Not the typical throttle actuator problem?

[Mpatient]

My 08 m3 is exhibiting odd symptoms with the throttle actuator bank 1.
@ 67k. For whats its worth the dme was flashed to the newer software and the battery was changed at 62k.

The code appears only while accessories are left on for a long period of time(car off listening to music) with common symptoms of throttle actuator 2B15 bank 1, limp mode, Xmas tree dash, rpm limit..etc. No aftermarket electronics, just mp3 player via aux.

After clearing the code it doesn't reappear unless I leave the accessories on for a long period of time, I concurred the test a coupe times and left the car off while listening to music for 5 minutes and same problem but this time I didn't have to turn the car on, the code was appearing when the dme ran a throttle actuator pre-drive test and showed the same code. So again I cleared it and it hasn't appeared, I haven't had the need to sit waiting in my car with accessories on waiting for an electric gremlin. Although I have been driving the car and it hasn't had an issue.