One of the defining features of the Mercedes-Benz ownership experience is the ASSYST PLUS system. This intelligent onboard computer monitors your driving habits, engine temperatures, and trip durations to notify you exactly when your car needs attention. However, after the oil has been changed and the filters replaced, the persistent “Service A Due” or “Service B Exceeded” message must be cleared manually.
In this guide, we will walk you through the manual reset procedures for modern Mercedes-Benz models and explain why Mercedes-Benz scheduled maintenance is about far more than just turning off a light.
Why the Service Light Matters
The service warning light is not a simple timer; it is a critical communication tool between your vehicle and its driver. In 2026, Mercedes-Benz models continue to use sophisticated algorithms to alternate between Service A (minor service) and Service B (major service).
Resetting the light without performing the actual work is highly discouraged. It desynchronizes the car’s maintenance history and can lead to missed fluid flushes or safety inspections. If your light has come on, the experts at Amayak Auto are here to ensure the work is done to factory standards before the indicator is cleared.
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How to Reset the Light (Step-by-Step)
The procedure varies by “generation” of steering wheel and dashboard interface. Here are the steps for the most common modern configurations found in 2024–2026 models.
For Newer Models (Touch-Control Steering Wheels)
Models: W206 C-Class, W223 S-Class, EQ Series, and 2024+ GLC/GLE
- Preparation: Close all doors and the hood. Sit in the driver’s seat.
- Position 1: Press the Start/Stop button once (without your foot on the brake) to enter Ignition Position 1.
- The “Secret” Combo: Ensure the “Trip” or “Mileage” is displayed on the cluster. Press and hold the Home button on the left side of the steering wheel for 10 seconds.
- Enter Workshop Menu: While still holding Home, immediately press the OK (or center touch pad) button for another 5 seconds.
- Navigate to ASSYST PLUS: A “Workshop” menu will appear. Scroll down to ASSYST PLUS.
- Ignition Position 2: The screen will ask you to “Switch on ignition.” Press the Start/Stop button one more time (still without the brake).
- Confirm Full Service: Navigate to Full Service > Confirm Service. Select the oil grade used and confirm. The message “Full Service Carried Out” should appear.
For Previous Generation (Physical Button Steering Wheels)
Models: 2016–2023 E-Class, GLC, GLE, and A-Class
- Position 1: Turn the key to position 1 or press the Start/Stop button once.
- Highlight Trip: Use the steering wheel buttons to highlight the Trip menu.
- The Combo: Press and hold the Back/Return button and the Touchpad/OK button simultaneously for 5-10 seconds.
- Vehicle Data: The “Vehicle Data” menu will appear. Scroll to ASSYST PLUS and follow the prompts to “Confirm Full Service.”
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The Amayak Auto Difference
At Amayak Auto, located at 1136 Queens Ave in New Westminster, our history dates back to 1915, with our shop officially carrying on the legacy of our founder, Amayak, since 1999. We are a 100% family-owned business that treats every Mercedes-Benz like a piece of our own history.
We understand that Mercedes scheduled maintenance requires precision. When you bring your car to us, we don’t just reset the light; we use factory-level diagnostic tools to perform the full scope of Service A or B. This includes checking the brake system, suspension, and steering components that a DIY reset simply cannot address. We provide a transparent, digital report for every service, ensuring your Mercedes remains the high-performance machine it was engineered to be.
Conclusion & Takeaways
Resetting your service light is the final step of a job well done, not a shortcut to skip maintenance.
- Service A vs. B: Remember that Mercedes alternates these services every 10,000 miles (16,000 km) or 1 year.
- Safety First: The reset menu allows you to see “Service Data,” which can tell you exactly which additional items (like spark plugs or transmission fluid) are due.
- Documentation: A professional reset at Amayak Auto ensures your digital service booklet is kept up to date, which is vital for your car’s resale value.
Frequently Asked Questions (FAQs)
1. Can I reset the light myself if I change my own oil?
Yes, you can manually reset the light using the steps above. However, ensure you are using the correct Mercedes-approved synthetic oil (e.g., MB 229.5 or 229.71) to prevent engine damage and maintain your warranty.
2. What happens if I accidentally confirm the wrong service?
If you accidentally confirm a “Full Service” that wasn’t performed, it can be difficult to undo without specialized diagnostic software. If this happens, bring your vehicle to Amayak Auto, where we can use our professional scanners to correct the maintenance interval.
3. Why won’t the workshop menu appear when I hold the buttons?
The most common reason is the ignition position. Ensure you are in “Position 1” (electronics on, but dashboard not fully lit with all warning lights). Also, ensure the “Mileage” or “Trip” counter is the main view on the screen before starting the button combo.
4. Does resetting the service light also reset the “Check Engine” light?
No. The service indicator is a maintenance timer. The “Check Engine” light (MIL) indicates a fault in the engine’s emissions or mechanical systems. A fault light requires a diagnostic scan at Amayak Auto to identify the specific error code.
5. How much does Mercedes scheduled maintenance cost at Amayak Auto?
Costs vary by model and the specific service required (A or B). Generally, our services offer significant savings over dealership prices while utilizing the same high-quality OEM parts and certified expertise.
