Since 1997, most Mercedes-Benz vehicles come equipped with an electronic computer system linked to the dashboard that tells drivers when the engine needs to be serviced. A wrench-shaped symbol will display on the dashboard instrument panel, including a message that reads “Service A,” “Service B,” and, with the ASSYST PLUS system, all the way through “Service H.” These messages indicate what service package is needed, with “Service A” being a simpler, less time-consuming service package than “Service B,” and so on. Below the message, an odometer will count down, indicating how many miles are left before the service is due. If the driver neglects a service light, he or she runs the risk of damaging the engine, or worse - ending up stranded on the side of the road or causing an accident.
For these reasons, performing all scheduled and recommended maintenance on your vehicle is imperative to keep it running well, so you can avoid the many untimely, inconvenient, and possibly expensive repairs that come from neglect. Luckily, the days of scratching your head and performing diagnostics to find the service light’s trigger are gone. Mercedes-Benz’s ASSYST maintenance reminder system is an on-board computer system that alerts owners about maintenance needs so they can address the issue promptly and without hassle.
At its most basic level, the system actively monitors engine and other vehicle components for wear with special sensors and algorithms, which help determine how many miles are needed between service periods. This is dependent upon many factors, including driving habits and environmental factors. Once the ASSYST maintenance reminder system is triggered, the driver knows to schedule an appointment to take the vehicle in for servicing.
How the Mercedes-Benz ASSYST maintenance reminder system works and what to expect
The sole function of Mercedes-Benz’s ASSYST maintenance reminder system is as a reminder for a driver to take the car in for an oil change and other routine maintenance as outlined in the standard maintenance schedule. The computer system uses sensors and algorithms to keep track of certain vehicle components, such as the oil life, brake pads, brake fluid, spark plugs, and other important engine components. The vehicle will display the number of miles before or the date when a certain service is due on the dashboard when the vehicle is turned on.
The system is set to trigger between 9,000-15,500 miles, between 12 and 24 months, or whichever comes first. Once the system is triggered and the mileage and/or time countdown has completed, it will display a message indicating that the driver should “CARRY OUT SERVICE,” letting the driver know that it is time to schedule an appointment to have the vehicle serviced immediately. If your Mercedes-Benz service indicator is telling you to “CARRY OUT SERVICE,” or the vehicle hasn’t been serviced within one to two years as recommended according to year and model, it is imperative to take your vehicle in for servicing as soon as possible.
Additionally, the Mercedes-Benz ASSYST maintenance reminder system is algorithm-driven, and takes into account the differences between light and extreme driving conditions, load weight, towing, or weather conditions - important variables that affect oil life. Even though the vehicle monitors the engine itself, it is still very important to be aware of your driving conditions throughout the year and, as necessary, have a professional determine whether or not your vehicle needs servicing depending on your specific, most frequent driving conditions.
Below is a helpful table that can give you an idea of how often you might need to change the oil in a modern vehicle (older vehicles often need more frequent oil changes):
- Note: Engine oil life is dependent not only on the factors listed above, but also on your specific vehicle model, year, and what type of oil is recommended. Check the owner’s manual for more information about what oil is recommended for your vehicle, and don’t hesitate to get in touch with one of our experienced professionals for advice.
When the wrench-shaped symbol is triggered and you schedule an appointment to have your vehicle serviced, Mercedes-Benz recommends a series of inspections that will help keep your car in good running order and can help prevent untimely and costly damages to the engine, depending on your driving habits and conditions.
Below is a graph of Mercedes-Benz’s recommended inspections for different mile intervals. This graph is a general depiction of what a Mercedes-Benz maintenance schedule can look like. Depending on variables, like the vehicle year and model and your specific driving habits and conditions, this information is subject to change for maintenance frequency as well as the maintenance performed.
While the vehicle operating conditions are calculated according to the condition-based maintenance system that takes into account driving styles and other specific driving conditions, other maintenance information is based on standard timetables such as those in old-school maintenance schedules, located in the owner’s manual or within the computer system itself. Schedule C-H maintenance schedules are time-dependent schedules that indicate a certain amount of hours necessary for the maintenance period; i.e., Schedule C is a three-hour service, D is a four-hour service, and so on. The specific maintenance tasks needed are solely dependent upon the vehicle itself; the servicing information of which is stored in the computer, which the mechanic will extract upon servicing.
Proper maintenance service will greatly extend the life of a vehicle, ensuring it is reliable, safe to drive, covered by the manufacturer’s warranty, and it also provides a greater resale value. Such maintenance tasks should always be performed by a qualified technician. If you have any doubts as to what the Mercedes-Benz ASSYST maintenance reminder system means or what services your vehicle may need, do not hesitate to contact our experienced professionals for advice.
If your Mercedes-Benz ASSYST maintenance reminder system is indicating that your vehicle is ready for servicing, have it checked out by a certified mechanic, such as one from YourMechanic. Click here, choose your vehicle and service or service package, and book an appointment with us today. One of our certified mechanics will come to your home or office to service your vehicle.
This article originally appeared on YourMechanic.com as Understanding the Mercedes-Benz Active Service System (ASSYST, ASSYST PLUS, ASSYST Fixed Intervals) Service Indicator Lights and was authored by Brent Minderler.