Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
I have an owner of the above mentioned vehicle asking what "SERVICE BK exceeding 135 days mean". According to him he bought the MB about 1 1/2 years ago and was pretty sure service was done - coolant, engine oil, brake fluid, as well as tranny oil /filter flush. Is there a way to RESET/ERASE it or does he have to have fluids flushed again. I am not familiar with MB procedure.