The Mercedes-Benz Flexible Service System (FSS) is installed in the vehicle and informs the car owner when service is due and what type of service is needed. Because the timing of the reminder is based on that person's driving style, the service schedule is considered flexible.
Starting about one month prior to the service due date, the maintenance service indicator notice appears in the multifunction display within the instrument cluster. That notice specifically tells the driver how many days remain until the next service due date. The notice also displays the type of service needed. The most common service types are Service A (basic service) or Service B (extended service). Depending on the vehicle age and model, the service type can go up to Service H. If the owner does not have the necessary service by the due date, a wrench symbol appears and informs the driver how many days has elapsed since the service was due.
The schedule is considered flexible because is not tightly tied to mileage. Several conditions can affect the service timing, including driving in dusty, muddy or wet terrain, repeated short trips without complete engine warm-up, extreme outside temperatures and operating the Mercedes Benz in high altitude or mountainous locales. Even though this service system has flexible timing, in general, Mercedes-Benz owners should expect to need either Service A or Service B every 10,000 to 13,000 miles, alternating between the two types.