Mercedes CLK system readiness issue

I had a similar issue with my old Volvo after getting it diagnosed. The system readiness not complete thing can be a pain. Usually it means some of the car's internal tests haven't run since the diagnostic tool cleared the codes. Have you driven it much since then?

Yeah, I've put maybe 100km on it since. Should that be enough? Is there something specific I need to do to get it to complete?

100km might not be enough, it depends on the drive cycle. Some tests need specific conditions like highway driving at a constant speed. It could also be a genuine fault preventing the tests from running. If it doesn't clear after a decent amount of driving, I'd suggest getting it checked at a workshop. They can force the tests to run and see what's failing.

Thanks, I appreciate the input! Turns out, after ignoring it for a few days it just went away on its own. No costs involved. Seems like it just needed time to reset after the car diagnostics thing. Hopefully this helps someone else.