Looked like the last schematic and download was if it wasn’t starting.
I didn't see that anywhere, and I just read the document right through again just to make sure....
On Page 1 for all four of the -3 Diagnostic Codes (651 thru 654) it reads:-
Conditions [under which the Codes will occur] -
Engine is running. Battery voltage is normal. Occurs during injection. CPU is normal.
Notes [aka sypmtoms] - Open circuit occurs eight times or more. Engine derates. EGR (aftertreatment) stops. Intake throttle is open 100 percent. Warning Level 3. Other injectors continue to operate, which will cause increased vibration.
I think what is happening is that there is a defect in the injector wiring harness that only occurs when the engine is warmed up. This is confirmed by the fact that you can run 20 minutes from cold before the engine derates.
The problem could also be in the solenoid coils of the injectors but it would have to be 3 separate faults, one for each of injectors #1, #2, & #3. This is less likely but still possible.
I would suggest to carry out the troubleshooting procedure when the engine has been warmed up because this is the only time the fault occurs. Refer to my post above re troubleshooting "Table 6".
Be careful of hot engine components and wear gloves.