DS3 oil pressure warning light

It certainly sounds like a sensor issue. When the oil pressure warning lamp illuminates, that is usually related to temperature. Is the car running rough or overheating, or is it just the lights? Have you checked the oil level just to rule that out first?

The car appears to be running normally; I haven't noticed any overheating. I checked the oil level, and it seems fine. If it is just the lights, does that mean the engine oil temperature sensor is broken?

It does point to a faulty engine oil temperature sensor, or potentially a defective cable or plug connection to it. However, without proper diagnostic equipment, it's tough to be certain. Considering the symptoms, it would be advisable to take it to a workshop. The repair shouldn't break the bank though, I would imagine a new sensor and labour will be around 95€.

Thank you for the information. I will bring it to a workshop for diagnostics. Your insight was helpful. It turned out to be a defective cable, which cost 95€ to repair.