My brother has a 2015 435i, and yesterday a dashboard readout showed "Drivetrain Malfunction" and advice to drive slowly to a BMW service center. He did so and was told that he may have had a bad tank of fuel. He was also advised to use premium fuel (91 octane). Anyone else have this problem, and, if so, what were the results and outcome? Thanks.
Drivetrain malfunction is similar to a check engine light meaning many things could cause this light to come on. With out faults to go off this would be really hard to say if bad fuel could do it. My first question is what fuel test did they do to determine the fuel is bad? Alcohol content to high, fuel dirty/clouded, water separation to great? Yes 91 is recommended for that vehicle but running lower octane like 89 would hurt the vehicle but you will notice a slight power and smoothness difference.
