BMU5 Illegal software operation
â–¶ How to fix
No action is needed if DTC is set a few times (1-5). If set frequently, replace ECU.
What you'll see
No driver-visible symptom recorded.
System reaction
The system performs software reset under some circumstances.
Diagnostic depth
Detection
The ECU software continuously performs checks for unexpected or illegal events.
Possible cause
Software flaws.