I just finished replacing a thermostat housing in my 2010 S. My OBD2 code reader listed the codes just fine while running even though reader said to have engine off. Same with erasing. Engine had to be running but reader would not erase until engine was off, then said communication error when it was. Customer service with Innova told me to hit the stop/start button twice, made no difference. Anyone have some insight to this?

 

Mercedes has some "secret codes", which cannot be erased except by dealer. Don''t know about Mini

 

No secret codes here just a trick fix. I had to insert key, do not push in clutch then hit start button. Ignition energized and I was able to erase codes. Not even the OBD2 manufacture knew this.