1) put key in ignition
2) turn key to position 1
3) toggle menu to overall mileage screen
4) turn key to off position
5) turn key back to position 1
6) press odometer reset button 3 times quickly
7) screen automatically shows battery voltage
8) toggle through pages using steering wheel control until it gets to dynomometer page
9) use +/- buttons to choose ON
10) Turn ignition on and car will be in dyno mode at that point. You will know for sure when the display toggles through ESP/ABS/BAS screens.
*If menu is already set to display overall mileage screen, you can skip steps 4 and 5.
**Overall mileage does NOT have to be set to zero for this to work.