These instructions apply to the Mercedes A-Class Mk4 (W177) 2018-Present. For other models, please choose your vehicle here.
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When the spanner or an “ASSYST PLUS” service message appears on your Mercedes A-Class Mk4 (W177, 2018–present), the service interval has elapsed. Mercedes uses its ASSYST PLUS menu, reached through the instrument cluster, to reset it. It’s a few more steps than most cars, but no tools are needed. Do the service first, then follow the sequence carefully.
Reset Only After the Service
ASSYST PLUS records the actual service that’s been done, so only confirm it once the oil and filter are genuinely changed.
How to Reset the A-Class W177 Service (ASSYST PLUS)
- Close the bonnet, all doors and the boot. Turn the ignition to position 2 (on, engine off).
- Using the steering-wheel buttons, press the right-hand display button until the standard (Trip) display shows, and scroll to the ‘Trip’ menu.
- To open the hidden menu: press and hold the right-hand display button, and within 1 second also press the left-hand button; keep both pressed for about 5 seconds.
- The ‘Workshop’ menu appears (Vehicle data / Dynamometer test / ASSYST PLUS). Select ‘ASSYST PLUS’.
- Select ‘Full service’, then ‘Confirm service’.
- Select the oil specification you used, then ‘Yes’. A “cannot be undone” warning appears; confirm until the display shows ‘Confirmation’.
If You Make a Mistake
The confirmation can’t be reversed, so take care to select the correct service and oil spec. If you only want to top up the remaining distance rather than confirm a full service, exit without confirming.
Frequently Asked Questions
What is ASSYST PLUS?
It’s Mercedes’ active service system — it tracks the actual service work and oil used, not just mileage. You confirm the completed service through its menu.
Do I need a diagnostic tool?
No — the reset is done from the steering-wheel buttons and the cluster menu.
Why does it ask for the oil specification?
ASSYST PLUS adjusts the next interval to the oil quality used, so it asks you to confirm the spec.
The service message is still there — why?
You may not have reached ‘Confirmation’. Repeat carefully through Full service → Confirm service.
If a warning light appeared with the service message, look it up on autodtcs.com. After battery work, see our A-Class W177 battery guide.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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