Mini Countryman Diesel Engine Trouble

The symptoms you describe poor starting, engine stalling, and the check engine light certainly point towards a camshaft position sensor issue. Has any sensor testing been undertaken? An engine misfire can also trigger similar symptoms. When was the last time you checked the camshaft position?

I haven't done any sensor testing myself. Is there a way to check the camshaft position sensor without special tools?

Without proper diagnostic equipment, it is difficult to definitively confirm the camshaft position sensor. Given the car stalling and engine misfire, it is advisable to visit a workshop. It does sound like a sensor failure is likely.

Thanks for the help. As suspected, the garage diagnosed a defective camshaft sensor. Apparently, the encoder wheel on the camshafts was the culprit. Ended up costing me around 695€ to get it sorted, but the car is running smoothly again.