CLK Fault Memory Lock Active Message

My 2009 Mercedes CLK with a diesel engine has thrown a strange code. The computer system is reporting 'Fault memory lock active'. I've got 235707 km on the clock. All I know is that there's some error stored in the fault codes memory. I suspect it might be related to undervoltage at some point. Anyone seen this before?

4 comment(s)

I had something similar happen in my CLK (petrol engine though). Check your battery and alternator. The control unit can throw weird codes when the voltage dips. Did you recently have any work done on the electrics, or has the car been sitting for a while?

Battery seems fine, and the alternator is charging. Nothing electrical done recently, and it's my daily driver. When you say 'similar,' do you mean the 'fault memory lock active' message specifically, or just random fault codes? Did you manage to clear it yourself, or did it need special tools?

Yeah, I got the same 'fault memory lock active' message. I tried clearing it with a basic OBD reader, but no luck. Ended up taking it to a workshop; they said it was a voltage issue that corrupted something in the computer system's memory. They had to reset the control unit. Best to get it checked; could save you a headache.

Thanks for the heads-up. Sounds like I'm heading to a workshop then. Just got a quote, and it looks like it's going to be 240€ to sort it all out, so thanks for confirming it's not a simple fix.

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