Peugeot 408 fault memory lock active error

I have a 408 too, and I had something similar happen a while back. Do you notice anything else acting strange, like the infotainment system or any of the driver-assist features acting up?

Interesting. No, everything else seems to be working fine. Did your error also point to a memory lock? And did you also suspect undervoltage?

Yes, the error message was the same 'fault memory lock active'. I tried looking into the undervoltage, but honestly, I'm not that knowledgeable about car computer systems. I ended up taking it to the workshop.

Thanks for the info. Workshop visit confirmed my suspicion: undervoltage caused a memory lock. ECU diagnostics and reset cost me 240€. All good now!