FramusAz10

Hi everyone, I am experiencing a very specific and intermittent issue with my 2014 Škoda Octavia vRS (2.0 TDI, CUPA engine, 135kW, MQB platform). The car currently has 234,000 km on the clock. The problem only occurs while driving. The exact symptoms and sequence on the screen: While driving (the engine is already at operating temperature), the Infotainment screen suddenly shows the message: "Vehicle power consumption is too high". Immediately after, the dashboard displays: "Error: Start-Stop". At the exact same time, the engine idle speed jumps and gets locked around 1100 RPM. Together with this, I can also feel a slight resistance/subtle heaviness in the steering wheel when turning. It is not a major loss of power steering, but a noticeable change in assist. This is not a new symptom; it has always happened alongside the error. Once this happens, the high idle, slight steering resistance, and the error do not go away until I turn the car off. After restarting the engine, everything goes back to normal. This happens completely randomly (intermittently) — the car can run fine for days or weeks in between. What has already been checked and ruled out: Diagnostic Scan: Surprisingly, a diagnostic scan was performed, and there are absolutely no fault codes (DTCs) stored in the ECU or Gateway module regarding this. EGR Cooler: The EGR cooler has been replaced recently. Battery & Start-Stop: Most of the time, the Start-Stop system works completely normally (the car shuts off and restarts at traffic lights), meaning the AGM/EFB battery has good health and capacity. DPF and Injectors: The DPF has been professionally cleaned, the injectors have been tested, and everything is in perfect condition. DPF Regeneration: When the error occurs and I pull over to turn off the engine, the radiator fans are NOT running on high. The car goes quiet immediately, so a cancelled DPF regeneration is definitely ruled out. Because of the specific warning sequence (High consumption → Start-Stop Error) combined with the subtle steering change, it is clear there is a genuine, temporary voltage drop in the system. I strongly suspect either a bad alternator freewheel pulley, an intermittent fault in the alternator voltage regulator, or a loose/oxidized main ground strap. Has anyone experienced this exact issue on the MQB platform, and what was the root cause in your case? Any advice would be greatly appreciated before I take the car back to my mechanic. Thank you for your help!