2003 E320CDI OM648 - Limp Mode - Turbo Actuator?

[Richteo]

Morning, following a thermostat change a couple of weeks ago where I lazily didn't drain the coolant I've been suffering with the car being stuck in limp mode. I mention the thermostat change as I hosed off the spilt coolant after the job, possibly a costly mistake.

The stored and current code according to icarsoft that comes back is:
P2110 Y100/1 Right charge pressure positioner, Sort circuit to positive. I've disconnected the electrical connector, cleaned everything up with contact cleaner and reassembled, with no change.

If I leave the turbo disconnected the fault code changes to :
P2112 Y100/1 Right charge pressure positioner, Signal line is interrupted.

This leads me to conclude that the actuator is indeed fried rather than an actual wiring problem. Does the logic stack up or is there anything else to check?

 

[LBZDreamer]

The actuator is indeed faulty. When the car is running, the computer sets the voltage on the control wire at 12v and will pull voltage to 0V to move the actuator rod since it's controlled via PWM. I used a oscilloscope to see if my actuator was indeed working since I got a low boost code. turns out it's communicating fine and the electric motor stop functioning.

 

[Richteo]

Thanks for taking the time to respond. I've only driven the car once a week since it first started happening, before hopefully getting some time over Christmas to investigate further. It is basically a spare car now.

Last weekend the turbo was fine, back to normal until the car was fully warmed up and then the same code struck again. But the first time I kicked down I got a P1222 code I think with either voltage or plausibility code for the throttle pedal. This made me think that maybe it is an electrical fault (poor earth/ground?) rather than a turbo actuator fault. The earth point is the same for both on the inner wing but it also earths the whole CDI3 ECU so I would expect more faults.

This weekend no sign at all of any boost/turbo issues, but pedal issue persists. I've ordered a used pedal and intend to clean all grounds, battery negative, hose down the ECU connector and turbo connector with contact cleaner and take it from there. I don't really want to have to get into continuity checks for all the harnesses!