Bad Bimmer temp
This TSB applies to 2012 BMW models E90, E92, E93 M3 equipped with the S65 engine. The engine could enter the emergency program or experience performance and rough idle complaints. Fault 2AF9 (coolant temperature sensor) may also be stored.
This could be caused by an internal fault of the coolant temperature sensor or a sporadic connection problem with the temperature sensor connector due to vibration-induced movement.
Replace the coolant temperature sensor P/N 13 62 1 433 076 and install a coolant temperature sensor harness repair kit P/N 12 51 7 847 971. Follow the ISTA D repair Instruction 12 51 xxx… exchanging plug-in contact of coolant temperature sensor (S65).
NOTE: When the ISTA system message displays: Battery voltage only “XX.XX” V, connect a charger. Note the displayed battery voltage reading in the repair order comments section.