I have the blinking glow plug light and limp mode on my 2010 CR TDI. I read all the DIY threads regarding limp mode and the N75 solenoid and the VNT actuator. My actuator was bad so I replaced it. I thought this would fix my problem but it hasn't gone away. I've done the tests in VCDS for the actuator, and it moves from .75V to about 3.75V. The sound of the exhaust changes, and the vane actuator lever was very easy to move my hand when the actuator was off. This tells me that my actuator is working properly. There are no leaks in my vacuum lines, and no boost leaks. I have noticed a loud, whining/squealing sound coming from the turbo when my problem started. I'm beginning to think my turbo is bad. I tried to take the car for a drive when I replaced the actuator, but I still have no power and threw another "boost not reached" code. The N57 solenoid is pulling a vacuum on the actuator, so I don't think that's the problem. I went into the measuring blocks to see the specified vs actual boost, and it definitely looks like the car isn't building the boost that's specified. What do I need to check from here? How can I check the turbo itself? I want to be sure I need a new turbo before I go through the hassle of taking it off and buying a new one. There's 130K on the car and no turbo oil leaks.