Scenic transmission error

Okay, that's quite the laundry list of symptoms. 'Radiator oil pressure defective' isn't exactly a common code. Are you sure about the code description? Radiators typically carry coolant, not oil. You might want to double-check it or see if it's perhaps related to the transmission cooler lines that sometimes run through the radiator. Also, since you mentioned jerky shifts and grinding, have you checked the transmission fluid level? Low fluid could cause similar issues. The cooling fan itself wouldn't directly cause those symptoms.

Thanks for the quick reply! You're right, my bad, it's probably the transmission cooler lines! So, if the transmission cooler line is acting up, could that really cause the 'radiator oil pressure' error? And how exactly do I check the transmission fluid level on this thing? I'm still a bit clueless about whether it's a coolant leak, so any tips would be welcome!

Alright, 'radiator oil pressure' pointing to the cooler lines makes more sense now. A defective cable or plug connection of this component is very likely, and definitely could throw that error and cause the transmission to act up. As for checking the trans fluid, it depends on your exact transmission model. Some have dipsticks, others don't and require a specific fill procedure, often done from underneath the car. Honestly, with all those symptoms and the potential for serious transmission damage, I'd recommend taking it to a workshop to get it properly diagnosed. A cheap fix now could save you from a very expensive transmission rebuild later. They should be able to pinpoint the pressure issue as well as any potential coolant leak from the cooler line.

Thanks so much for the advice. I took it to a local shop, and you were spot on! Turned out to be a faulty connector on one of the transmission cooler lines. New connector, fresh transmission fluid flush, and everything's running smoothly again. The final repair was 95€.