my530i

I concur that it's due to low charged battery. If you drive the car often, say, more than 10 miles each trip, then battery would be well charged and error goes away.
It happened to my car for the last month. I then drive the car more, and it's not come back since.

wokingBigBoy

Took me ages to fix but i got there....

Battery terminal was loose. Used a tool to smooth connectors regreased and tightened. if you can rotate the terminal when fully tight you need to modify it. I squeezed a small piece of metal in the battery terminal so it would tighten (at your own risk) or buy new terminal. Reset warning gor tge 10th time. Have not had it occur again, its been at least a year.

Thanks

balbs

That makes sense. I read somewhere that the resistance of the positive battery cable from the terminal to the end (connected in the trunk above the spare tire area) is around 2.6 Ohms. If the resistance is higher, it could trigger the passenger restraint fault.