If you don't have a genuine Xentry subscription:
If Xentry is unavailable, some W204, W212, W166, etc., support button sequences: xentry service reset
You can reset the service indicator on many Mercedes models using the steering wheel buttons (hitting the phone/ok button while scrolling to the trip odometer). However, this manual method has severe limitations: If you don't have a genuine Xentry subscription:
Click the or Setting icon (sometimes labeled as "Step 4" in the software). xentry service reset
With Xentry, you are not just resetting a light. You are: