On the euro 5 there's 2 sensors, 1 is engine oil pressure switch 2 is engine oil quality, level and temperature switch.
The above aren't listed on the euro 6 custom 2.0l engine (not that i can find
)
There's are these tho.
1. fuel filter heater/wif.
2. 3x egr temperature sensors.
3. Reductant (adblu) injector.
4. Reductant heater assy.
5. Pcv valve heater element.
6. Nox sensor and module.
Lot of things need heating lol lot of things that rely on correlating info back to pcm but which can also not correlate to throw a hissy fit.
Oil gets carbon from the bores as it washes them, that's why it goes black, carbon dries the liquid in the oil so if left long enough the oil goes like crude and stops being fluid and stops being able to travel around the engine at high velocity, cooling and lubricating it.
That's the basics anyway. I don't know exactly what is telling the pcm that the oil is rubbish, the oil level and quality sensor works using resistance, resistance up the height of the sensor tells it what level we have, resistance also tells it what temperature the oil is and also what quality, perhaps even measured timed would work fluid oil spill move up and down the sensor faster. But that's a guess really lol.
Anyway that's the info i have.
There may still be sensors as above that aren't on the pcm diagrams etc but the fact is we have limited info and they are all under warranty anyway so just take it back and let the dealers sort it out
If anyone is feeling brave then when it flags up sh*t oil, get the oil changed, see if the warning goes on its own?