1. Turn Radio Off.
2. Turn Radio On.
3. Press and hold the "m" button for about 10 seconds.
4. Press < or > to navigate, you will need to go to the 2nd screen to look for the SW Verison which is in a SV xx-xx xx format.
5. To be Sirius/AUX or XM compatible, the radio must be SW 43 or higher.
6. Turn radio off to exit.
The MODE button is not a good enough of an indicator to check if a radio is AUX or Sirius compatible. It needs to be manufactured 09/02 or later.