SOS MALFUNCTION DISPLAYED This Service Information Bulletin (Revision 1) replaces SI B84 04 16 dated September 2016. One or all the following may be experienced in the vehicle: An SOS malfunction is seen in the Kombi (aka instrument cluster) When pressing the E-Call/SOS button in the overhead console nothing happens Fault code B7F33C (internal ECU error) is stored in the Telematics control unit (ATM/TCB2) There are 2 known causes for this failure. They are as follows: Software file missing from the ATM/TCB2 control module Water leak at the "shark fin" roof antenna (aka roof aerial) leading to corrosion in the ATM/TCB2 control module.