Losing throttle completely

Maybe check the throttle position sensor and the engine to cab wire harness

 

Not sure to be honest, I don't want to mislead you, somewhere by where the intercooler pipe goes in the intake (Not much help I know).
But since you said it happens when you hit a bump, maybe focus on the wiring first and it's free. Check the harness where it goes over the valve cover and around clamps, just anywhere it could rub.

 

What Cummins faults are logging when it loses throttle? I agree on APP sensor and is usually mounted on the throttle pedal. Checking the wiring from the pedal to the engine. Always start with good clean and healthy batteries and connections also.

 

By what I can see, you have a datalink issue somewhere between the engine ECM and either the transmission and or the ABS whichever is reporting road speed to the Engine ECM. Sorry don't have more, not a Volvo guy.

 

Might check your throttle peddle, too. Fly-by-wire usually has a motorized pot in the peddle assembly itself that sends a variable voltage to indicate the throttle position to the ECM. Pretty sure the TPS would be incorporated into that, since it wouldn't make sense to have another sensor elsewhere providing the ECM with the same data it's already getting from the pedal...unless government was involved in the design and execution in which case wasteful ridiculousness is SOP.

 

If it's happening when you hit a bump than it's a loose ground or shorted wire somewhere.

Double check all battery and starter connections for loose or chafed wires.