Mercedes M Klasse Diesel Fault Memory Lock Active

I had something similar happen with my M Klasse. Is it affecting anything noticeable? The error code might point to a deeper issue, or it could be a glitch. By 'memory lock', do you mean you can't clear the ECU fault?

Yeah, that's right. I can't clear the error from the memory. So you think it's happened to you too? Was it really just undervoltage, or was there something else going on with the car electronics? Did you also have the active memory message?

Yes, I had the 'active memory' message as well. Ended up taking it to a workshop. They said it was likely the undervoltage causing the ECU to act up and lock the memory. They reset everything and checked the charging system.

Thanks, that's helpful! Sounds like I'll need to bite the bullet and take it in. I was hoping to avoid it, but it's better to be safe than sorry. Workshop confirmed, it was indeed undervoltage causing the issue. Repair cost: 240€. At least it's sorted now!