[JJJ DA]

does anytime ESP light is on, you can't dialog with engine ECU?

 

[JJJ DA]

when esp control unit fails, can bus line goes down. then no communication with engine ecu. you have an oscilloscope? just compare can lines when esp light is on and no dialog with engine ecu. check the wiring diagram, maybe yours is something like that.

 

[JJJ DA]

looks like are failing some glow plugs and additive tank looks empty or pump fail. try not to regen until you solve these issues. with these DTCs, ESP light will pop for sure, but you should dialog with ESP ecu