbers on the original turbo. It looks to be identical but I see your point.

I read the service manual before doing the work and yes it says you should enable the raised oil pressure setting in VCDS which I did. This just runs at full oil pressure for 1000 miles as I understand it to ensure that new components get proper oil supply during run in.

There's also a turbo adaptation procedure which I have tried to run, but it aborts due to "safety reasons" which I believe is due to the actuator position sensor being too far out of range.

 

[Dellmassive]

Gotcha......

Might need to speak to someone who's actually fitted a new one or done the job.

.

 

[mmi]

Please post

(1) - engine's blockmap data - engine not running (ignition on)​

(2) - engine's blockmap data - engine ticking over (idling 830 RPM)​

VCDS > Applications > Controller Channel Map >​

Tick/fill boxes as above and click Go.

VCDS flashes screens for a moment (when finished hit "Done, Go Back") and there should be files blockmap-01-... in folder C:\Ross-Tech\VCDS\Logs\....

PS. For the above either VCDS HEX-V2 or HEX-NET cable is needed.

 

[Dav-Tec]

From doing these before for some local garages after they've fitted turbos sounds like the actuator rod isn't set right there's a minimum feedback value it's should see think it's 0.5v when closed and then the adaptation can be done from there. If it's outside of tolerance it won't start the adaptation

 

[rajjinator]

Hi, appreciate the assistance! filename ending 2111 is the not running blockmap, the other is the idling blockmap.

 

[rajjinator]

From doing these before for some local garages after they've fitted turbos sounds like the actuator rod isn't set right there's a minimum feedback value it's should see think it's 0.5v when closed and then the adaptation can be done from there. If it's outside of tolerance it won't start the adaptation

Rod doesn't seem to be adjustable, it's fixed. there are some slotted holes on the actuator bracket. I tried moving it which just moves the issue to the other end of the range. i.e. instead of being stuck at ~60% when commanding 0, it'd sit around 20% but then when it commands 100% it would only reach 70% actual. Not sure at this point if the reconditioned turbo doesn't have enough travel on the VNT rod, or if the actuator isn't the right one or isn't working properly...

 

[Dellmassive]

Rod doesn't seem to be adjustable, it's fixed. there are some slotted holes on the actuator bracket. I tried moving it which just moves the issue to the other end of the range. i.e. instead of being stuck at ~60% when commanding 0, it'd sit around 20% but then when it commands 100% it would only reach 70% actual. Not sure at this point if the reconditioned turbo doesn't have enough travel on the VNT rod, or if the actuator isn't the right one or isn't working properly...

have you got some pics to add into the mix?

so we can see what we are talking about?

 

[rajjinator]

have you got some pics to add into the mix?

so we can see what we are talking about?

The VW service manual guides i've seen (although they don't seem to cover this specific engine) talk about adjusting a threaded rod and seperate lock nut. This seems to be fixed in one position (no lock nut) and some slotted holes on the bracket instead, which has the same effect as adjusting the rod length as far as i can tell, but to no avail.

Not a great photo but it's the best I can do with it still in the van. you can just about make out the slotted holes on the black actuator bracket, and the rod whilst i'd imagine is threaded, doesn't look like it is meant to be adjusted, i.e. factory set with no lock nut present?

 

[Dellmassive]

google search for the DAUA turbo

..

 

[Dellmassive]

looks like this guy done the same job.

.

 

[mmi]

Indeed, well out of adjustment - the sensor voltage engine stopped should be about 3.7 Volt and idling at 0.75 Volt.
The same also seen in a test here -

[T6_measured] 01-Engine - Built-in tests for turbocharger

HOW-TO run engine's built-in test for turbocharger Engine running VCDS > Select > Engine > Basic Settings > IDE00457 - Test of turbocharger Select "Measuring Values" Pick up e.g. the following data items for monitoring: IDE00021 Engine RPM IDE07375 Charge pressure before throttle valve...

www.t6forum.com

the rod whilst i'd imagine is threaded, doesn't look like it is meant to be adjusted, i.e. factory set with no lock nut present?

I think the thread below is very useful - the same for DAUA engine. The actuator needs to be removed for adjustment.

Help please Flashing coil light and EML on. Multiple codes 31391 27202 8208 8216 8217 8338

I see they give you a few circlips as I’d imagine this will be the part that provokes the most swearing!

www.t6forum.com

 

[Dellmassive]

thats a PITA,

the guide shows to offer up the NEW & OLD actuators together to get the initial setting.

i suppose the new and old rod settings are different.

 

[mmi]

Good news is that there is a correction table in post 67- compared with data from blockmap - my guess would be -3.5 end piece turns left
Surely would better to apply 700 mbar vacuum and measure/adjust the IDE07783 for 0.75V.

 

[Dellmassive]

so, where is this rod length adjuster bit . . .





in this pics of the actuator?

 

[rajjinator]

Great info guys. Here's what I'm thinking though. As there are no visible threads on my actuator rod and the holes on the actuator bracket are slotted, I was able to adjust the resting position of the actuator using these holes yesterday. I could get it to read close to 3.7v engine off/no vacuum, but then it would only reach as far as 1.8v or so at idle with vacuum. So I'm wondering if the actual VNT mechanism itself doesn't have enough physical travel. I'll have another look later today. Nightmare!

 

[rajjinator]

so, where is this rod length adjuster bit . . .

View attachment 262577



in this pics of the actuator?

View attachment 262578

This is what my actuator rod is like. No lock nut or visible threads.

 

[rajjinator]

Removed the actuator and it is now clear that the VNT mechanism is not moving properly/jammed. This explains why the position sensor is so far out of range at rest. The fault code was dead on the money with "stuck".

Annoying, but I'm removing the new turbo and returning it to London Turbos for "inspection". Will report back when I hear from them.... FML

 

[rajjinator]

The plot thickens... They contacted me today to say they found oil and what appeared to be adblue in the VNT mechanism which caused it to jam up. Quite how adblue gets upstream of the adblue injector and back into the VNT mechanism is beyond me.

Unless (i've not owned the van very long) the previous owner had accidentally put adblue into the fuel tank? Now i'm super paranoid about refitting the new turbo before working out if that has indeed happened or not. Would it be obvious from taking a fuel sample? I'd have thought the fuel injectors and HP pump would be knackered if that was the case, which appear to be fine - general running is OK, and injector correction values in VCDS don't seem too far out of whack to me.