The Diagnosis for the 204 Model series is switched off as from diagnostic data version 06/2009 in the DAS. A Password is required for diagnosis using DAS.
SI-Reset MB38 service intervall reset works with Mercedes Benz cars with 38 pin connector except ML class, it helps resets the Service Indicator (Service Intervall) , and delete airbag faults (if your airbag warning light is on you can turn it off with this tool, if the error is not a permanent one)