Stuck in Limp Mode

Hello, I have a 04 Jetta BEW and it is stuck in limp mode with no codes coming up. First of all I thought limp mode simply kicked the turbo off, but it does not. What actually happens when the motor goes into limp mode? Seems to me that it cuts the fuel back to limit the power. To give you some history of the vehicle, it sat for a very long time because the previous owner could not obtain the title. When I got the car running it had “gremlins” in it. The door ajar light would stay on, then the seat belt light, and sometimes the cruise control would not work. Moreover, a fair amount of times when I would start the car it would seem the computer would not pick something up when going through the diagnostic mode, and it would be in limp mode, until I would reset it by turning the ignition off and back on. It did have an issue with the MAF sensor, if I would clear the codes and it went into limp mode twice the check engine light would come on and lodge a code pertaining to the MAF sensor. Over time it started going into limp mode while driving the car normally without an over boost condition. Now it is in permanent limp mode without any codes coming up. Is limp mode a program, like a fail safe, stored in the computer? If it is then my computer may be bad. When I run it through vag com I noticed the MAF value was 400 something which seems high to me, but does not list any values like my 01 did with vag com. Anybody ever run into something like this?

Limp mode was mechanical in both cases I had with my BEW. The first one was the bottom hose on the IC had come loose. The 2nd was a rusted out actuator on the turbo.
The loose hose did throw a P0101 code and there was lots of black smoke.
P2565 I think was the turbo actuator.