Could be an indication of a poor connection at the starter, battery, or jump start port. Could also be an indication of a battery that is not good, or needs to be recharged (low voltage). If the battery voltage level is low, I would check the charging system to make sure it is working properly. Lastly- if the battery, connections, and charging system check out fine - the starter itself might be drawing too much amperage.

I have never had any issues with jumping from that terminal in all my years of working on these cars. It is the most direct and accessible route for power to get to the starter, exactly what you need in a situation where the car needs a jump and precisely why BMW put it there (among other reasons like coding modules). It’s in the owners manual as well as factory service data.

@@AKJeeper bmw intended yes same for my car e60 however the starter demanding amps is different than a jump charger loading up the hot circuit with no demand. issue is the with key on not starting. as modules wake up there isn't protection. protection is back by the battery. its relatively common for people to blow a module. just a thought these cars can be annoyingly sensitive. i have personal experience with this and is mentioned on forums. this is also why low battery voltage can cause these problems. voltage down amps go up lighting module goes poof.