While driving on the interstate, the drivetrain malfunction warning appeared causing the car to become ‘limp.’ This limp mode caused a sudden inability to accelerate in a lane requiring mobility to avoid collision with merging right lane traffic. If this car had not already been in the far right lane, it would have potentially cause a serious hazard in a high traffic area. Prior to this drivetrain warning, the vehicle had been serviced at BMW twice in the past 6 months. December of 2024 the battery was replaced. All 4 run flat tires were purchased new in April. By the end of April this drivetrain malfunction occurred requiring a tow back to BMW. Initially they diagnosed the battery as bad, though I informed them that shouldn’t be happening since the battery was purchased just a few months prior. After more testing, I was informed that the battery is fine but the throttle body is draining it. This is a part that should last throughout the life of the engine. I asked if there was any way this could have been diagnosed during previous service, as this is a serious failure and had I not told them I already bought a new battery I would have had another incorrect diagnosis and further engine damage.