Hi I seek a little wisdom.  Our 2010 Yeti 1.2 tsi is showing the engine warning light and was sluggish (Limp mode I presume but quite driveable) - when I look for codes (OBDeleven) ....

 

Initially I got P334B00 - Charge Pressure Actuator Mechanical Malfunction 

 

I cleared the fault and no problem for a short while - then fault came back the same.. Cleared the fault again and now I have a different code...

 P155A00 - Charge press. ctrl. - Charge pressure not reached

 

I see that I can get a new actuator for not crazy money and looks easy enough to replace on the car but I am not certain it is the culprit and I think I saw some people suggesting it is not worth replacing without also replacing the Turbo - the car has over 123,000 miles on the clock but drives OK and even with this fault it just gets a bit sluggish.  Car owes us nothing so an easy cheap fix is worth a try if it has a resonable chance of sorting the problem for now.

 

1:   Am I completley confused and on the wrong track?

2:   I wonder if it is a waste of time trying to replace just the actuator - or worse it might cause new problems?

3:   I think I would need to recalibrate after changing the part - can I do that with my OBDeleven?

 

I did see talk of a shim being added retrospectivly to some of these actuators - we do not appear to have that shim - but given the age/mileage and the fact the car has been fine until now I am pretty sure the lack of shim is not the problem.

 

And if I do go ahead and try a new actuator - do I care where it comes from / who made it or do I just get the cheapest I can find 🙂

 

Thanks for any thoughts

 

Greg

 

Hi Greg,

Was the issue fixed?

I'm having the same issue as you.

Regards

Juan

Hi Juan

In the end I did buy a new Actuator from Turbo Surgery in Peterborough - I sent them a photo of the rod length and they said it would fit - which it did. The new one was a "Melett" and looked pertty much the same as the old - it has been working very well ever since. I had quite a fiddle getting off the tin shrouds that cover the connection of the actuator arm as one of the fastenings was very tricky to access but I somehow managed in the end. Once the tin cover was off it turned out the 'E' clip holding the arm to the flap lever was missing and it is possible that this was part of the reason behind the actuator misbehaving (though I took the old unit apart and it did seem to have a broken plastic part inside - which might have been casued by the pin sticking).

I also found there was a shim on the mounting face as mentioned in some web sites (I had thought not before). The new unit did not have an 'E' clip so I had to buy that (of course the way things are these days I bought a box of them off eBay).

I fitted the new actuator with copper slip on the pivot - based on web reading I should maybe have used some fancy very high temp grease but hopefully OK (so far so good and nearly a year in, though car has only done about 3,500 miles since).

I could not get into an adaption routine in OBDeleven - when I went in via Engine > Subsystems as advised somewhere it said "Unavailable" so maybe (hopefully) not relevant on our car. Many web instructions are to do with adjusting length of arm but on mine it is fixed. I dared start and run the car gently but then worried so spoke to a very helpful guy at M H Vehicle Diagnostics & Tuning who after some discussion thought I should try and drive it and if OK then OK - unlikely to damage anything. If it drives badly then could take it to him. So I dared drive it and it seemed to go very well. Felt much faster and more perky than it has for ages though maybe my imagination.

I had seen on youtube someone suggesting a calibration routine...

1- turn ON the ignition;

2- immediately turn it OFF;

3- wait 5 seconds;

4- repeat previous steps for a total of at least 15 times.

Wonder if this is real - I don't think I did that 15 times but maybe I did, or I did it a few times - it all seems a bit voodo to me!

I decided in the end that the critical thing must be the length of the actuator arm from the mounting face to the pin at the end (I measured to one edge of pin as easier but I suppose does not matter assuming same diameter pin and one measures to the same place on both old and replacement). This arm length is what would be affected by the shim on the mounting face so the use of a shim suggestes it needs to be right to reasonably fine tolerance. I suspect if that length is identical to the old one it will likely work without any calibration but I suppose it might also be an issure of how functionally close the new unit is to the old as the arm length is only setting it for the at rest position.

Given my missing 'E' clip it might make sense to remove the shroud before buying a new unit and check yours has the clip and the pin is not stiff or seized where it attaches to the waste gate. If an issue, then freeing and/or fitting a clip might be all you need to do. Otherwise you can remove actuator and meaasure it carefully before starting the search for a match (I looked at loads online and phoned several companies before I found the one I needed).

Good luck :-)

Greg

I meant to attach this as well ....

Greg,

What a fantastic answer!

In my case, I bought my 2010 Yeti 1.2 TSI (like yours) from a small dealer that didn't know what to do with it as the poor car was neglected for too long.

I was constantly getting the EPC light on with P334B error (Charge air pressure actuator-mechanical malfunction). I could see though that the actuator looked brand new so I understood that they tried to solve this issue, but failed.

