The “Transmission Malfunction” light will come on when the car suspects there to be a problem with the transmission. Your car will typically put the car into “limp mode” when this light comes on.
Most BMW’s should have their oil changed every 7,000 miles. The factory recommendation is usually for twice that mileage but from our findings that is far too long. We’ve inspected the internals of BMW engines with only 80k miles on them that have been following the factory oil change interval and found massive sludge build