Corsa Oil Pressure Warning

That does sound frustrating! The error code indicating a faulty oil level sensor signal, along with the warning light and error message, definitely points towards that sensor or its wiring. Before replacing the sensor, which can be a bit of a pain depending on its location, have you checked the wiring and the connector to the sensor? A loose connection, corroded terminal, or damaged wire can cause the same symptoms as a bad sensor. Also, some vehicles have a combined oil level and temperature sensor. Does your Corsa show oil temperature readings? If so, are those readings plausible?

Good shout about the wiring! I had a quick look but didn't see anything obvious. Where exactly should I be focusing my attention? Is there a common spot where the wiring might rub through or get damaged on these Corsas? And yeah, I think it does show the oil temp... where would I find that info and what sort of temperature would be 'normal'?

Okay, given that you've seen the warning and have an error code that indicates an issue, and you've checked the wiring superficially, it's still quite likely the issue lies within the wiring itself. Focus on the connector that plugs directly into the sensor; check for corrosion, bent pins, or looseness. Trace the wire back as far as you can, looking for any points where it might be chafing against the engine block, chassis, or any other moving parts. Regarding the oil temperature, that information is usually displayed on the infotainment screen or within the instrument cluster menu. Normal oil temperature for a diesel engine, once warmed up, is generally in the 80-110 degrees Celsius range. If the temperature reading is way off or erratic, that would further suggest a sensor issue. Given the symptoms, and without more in-depth diagnostics, I'd recommend taking it to a workshop.

Cheers for the detailed advice! After fiddling with the plug connection, it was still showing errors, so I bit the bullet and took it to a local garage. Turns out you were spot on – it was a defective cable or plug connection to the sensor, they sorted it for 95€. Thanks again!