Saxo Fault Memory Lock

I also own a Saxo, and I experienced a similar issue some time ago. If I remember correctly, the 'Fault memory lock active' message often indicates an undervoltage situation that the ECU has detected. Has the car been sitting unused for a while, or have you noticed any other electrical oddities, like the lights dimming?

Thanks for the quick reply! Undervoltage, huh? That's interesting. The car has been sitting a bit more than usual lately, now that you mention it. But wouldn't that just mean the battery is a bit flat? And what exactly is the ECU?

Prolonged periods of inactivity can certainly lead to battery drain and subsequent undervoltage. The Engine Control Unit (ECU) is the car's central computer, managing various engine functions. When it detects undervoltage, it can sometimes lock the fault memory to prevent further issues. Given the symptoms and the potential cause, I would advise having the vehicle inspected at a workshop to address the underlying undervoltage issue and clear the fault memory using diagnostic equipment.

Okay, I get it now! ECU undervoltage lock makes total sense. Sounds like I'm off to the workshop then. They found the fault and reset the ECU with the diagnostic tool, turns out that the fault memory lock active was due to an undervoltage in the vehicle. The repair cost me 240€.