W216 Dyno-Mode
Get in the car, shut the door and turn the ignition key to the first accessory position, making sure the odometer miles are showing.
Press and hold the make call button, within 1 second, press the OK button and hold both for 5 seconds.
You should see:

Scroll down to highlight:

Press OK to confirm, and you should see:

Press OK again, start engine, you should see these two messages:


you are now in Dyno Mode.
You can also reset and check the service reminders from this screen.








