I've posted on here somewhere about the problems I had with this on my 2016 1.0litre 95hp EA211 3 cylinder. Mine went into limp shortly after starting a journey (about a mile from home) Performance was greatly reduced and the MIL was lit. The car was still in warranty so I just rang the SEAT assist number and they had a man with me pretty quickly. He seemed to know almost before he opened the bonnet what was wrong. A brief check for stored codes and a feel down the back of the engine and i was told to drive the car to the local dealer - 20 minute journey - and he would follow me and drive me home after I'd dropped it there.
There was a brief delay at the dealer whilst they checked up on the car and during this time and on the journey home I chatted to the breakdown chap about what had happened. Bearing in mind that I worked as a mechanic earlier in my career, we got pretty technical about it all but to reduce it to the basics: It would seem that the earlier engines had problems with the wastegate actuator rod end where it pivots on the lever arm at the turbo end of the rod. It seizes up and grips the spindle very tightly. So tightly in fact that in many instances it can not be removed. Of course because it seizes it stops the actuator from being able to open and close the wastegate so overboost occurs which initiates "limp". Apparently if you get it early enough sometimes WD40 (other products are available) will win you some time by temporarily freeing it up but it gets so hot it'll soon burn off and a wee while later you'll be back where you started. They seem to have sorted this by producing a modified linkage. However in many cases you'll find the seizure is so severe that you can't get the old linkage off the pivot. So thinking this can be cured by just fitting the new linkage/actuator may not be possible and that's why it's not unusual to require a complete new turbo. The new turbos are all now supplied complete with the modified linkage.
When I got home I started thinking about this - I wasn't too worried because it was being done under warranty but if you're paying for it yourself there's a big pot of cash at stake. I've "messed about" sorting wastegates on a few turbos and even replaced a few that have "expired" although turbos were pretty much only found on diesels when I was on the tools. As far as actuators go, I've seen "rattly linkages" due to wear and blown diaphragms in the vacuum units (not any real world experience of electrically driven actuators though) and I just thought this "siezed linkage" scenario sounded very unlikely so I rang the garage and asked if they would keep the old turbo so I could understand what had happened. They seemed surprised (I dare say not many customers are that interested) but agreed (Arnold Clarke Seafield). Then I thought I'd ring our local independent who confirmed this to be the
problem with them and that they have done a fair few complete turbo changes because of it.
So how do you identify the new (modified) linkage. Quite easily actually. With the engine cold (It gets mega hot down there!) feel down the back of the engine for the actuator rod. follow it along to the wastegate spindle. There is a connection on the end of the rod. Is it "blocky" and square/rectangular? then it's the old type. The new one is semi spherical, a bit like a rose joint. When I went to pick up the car I had a feel down the back of a new one in the showroom - while the salesman was distracted elsewhere - it was fitted with the spherical end. My old turbo had a completely seized end. There was no way it was coming off.
Hope that helps?