Servus! The day before yesterday, unfortunately, I had a breakdown on the road during normal operation. At approx. 100km/h in cruisen a CIC message came up with the information that you should park the car and insert “P”. 5-10 seconds later, the CIC message “drive defective” came and again about 10 seconds later, it simply went out. Starting attempts were then unfortunately unsuccessful. One hears, however, that the starter wants to turn, but it does not make it. So exactly there the sound like when the battery is completely dead. Car was then towed home to me and I then read it out with ISTA. In the error memory were 15 error messages, which however all had to do with strong battery undervoltage (pictures in the annex). So things like No communication with several ECUs possible due to undervoltage, <9V on-board voltage etc. After the deletion of the codes and external charging of the battery (must expand the battery because where the A uto had no current and foreign start attempts were unsuccessful) but the fault memory was already empty again - battery full, also at the charging poles in the engine compartment I have full voltage attached, nevertheless only the "crack" during the start attempt. Also again with foreign start aid only a very meager slow turning of the starter (he turns however by far too slow for a start). The whole error picture is so strange, since error memory is empty and it does not start despite foreign start help b between the starter turns decent. I am really unplanned.... would be happy about all the information/suspects. Have ISTA for driving, reading out etc. LG