NHTSA Complaint #11618240 — 2000 BMW 540I

The audio suddenly stops and my turn signals also stop working. When this happens when I'm in traffic, this is very frightening because I cannot signal lane changes or turns. Turning off the ignition and restarting the car always fixes the turn signals but only sometimes fixes the audio. It usually takes several restarts before the audio works. When in the failed condition with no audio and no turn signals and the engine running, disconnecting the Dynavin D9 "ibus box" from the vehicle instantly fixes the turn signals but not the audio. It has not been reproduced or confirmed nor has it been inspected. There is never any warning before the problem appears. I have been in continuous contact with the manufacturer in California. They sent a new ibus box, hoping that would fix the problem but it did not.