Mini One diesel water sensor issue

A rough running engine coupled with a water sensor error on a Mini One Diesel Intriguing. First, have you checked the sensor itself for any physical damage? Is the sensor connector corroded? Also, what diagnostic trouble code (DTC) is the system reporting? Providing the specific code would be immensely helpful. Furthermore, could you describe the 'rough running' in more detail? Is it constant, or does it occur under specific conditions, such as cold starts or acceleration?

Thanks for the quick reply! I haven't seen any visible damage, but the connector could be corroded, I'll have to check that again. The error code I read out was P1470. The engine runs rough all the time, but it's especially noticeable when it's cold. Any further thoughts based on that?

P1470 does indeed point towards a potential sensor issue. Given the age of your Mini and the symptoms you describe, the 'likely cause' assessment you mentioned – a defective cable or plug connection – is plausible. Moisture can wick into connectors over time, causing corrosion and intermittent faults. However, a failing sensor cannot be ruled out entirely without further diagnostics. Considering the potential complexity and the relatively low cost of repair, it might be prudent to consult with a qualified auto electronics technician or a workshop equipped with the appropriate diagnostic tools. They can perform a thorough inspection of the wiring harness, connector, and sensor functionality to pinpoint the exact source of the problem.

Just wanted to update you: it was indeed the water sensor connector. The mechanic cleaned the contacts, and the error is gone. All in, cost me 95€, which I'm happy with. Thanks for your insights!