My best guess:

That "no comm" indicated the CAN BUS was disabled (please don't say "Shorted") due to damage in the pump module. With the CAN BUS to the rear of the car inhibited, none of those modules could communicate.

George,

I'm getting good at electronic diagnostics from the kitchen table. They moved our offices and lab to Dallas three weeks ago, been working here, isolated, ever since. I move to Dallas on or about June 8.