Why can't the BMW e66 start?

[AliyahLee]

BMW e66 cannot start due to operational reasons or battery depletion. Operational reasons: Poor usage conditions, such as long-term parking without use; unfavorable driving habits, like frequent short-distance trips; leaving the ignition switch or audio system on for extended periods after engine shutdown; or keeping side lights, parking lights, or emergency lights on while the vehicle is off can all lead to failure to start. Battery depletion: Battery depletion is a common issue in BMW models, often caused by the vehicle failing to enter sleep mode, resulting in excessive discharge current and ultimately preventing the car from starting. For this type of fault, the elimination method is used to systematically identify the issue in a logical sequence. First, check for any additional aftermarket devices installed (such as navigation systems or radar detectors), then inspect the vehicle's communication and entertainment systems (like the audio system or phone), followed by the control modules for each door and other electrical components, and so on until the fault point is located.