Between single/3 plugs there's very little difference other than the connectors on the bottom. The software structure is a bit different, but it's still the same EDC15C2 - all EDC15s use pretty much the same microcontroller and architecture. The main differences as mentioned is the increased EGR control with the doser valve.
The later car probably has less worn solenoids and internal valving - I suspect that the amount of fuel injected is out of calibration, thus injecting more at short durations - this is what causes the fabled injector "rattle", it's not the injectors themselves making the noise, it's due to an uncontrolled pilot/main injection causing the pressure rise to be too great, causing that characteristic rattle you hear.
The later car probably has less worn solenoids and internal valving - I suspect that the amount of fuel injected is out of calibration, thus injecting more at short durations - this is what causes the fabled injector "rattle", it's not the injectors themselves making the noise, it's due to an uncontrolled pilot/main injection causing the pressure rise to be too great, causing that characteristic rattle you hear.