I've tried the following:

1- "turn on, turn off" 15 times, but the EPC light kept coming. FAIL

2- Install the shim between the actuator and the turbo, did the "turn on, turn off" 15 times, but after 25 miles, I got the engine light with the error codes P155A, U1113 and P334B. FAIL

3- I've bought the VCDS cable and tried to run the 'Initial Adaptation of Charge-Air Pressure Actuator', without the shim, but I kept getting an 'Aborted Safety Reasons'. FAIL

4- I've installed the shim once more and successfully ran the 'Initial Adaptation of Charge-Air Pressure Actuator' with VCDS; no lights on dashboard or error codes after 30 miles, but I need to drive it a lot more before I can say that the issue is fixed.

It's my first time driving a 1.2 TSI and I find it a little bit under powered... maybe it's just because I'm comparing it with the other cars I have.

I'll see how the car handles. Fingers crossed the issue is gone for good.

Thanks a lot for taking the time to reply to my question!

Juan

@joaofpo you may have some wear at the linkage where the actuator rod attaches.

I'm investigating the effect of this on our Roomster at present.

@Breezy_Pete Thanks a lot for this. I'll definitely check the linkage.

Hi Juan - glad you making progress and I hope it behaves well.

Your post makes a couple of interesting points..

It makes me think that your VCDS allows the adaption routine and my OBDeleven does not.

Maybe I got away without that because I was able to replace the actuator with a pretty much identical one so nothing needed to be recalibrated. I did spend quite a bit of time searching for as near an identical actuator as I could and I guess a garage might not be able to devote the time to that.

Also it is interesting that the lack of shim would cause an absolute refusal of the adaption routine, which works apprently OK with the shim.

I think Pete makes a valid point as I noted the actual pivot on the gate seemed pretty worn on our engine but I decided to ignore it. Seems to run OK but I guess if much worse it could influence things - I keep thinking that if that shim makes much difference then wear in the pivot probably could as well. I have always been quite happy with the 1.2 but then my other car in recent years has been a 1987 VW T25 and I have adopted a more gentle style of driving in my old age that suits an old van :-) I do think the Yeti was quite a bit more lively than it had been, once I had the new actuator so there may still be an issue with yours if it really is sluggish (at least when it is just you with not much weight in the car).

Good luck

Greg

Hi Greg,

I got the P155A code again after a few miles, so I decided to take the actuator off and do some measurements.

Mine has a rod 2 cm longer than yours (again, your pictures are a huuuuge help). I also inspected the waste gate linkage after Pete suggestion, but mine looks good, with no gaps. What I did see is that with my current actuator, the waste gate is never proper closed (or opened, not sure as I can't see inside the turbo). I measured the distance between its position with the actuator and the ideal "closed" position and it's exactly 2 cm. I'm confident that the issue is due to the size of the actuator rod. The garage I bought the car from probably installed the current rod, without regarding measurements.

I proceed then to install washers between the actuator and the turbo and I could get as much as 1 cm and I ran another 'Initial Adaptation of Charge-Air Pressure Actuator'. The car felt much more powerful than with just the shim, but after a 50 miles, I got the error back.

I've searched for an actuator and used the same part number as the one in your photos, since I believe our cars are similar. I wasn't sure I was getting the right one, because on ebay, the measurements advertised were always longer than yours, so I decided to buy one as close as yours.

I've received it last Saturday and it's exactly the same size as your actuator. I've installed it, but didn't test it properly yet, because I want to replace the oil separator first, as the car is leaking oil.

I'll keep this thread updated. 😊

Hi Juan

Sorry to hear you still having trouble but it does sound like you are getting creative and I suspect your reports will help others in the future.

Will be good to hear the new actuator fixed it for you so my fingers are crossed :-)

Greg

Hi Greg,

After driving the car more than 150 miles, it seems that the issue is gone. I get no Engine or EPC warning lights on the dashboard and no Error Codes when I plug the car scanner (I mean, there are some codes, but I believe they are related to other issues).

I cannot thank you enough for your messages and photos. I couldn't have fixed it without you.

Also, thank you @Breezy_Pete for your tips related to the linkage.

Juan

Hi, thanks for sharing.

I have the same code P155A so I will also remove actuator and inspect it! :)

Best regards

Anders

On 27/10/2025 at 08:43, joaofpo said:

Hi Greg,

After driving the car more than 150 miles, it seems that the issue is gone. I get no Engine or EPC warning lights on the dashboard and no Error Codes when I plug the car scanner (I mean, there are some codes, but I believe they are related to other issues).

I cannot thank you enough for your messages and photos. I couldn't have fixed it without you.

Also, thank you @Breezy_Pete for your tips related to the linkage.

Juan

Hi Juan

That is great news - I was very pleased when mine worked with the new actuator as I had worried a lot that there must be more to the problem.

I sometimes get depressed with how, despite the potential, the internet is often wasting our time or being used by bad actors to anger and divide us. It gives me hope that it also can be used to share information and make life better :-) I have solved a number of problems with the help of others on the web and I try to share things I discover that I feel might be useful, especially now that cars are so much more complicated and the manufacturers don't want to give us all the information we need to fix them.

Enjoy the open road!

Greg