Mercedes A Klasse Diesel Starting and Stalling Problem

I also have an A Klasse and had similar issues: hard starting, stalling, and the check engine light. It does sound like the camshaft sensor. My engine misfired a lot. Have you pulled the diagnostic trouble codes (DTCs) from the ECU? That would give you a good idea of what's going on.

I haven't checked the codes yet, but I suspect it's the camshaft position sensor. Was that the fix for you? What was the cost?

Yes, replacing the camshaft sensor fixed it for me. Because our issues sound so similar, I'd recommend getting a mechanic to diagnose it. Trying to fix it yourself could make things worse and more expensive. I took mine to a workshop.

Thanks. It was the camshaft sensor. Cost me 695€ to fix. Glad my guess wasn't too far off.