870 turbo overspeed cel

[Chamberpains]

Also check the air piping and actuator on the turbo for leaks. I just recently had my actuator leak at certain positions but not under full extension (like it is when using Insite actuator test mode) It was also causing the ECM to over correct intermittently with really erratic boost pressures and pretty violent spikes. I never got overspeed codes though. Then it finally gave up the ghost and completely blew the actuator seal and I was able to find the leak using Insite actuator test mode.