Hi,
I have a serious drivability problem with my 2007 E320 BlueTEC.
It only sets two codes, 2359-2 (charge pressure is too high) and 2359-1 (Too low boost pressure). What happens is that at about .6 bar of boost the system decides the boost is too high (sets 2359-2) and goes into limp mode, which opens the turbo vanes to 5% closed. This then sets 2359-1. Turning the car off and then on clears the problem, only to repeat. This has slowly deteriorated over the past year from occasionally happening at Interstate merge speed of 75 to 80 mph to happening at steadily slower speeds to the point it now happens at 20 mph. All elements of the engine function normally per activation tests with diagnostic equipment (Autel MP808). Monitoring of boost pressure and fuel rail pressure shows radical instability of readings and readings that defy logic. The Backpressure sensor and boost pressure sensor have been replaced. The DPF is not clogged, nor are the catalytic converters. I have been told to replace the turbo, which I did with a remanufactured unit with its own controller. That made absolutely no difference. See graphs below. Anyone have any ideas? ECU?

Thank you. Juergen