Intermittent white smoke
I have this truck no codes customer estates when taking off he'll notice white smoke and lack of power and the transmission wont upshift. In the pass we have replace the intercooler to the updated part number per tsb. where water will condensate inside in damp or wet weather. More recently we replace the throttle body for egr codes and thermostats because the engine coolant temp was keeping the truck from doing the exhaust regen. There is no coolant lost to suspect egr cooler failures, the only thing i found so far is information about white smoke while the truck is doing the regens. If this is the case why it would be doing more than one regen in the last 200 miles. this truck is not used for towing or any severe driving conditions.
Monitoring Regen pids may explain multiple regens. There should be a Distance since regen requested and distance since last regen completed. If the completed distance is longer than that of the request it would mean the previous regen did not complete.
Many times loss of power with no codes means a fuel or boost issue. I'd be starting there. Trans won't shift if there's a lack of fuel or a boost leak.
I checked for boost leaks and the turbo as well it makes over 30 psi in boost and i have checked the inside of the intercooler for oil pooling at the bottom. only time he notices the smoke and lack of power has been taking off from a stop sign intermittently one the trucks is moving at there is plently of power.
The fact that it loses power and trans won't shift suggest to me that there is a fuel issue. Trans won't shift if it's lacking boost and it can't make boost if it's lacking fuel. Can you duplicate the condition? Connect a fuel gauge and a scanner and monitor the data during the event. You want 5 - 10 psi supply pressure and see that actual vs desired rail pressure match up.
White smoke,,,, Check the short term fuel trims on the injectors. Those engines are notorious for bad injectors. If perchance an injector is injecting fuel on the exhaust stroke, and the DPF has a crack in it, you can get the white smoke (atomized unburned fuel) which is blown out of the tail pipe. Those engines are a Pile.