[Admiral Awesome]

Hello internet compatriots! I've been having some trouble with my chariot (2016 BMW M135i), and I was hoping you may be able to help me troubleshoot potential solutions.

The issue initially flagged as a headlight issue - I was driving, the headlights flickered momentarily and a warning popped up "left headlight high beam failure" or something along those lines. The car was already scheduled for an unrelated service so I asked them to check it out. They pulled off the headlights, checked all the wiring and couldn't find an issue, nor could they cause it to fault.

A few days later, there were a cascading series of faults, all centered on the headlights. A follow up visit to the mechanic resulted in the suggestion that they thought it might be a 'K-CAN' network fault, and that to diagnose where the issue was coming from, they would need to car for a few weeks and an oscilloscope(?) to identify the fault.

Given the likely expense of this approach, I opted (with the help of posts from other forum members - thank you one and all) to install ISTA on my laptop and get a read out of the errors for myself. The attached pictures were the result.

The following was a list of the faults:
801 C20 ZGM: central fault memory full - no control-unit fault
804014 No supply voltage to Terminal 30L2
8041B6 LWR system faulty
8041 BA AHL system faulty
804890 Turn signal plausibility check failed: Function deactivated
80598C Low-beam headlight 1: Short circuit to B+
805BOD Low beam headlights: Short circuit to B+
CA9428 Message (PDC function, Ox377) incorrect, receiver TRSVC, transmitter PDC / REM
CDB804 No message (request, A/C, Ox2F9), receiver DME/DDE, transmitter IHKA
D0181F Signal (navigation graph, 253.3.4) invalid, transmitter HIJ/ZGM
D0183F Signal (navigation graph, speed, 254.2.4) invalid, transmitter HIJ/ZGM
D01914 Signal (synchronisation, navigation graph, 253.0.4) invalid, transmitter CHAMP, Cc, ZGM
D64468 TBX: K-CAN2, communication fault
D8C468 ASD: K-CAN2, communication fault
D8D400 No message (data, drive train, 2, Ox3F9), receiver ASD (K-CAN), transmitter DME/DDE
D8D401 No message (crankshaft torque 1, OxA5), receiver ASD (K-CAN), transmitter DME/DDE
D90C13 LIN-bus headlight driver modules: No communication
D90D2F Headlight driver module (TMS) left (LIN): No LIN-slave
D90D32 Headlight driver module (TMS), right (LIN): No LIN-slave
D91DEO No message (status outer light front electronics 1 left, Oxl EO), receiver FEM, transmitter TMSL
D91DE6 No message (status outer light front electronics 1 right, oxl EO), receiver FEM, transmitter TMSL
D91DFB No message (status, exterior lights, front electronics 2, left, oxl FB), receiver FRM, transmitter LHML
D91DFD No message (status, exterior lights, front electronics 2, right, OxlFD), receiver FRM, transmitter LHMR
D91E46 No message (status, front air conditioning control panel, Ox246), receiver FEM, transmitter IHKA
D91EBF No message (control, water valves, Ox2BF), receiver FEM, transmitter IHKA
D91EDF No message (status, rear wiper, Ox2DF) receiver FEM, transmitter REM
D91EE5 No message (status, rear outer light, Ox2E5), receiver FME, transmitter REM
D9C45F FLEL, K-CAN2 line fault / electrical fault
D9D401 No message (exterior light 2 control, Oxl E4), receiver FLEL, transmitter CAS / FEM
DA045F FLER, K-CAN2 line fault/electrical fault
DA1401 No message (exterior light 2 control, Oxl E4), receiver FLER, transmitter CAS / FEM
E11454 No message (raw data, fuel tank level, Ox349), receiver KOMBI, transmitter JBE/REM/BDC
E1445F TCB: K-CAN2 or K-CAN4, line fault / electrical fault
El C468 HU-H: K-CAN2, communication fault
E2C468 CON: K-CAN2, communication fault
E2D400 No message (dimming, Ox202), receiver CON, transmitter FRM / FEMZGM / BDC-ZGM
E2D401 No message (vehicle condition, Ox3A0), receiver CON, transmitter JBE / FEM-ZGM / BDC-ZGM
E2D403 No message (terminals, Oxl 2F), receiver CON, transmitter CAS / FEM-ZGM / BDC-ZGM
E58468 REM, body CAN2: communication fault
E5940A Message (turn indicator direction, Ox257) incorrect, receiver REM, transmitter FEM
E71406 Message (data, drivetrain 2, Ox3F9) missing, receiver IHKA, transmitter DME/DDE
E7140 E Message (crankshaft torque 1, OxA5) missing, receiver IHKA, transmitter DME/DDE
E71411 No message (units, Ox2F7), receiver IHKA, transmitter KOMBI
E7141E No message (terminals, Ox12F), receiver IHKA, transmitter FEM / BDC
E71465 No message (configuration of switch for driving dynamics 2, Ox3E6), receiver IHKA, transmitter DSC / ICM

I'm kind of hoping to avoid an exorcism here (of my car or my bank account). Is it reasonable to assume the mechanic was correct in that it's a K-CAN fault? Also, is there a way in which I could try to narrow down the source of the fault myself? I don't know if it's significant, but the only overt symptoms of an issue are the recurring headlight errors.

Any help most appreciated.