Mini One Diesel Engine Issues

Sounds like a potential issue with your fuel injection system. Does the engine misfire at all? Check engine light plus stalling points towards a sensor problem, possibly the fuel regulator itself. Have you checked for any error codes?

Engine misfire does occur. Where exactly is the fuel regulator located on the Mini One's diesel engine, and is it something I could inspect myself without specialized tools?

The fuel regulator is typically attached to the high pressure pump. Visual inspection might not reveal much without diagnostic tools. Given the engine misfire and stalling, it's likely the high pressure pump is failing and taking the fuel regulator with it. I'd recommend a workshop visit for proper diagnosis.

Thank you for the information. The workshop confirmed the fuel volume regulator was defective, likely due to a faulty high pressure pump. The repair was completed at a cost of 1510€.