A rapid assessment utilising ISTA on terminal 30 or for wake-up events will precisely identify the module responsible for the wake-up and subsequent drain. If the Indy has not accomplished that, they are more incompetent than esteemed, since they might have also requested a test plan in ISTA and asked you to return a week later, with the reason of the issue documented in a log and resolved by now. Always remember, the designation of a specialist by garages does not inherently confer expertise.
I would not anticipate the auto electrician to possess ISTA readily available.
Within ISTA
Access the Power Management History
Navigate to “Vehicle Information → Control Unit Tree.”
Choose DME, CAS, FEM, or BDC according on your vehicle; typically, the F25 utilises either CAS or FEM.
Access “Power Management” or “Energy Diagnosis” and select “Power Management History.”
This record indicates:
When the car entered a dormant state
Upon awakening, which module initiated the wake-up process (e.g., “Wake-up cause: telematics control unit (TCB)” or “Wake-up cause: key request”)
This is the essential function for diagnosing battery depletion. If a particular module is consistently identified as a wake-up cause, it is the primary suspect.
To execute a testing protocol
Execute an ISTA test plan for "Energy Diagnosis" or "Enhanced Battery Discharge."
You may adhere to the on-screen guided workflow, which will display:
Documented sleep/wake patterns
Modules that inhibited sleep Battery charge log