Coolant sensor stuck
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2010 BMW M6, 2010 BMW M5, 2009 BMW M6, 2009 BMW M5, and 2008 BMW M6. However, it is still accessible from the selected car via links, so may be relevant.
This figure represents the none proper working coolant system system. The coolant sensor is stuck at 30 deg C.
Description of the curves:
The ECT does not increase the temperature. The coolant temperature model increases like expected. At a certain time a malfunction for a stuck sensor is set and the coolant model temperature is used as reference for the coolant temperature.