The range extender did not turn on while I was driving the car. When the range extender failed to work the car slowed down from 70+ mph to as low as 7 mph in minutes. The car then limped along for several minutes at this dangerously slow speed until the range extender turned on. Once the range extender began working, the car took off like a rocket, going from 7 mph to 70 in seconds. There are no warning lights or indicators in the car that show if the range extender is going to turn on or if it will fail to turn on. This has happened four times while I was driving on a a highway and once while I was driving on a road with heavy traffic. The first instance happened in [XXX] on my ride back from a conference. The car seemed fine for a bit until it began happening regularly in the summer of 2024*. Each time the range extender should have turned on, it failed to do so and the car came to a dramatic instant slow down posing a danger for me and the drivers nearby. The danger was once again realized when the range extender would finally turn on the car car would dramatically propel forward within a matter of seconds. I took the car to the dealership on 10/1. I intentionally ran the battery down because I wanted the mechanic to experience the problem. The shop foreman was able to experience the problem that day and he also caught it on video so he could show it to the BMW engineers. My car remains at the dealership awaiting a new battery. I am told this will fix the problem but I am concerned this will happen again. I am also equally concerned this has or will happen to others. This dangerous situation comes on without warning and could cause a major accident and possibly death to the people in the vehicle and people in vehicles nearby should the range extender fail to start. * While I experience this five times, I can only provide two exact dates this occurred. The first date of [ZZZ] and the final date (before taking the car to the dealer) on [XXX]. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA ODI 11638411