After testing oil pressure, please do an engine oil flush with an additive(Liquimoly works well), new oil and oil filter change before putting oil pressure sensor back on and clean the oil sensor before install.
Sounds like debris is causing blockages somewhere and could cause catastrophic damage if not taken care of in time. First test the oil pressure though, maybe hire a gauge to test or go to a shop for them to check for you.
I would still flush even if the test shows that the engine has good oil pressure.
2007 VW Jetta MK5 1.9 TDI DSG,
Mods: Simple EGR delete, LED interior set up, LED rear footwell lights, LED Puddle lamps, LED Doorhandle illumination, LED License plate lights, LED Boot lighting.
Highly doubt it but could be possible. EEPROM can only be cleared by command which applies voltage to it, and it clears all the memory, not just a small sector which is the oil pressure(and if it did, it won't read lower, it would just not read anything at all), it is just a read only chip when the car is running normally and the data on it cannot be removed or rewritten unless there is voltage applied to that one pin that enables the clearing of the chip.
I have noticed with my father in law's Polo 9N, when the battery was dying, it triggered everything from knock sensor, to airbag faulty and more. With VCDS, I cleared all the faults when the battery was replaced, and no issues thereafter.
Have you made sure that the new pressure sensor is within specifications for the car, as they can all look the same but have a different range of measurement for oil pressure.
I find it strange that there is no DTC for low oil pressure. Maybe it will take a bit of time before it picks it up. Could be cluster that is faulty.
Try and clear all DTCs first(for all modules) and then check, if it is still doing that.
Is the old sensor and new sensor giving the same/similar readout? If so, then it can't be the sensor, as it is very unlikely that two sensors would be faulty. If it isn't then maybe try the old oil pressure once more and then check if the oil sensor is reading correctly, it could just be the wrong sensor.
Continuity in the wires is one thing, the wires could also be more resistive due to damage and more resistance, thus giving a lower reading.
2007 VW Jetta MK5 1.9 TDI DSG,
Mods: Simple EGR delete, LED interior set up, LED rear footwell lights, LED Puddle lamps, LED Doorhandle illumination, LED License plate lights, LED Boot lighting.
Mine did the same on my 1.6 TDI and with a bit of fault-finding (because I could also not find any visible leaks) I finally saw that the plastic housing for the thermostat was completely brittle and the water was leaking through the perished walls and gasket. I changed every single plastic housing on the engine block (there are 2 major ones) and that seemed to fix the issue.
It started as a small leak, only requiring me to fill it up every two weeks or so and then suddenly it would drop, from filled up, to below the water line within a few kilometers drive.
I think the heat and the plastic aren't good bedfellows and I don't understand why VW didn't just make stainless steel or cast aluminium housings...
Howie-WP wrote: ↑Fri Nov 13, 2020 10:09 am
Have you tried another battery? I had funny issues on my .:R32 due to a failing battery (that would appear to be fine otherwise)
Well, it could be something completely different.
Maybe the filling amount was OK but something is blocked like an oil channel, a filter, something else. The red flashing light isn't red or flashing without a reason.
Based on the information you provide it's not possible to say. I would bring it into a garage and take no risks with this.
