wolf89

OK, quick update - just in case we've checked if for some reason the negative terminals (Engine/Chassis and NegBatt/Chassis) were iffy, but unfortunately both passed with flying colours. We did notice that with the BMS (fuse 9) installed, the alternator occasionally dropped to 50W at idle with a relatively discharged battery at ~14.5V, but with it disabled - it never dropped under 250W at 13.5, which leads me to believe that the negative terminal's sensor may be at fault.

Greetings all, I've got a real headscratcher of an electrical fault that's driving my dad (and by extension me) nuts in his '15 1.2 (CJZC) Rapid. Basically, the car's started randomly throwing out "12V low" and "Start Stop Error" warnings on start, despite daily drives of at least 20 kilometers of mostly non-city driving (no start/stop, AC on, only DRL). We initially assumed that the car battery may be a dud (a 4 month old Varta AGM that replaced the original EFB one that gave up the ghost) or that the garage hadn't properly recoded the BMS, but using a scan tool shows ruled that out as well. Checking for fault codes yielded nothing as well even though it was on the same engine start a yet another "Start Stop Error" warning was still on the MFD, so at this point I'm open for any suggestions on what the root issue may be and how to resolve it. Well, anything but going through the local Skoda approved garage in the old country, because those lads are beyond horrendous (as in forgot to bleed the brakes on my mom's Octi among other debacles). Not sure if this will be relevant, but: - at idle, the scantool claims a 350-400W alternator load with everything but the DRL's and a dashcam in the infotainment system's USB being turned off - absolutely no fault codes to be found by a VC700 - either as standard ODB2 or when scanning the VW-specific modules - the same scantool claims a steady 14.5V on the control module after engine start, confirmed with a simple 12V plug tester as well Soooo, if anyone has any suggestions or needs extra information to help diagnose this thing, please fire away