Add up the digits Example: A123457 will lead to 2+3+4+5+7 = 21.

Push the right button until you see "Test Nr.19".

Enter the total amount calculated above into this menu item using the LEFT button. When complete press the right button again. This will unlock your instrument cluster giving you full access to all of the test modes

Using the left button select Test Number 9. System Voltage.

Press the Right button to select. Your battery voltage will show on the High Cluster until you turn the car off again