Kubistar Overheating Bypass Valve Error

Overheating alongside a bypass valve error could indicate a problem with the air intake or vacuum system influencing the fuel efficiency. Is the engine stalling at all? The bypass valve's function is to regulate airflow, and its malfunction can indeed lead to overheating. However, a "consequential error" suggests a different underlying fault. Have you checked for any other error codes? What is the exact error code?

No stalling as far as I can tell. And no, I didn't check for other codes before clearing the error history. Would a faulty sensor cause this, or is it more likely a mechanical issue?

Given it's a diesel and exhibiting those symptoms, I suggest a thorough diagnostic check in a workshop. While a faulty sensor could be involved, the overheating combined with the bypass valve error points to a more complex problem within the vacuum or air intake system. It requires careful inspection. The stored error points to a more subtle issue, and can lead in certain situations to engine stalling or a decrease in fuel efficiency.

Appreciate the detailed explanation! Turns out it was a consequential error. There was another error stored, which I didn't notice. After fixing that one, this bypass-valve-error was gone - repair cost was 0€!