maxstern37

Mercedes M Klasse System Readiness Issue

My Mercedes M Klasse, build year 2007, diesel engine, with almost 300000 km, keeps throwing an incomplete system readiness check. There's an error stored, and the speedometer is showing a warning. It all started after I ran an OBD2 diagnostics check. Any ideas? I suspect it might have to do with the onboard diagnostics.

4 comment(s)

I had something similar happen on my older BMW. The check engine light was on because the OBD readiness monitors weren't set. Try completing a drive cycle. It might take a few tries for all the monitors to register as ready. Did you recently clear any codes?

A drive cycle, huh? How exactly does one do that? And yeah, I cleared the codes when I did the OBD2 scan. Could that be the reason for the exhaust system issues?

Clearing the codes definitely reset the OBD readiness. The drive cycle is basically a specific sequence of driving conditions that allows the car's computer to run all the necessary tests. Google "OBDII drive cycle" for your Mercedes, you should find the exact procedure for your model. But if it doesn't work after a few attempts, a visit to the workshop might be unavoidable.

Thanks! I followed your advice and found the drive cycle procedure. Turns out that was exactly the problem. I completed the cycle, and the system readiness check is now complete. The error message disappeared. No repair costs needed! Appreciate the help.

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