OK guys, I know that this code had been covered but my situation seems to be unique. First, my truck is totally stock 5.9. I get this code when pulling a trailer, usually up hill or accelerating, and the code kicks in just as the truck is shifting back into high gear. And I do get a check engine light and also get de-fueled.

Here's what I have done/checked:
1. I have swapped out MAP sensor with no change.
2. I can move the wastegate easily by hand with a vise grip.
3. Wastegate solenoid/command module tests correctly at over 6 ohms resistance and "clicks" when 12v is applied to wires.
4. Wiring harness from ECM to wastegate solenoid tests negative for broken wires (shows resistance on an ohm meter)
5. The pressure hose from the solenoid to the actuator looks good and still has factory clamps so I'm a bit hesitant to remove it.

Any ideas where to check from here?

Thanks
​​​​