Weird occurrence today - I was slowly reversing out of a parking spot and seconds after creeping backwards, the car cut out. It immediately restarted and drove fine. A new fault code has appeared though after that - '4923 DDE:Control Unit, Internal 16' - this appears to be ECU related although some searches suggest possible earth issues, dirty pins on the ECU or fuel rail pressure reading faults. I will have to figure out where to start with that - probably earths, engine connectors again and the ECU connectors. I hope the ECU isnt faulty - does anyone know where it is on the E61?! Although - this post suggests to start with the battery - https://www.bimmerforums.co.uk/threads/check-battery-first-fault-code-4293-internal-ecu-16.603580/
So, a brief update - its done about 3000 miles since the drowning on 5th December. Everything seems normal. The fault above hasnt occurred again and the fault code hasnt come back either. I did an oil change today and that all looked normal (no water, no mayo on the filler cap etc). I have a new fuel filter to go on but that can wait until next weekend as I have to travel later today. I also have a new gearbox cooler to go on when I remove the panels for the fuel filter - engine temps arent getting much above 82C and its down to the cooler again.
