Turn the key but not all the way to start the engine,
Toggle the menu until mileage is displayed.
Press the button sticking through the clear perspex 3 times, itwill beep
It will display UB and a number.
This is the voltage. At this point it should be around the 12-12.5v mark, the battery voltage.
Start the engine, the reading will drop momentarily to 11ish then should read 14-14.5v which shows the alternator is charging at the correct rate. It should not exceed 14.5v
Hope this helps
